Damp Proofing Services from Be Dri

Damp proofing faults cause  damp problems and you will probably start to Damp proofing Bournemouth and Dorset an old wall in limelite replacement sand & lime in Bournemouth Poole Weymouth Dorchester Blandford Swanage Wimborne Wareham Dorsetwonder what is causing it. And that it might just be getting worse and starting to spread. As it spreads its starts to lift the wall paper and leaves it with a dirty stain. You might even have black mould, old musty smells around the house in cupboards and on clothes and in the carpets.

Damp proofing Mesh Tanking Membranes for your cellar / basement conversion Bournemouth Poole Weymouth Dorchester Blandford Swanage Wimborne Wareham Dorset

Be Dri can offer damp proofing for all types of damp. We can help you, we want to take away your damp problem and what’s causing it. We have years of experience in dealing with older properties and many of the common problems . We have the knowledge and the expertise to offer you the best damp proofing services to remove the damp and cure the problem in your home.

When we hear “Damp problems found” theseDamp proofing Limelite sand and lime heritage replacement plaster used around a converted coal fireplace Bournemouth Poole Weymouth Dorchester Blandford Swanage Wimborne Wareham Dorset are words you do not want to see in your Home buyer’s survey report. They will give some people restless nights. The reason there is such nervousness about damp is that it causes many other problems. Such as timber decay and woodworm infestations and ruins plaster.

There are several causes of damp in buildings these are rising damp, Damp proofing a cavity wall by installing a french drain in Bournemouth Poole Weymouth Dorchester Blandford Swanage Wimborne Wareham Dorsetpenetrating damp, condensation and hygroscopic salts.

These types of damp all look very similar. But what causes them are completely different and the way they should be treated is also different. That is why we are experts at getting to the cause. Finding the problem and diagnosing what the fault is. Then using the correct damp proofing method to cure it.


Damp Solutions

Damp proofing solutions help and advice in Bournemouth Poole Weymouth Dorchester Blandford Swanage Wimborne Wareham DorsetWhen the team from Be Dri damp proofing Solutions arrive on a job. We aim to provide a fast, efficient and friendly service to our customers.

Our highly trained surveyors and technicians will investigate fully. And will go out of their way to provide complete customer satisfaction from the moment they step in your home. You can put your full trust in our damp proofing solutions as we transform your damp house into a dry, warm home.


Damp Proofing Problems in Period Houses

Heavy condensation causing wall paper to peel awayDampness in old buildings is often the result of several problems in combination (See fault page). Such as external ground levels to high, cavity wall full of old building debris, poor pointing and condensation. The presence of damp is not always obvious. structural floor timbers may already be rotting away before there are any obvious damp patches at skirting board level.Vast amount of building material in the cavity causing penetrating damp

To make things worse for customers is that there are several types of damp. And the main ones such as rising damp, penetrating damp and salt contamination.

They all look very similar but they all have different damp treatments and damp cures.Penetrating damp causing damp on the inner wall ruining decoration and plasterwork


Damp Causes

The predominant problems arising with damp in older houses is penetrating damp, property faults and condensation. These are caused by a lack of maintenance or problems at ground level.Stepped foundations and concrete plinth exposed during pentrating damp problem

Also where the property has been modernised and double glazing added and no modern extraction has been installed. In the cooking or the bathroom areas the property’s humidity levels rise this becomes trapped in the house. Rising damp is rarely found because most property’s still have an original dpc. Made from flint or a sand, ash and bitumen mix and in some case engineering bricks.

Cavity Wall Clearance

Corroding sash weights found during cavity wall clearanceCavity wall damp problems can look like a rising damp issue on the internal walls this is because the cavity wall is full of rubble and building debris.

This penetrating damp fault can be removed by cavity wall cleaning. Wall of a Victorian home exposed to gain access due to internal damp problemsOnce this work has been completed the brickwork at floor level will start to dry out. As the moisture is allowed to evaporate away. We specialise in period property cavity wall clearance and unblocking air vents and restoring sub floor ventilation.

Damp Proof Courses

New Dpc fitted during cavity wall clean out to stop any future rising damp problemsDamp proof courses were not regularly installed in any building construction method until the introduction of the Public Health Act in 1875. Three years later the Building Act of 1878 provided more detail on the types of constructions and the regulation of their construction.

They were regularly installed after this so by the time of the great Victorian building boom of 1880 they had become commonly installed. Rising damp would normally only affect a property if a small part had been broken during some other building works at that level.

Other Damp Proofing Companies

Many damp proofing companies just treat it all as rising damp with cement based products. Trying to just block the damp out and insisting you Hydroscopic salt stain caused by internal condensation and not rising damp or penetrating dampneed another DPC which will have to be chemically injected.

This method has proven to be the wrong long term approach and is showing up as failed crumbling pink gypsum plasterwork. It will have a high salt content due to humidity problems in old houses. This will appear within 2 – 25 years of this using this method of cement and gypsum plaster based renders in old houses.

This stain looks like rising and penetrating damp and appears to show Dpc failure but it’s not the humidity is causing it.

So as the work is guaranteed for Dpc failure only you will have to pay again to have it plastered to stop the hygroscopic salts constantly absorbing moisture from the atmosphere and making your wall look a mess.


On the following tabs you find detailed descriptions of the most common types of damp found in your property.

Below, you can read more about treatments available to remedy damp.

Penetrating damp specialist can show you how moisture comes through the wall instead of up them this can appear at any level. This penetration can be caused by external ground levels being higher than the property’s dpc or were poor Penetrating damp specialist Dorset removing vast amounts of material from cavity wallspointing and driving rain saturates the wall.

When driving rain is the cause it leaves brown patchy stains on the wallpaper or the internal Penetrating damp specialist showing how a cavity should after it has been clearedplasterwork.

Also over time and poor building practices on the original build the cavities are filled with brick Penetrating damp specialist removing old sash weights from a Victorian houserubble, broken slate, timber and weights from the old sash windows when the double glazing was installed. You would be amazed at the amount of debris that can be removed from a cavity wall clean out it can be by the wheel barrow load.

Penetrating damp specialist finds the cause of moisture on the internal wall due to the cement render touching the floorThe debris in between the cavity gets wet and this moisture Penetrating damp specialist finds another blocked cavity causing Penetrating damp transfers on to the internal wall the damp on the inner wall looks like rising damp if not diagnosed properly.

We have removed over 300kg’s of building rubble from blocked cavities in a small 3 bedroom Victorian home.


Penetrating Damp Coming through Walls

There are specific places where penetrating damp will commonly Penetrating damp specialist removing a vast amount of building material from another Victorian semi detached home in Dorsetenter the property. The window sills are usually made of stone or rendered brick and over the years with movement and the mortar around them cracks allowing water to run in behind them and down the cavity.

This water will flow over the internal brickwork down to the base of Penetrating damp specialist finds blocked cavity's are the problem in this Edwardian Housethe cavity resulting in damp around the skirting boards and the floor joists.

Early Victorian property’s floor joists were built into the wall so this type of water penetration will rot your sub floor joists.

Penetrating damp specialist finds a sache weight stuck amongst brickwork causing moisture to penetrate across the cavity to rot your timber skirting boards

 Penetrating Damp Internal Walls

Penetrating damp specialist has to remove the concrete plinth in order to remove building rubble in a cavity

Property faults and poor maintenance cause continuous damp spots these areas become saturated from this heavy wetting. Faulty gutter union jointers and blocked down pipes, causes walls to become saturated this will cause damp to appear at low levels.

Other areas such as doors and window frames suffer similar problems with water penetration between frame and wall when the mortar has become poor. More common sources of dampness includes faulty plumbing, rising damp through the floor, adjoining garden walls and creeping plants such as ivy who’s roots travel through soft sand and lime mortar beds into the cavity or through solid walls. The roots will get larger and force the mortar out and will let more water in.

Penetrating damp specialist find damp to lower walls around skirting board height

Penetrating Damp Cure

Even when the sources of dampness have been removed it can still take many Penetrating damp specialist finds that trapped moisture is causing gypsum plaster to show hydroscopic salt damagemonths for the material to dry out. And when dampness is drying out it can look like the same as the original problem, especially

If gypsum plasters are used to finish and they have absorbed salts.

Penetrating damp specialist has to repasted using breathable plaster

Penetrating damp specialist removes another wheel barrow of rubble from a blocked cavity wallThis is why it is important to remove all sources of dampness and to re plaster with the correct materials and use the right plastering system.

Penetrating Damp Survey

Penetrating damp specialist surveys in DorsetPenetrating Damp is the biggest damp problem affecting Period houses today. This type of damp causes numerous dampness issues trapping moisture around the base of the building. The signs of these faults could be eroding bricks or walls with interior showing signs dampness.

Penetrating damp specialist finds wet material in the cavity wall and compacts it into a ball due to the moisture level

Our surveyor will be happy to attend and give on sight advice and a written report if required for Mortgage Purposes on penetrating damp.

Customer ServicePenetrating damp specialist customer service Dorset

Don’t be damp Be Dri call us today and let us help you with any of your damp proofing, woodworm treatments, wall tie replacement, repointing brickwork and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions.

Condensation problems are another type of damp problem which is greatly overlooked because people don’t understand it or notice it because high humidity (warm damp air) is causing this to happen and condensing back into water vapour every night after the heating goes off and the walls get cold again.

Condensation problems on glass windows

Condensing back into water droplets on the same part wall every day will start to draw moisture through the wall. This continuous action will cause the hydroscopic salts in the building material to start to cause stains in the wall which look wet and like rising damp and penetrating damp. When at its extreme it will look like rock salt coming out of your plasterwork especially if the wall has been re-plastered with pink gypsum plaster with a sand and cement render backing. Again wrong materials in old houses it doesn’t breathe and let moisture through the wall to evaporate.Kitchen extration for condensation problemsPositive pressure systems for house condensation problems

Condensation is caused by excessive indoor humidity which is created by us living inside the property. Every day living for a family of 4 includes cooking, breathing, drying clothes, washing up, baths and showers, washing machine, kettle, plants and pets can create up to 12 litres of water vapour a day.

Condensation Problems on  Windows and Walls

Condensation problems causing black mould on windows

This vapour has to go somewhere so its effects appear on and around cold surfaces such as windows and on walls near the skirting boards. The reason it affects the lower wall is because this is where the wall / floor come together and is the coldest part of any internal wall.

Ceilings also suffer from condensation and will attract speckled fungal growth. Other common places to find heavy mould growth is behind bulky furniture and unventilated cupboards where there is no air movement.

Condensation Health Risks

Excessive long term humidity will affect clothes and carpets which will smell mustCondensation problems causing black mould growth on a wet wall in a bedroomy and will be damp to touch due to excessive mould spores this is not a healthy option.

With increasing energy costs sealing up old houses to prevent all draughts has become the normal thing do but this is trapping lots of moisture in your home on a daily basis. With no outlet for the moisture this starts to cause musty old smells, clammy plaster and black mould spores, which start to drift around the house settling in cupboards and on your clothes

Damp and Mould Health Risks

These damp conditions long term can exacerbate bronchial and asthmatic conditions due to excessive damp conditions in bedroom areas.

Aspergillus Niger and similar moulds are hydrophilic fungi; that is Condensation problems causing Aspergillus Niger and similar moulds look like this under the microscope
they require high levels of surface moisture. Capillary held dampness is not sufficient to cause mould growth. The mould requires free moisture on the surface.

Condensation  Problem Cures

Condensation can be reduced by regular heating and improved frequent ventilation to the property. Building regulations today insist on extraction in Bathrooms and kitchens.Condensation problems can be removed using inline extration

It is recommended that extra ventilation is introduced into the property by installing bathroom/kitchen fans and the installation of a positive pressure unit to the property.

We can assist you in a selection of British made fans with 3 year guarantees that can adequately remove you excessive moisture levels and have them set and install by a professional qualified electrician.

Condensation Problem Survey Condensation problem survey

We all deserve fresh, clean air in our homes so let us help you improve or upgrade your current ventilation requirements. We are a mould and condensation Specialist Control Company.

Our surveyors will help you choose the right fan for your rooms and property.

Call today to stop your condensation problems.

Condensation and Thermal Bridging

It is a well-known fact that warm air will hold far more water vapour than cold air. A well-insulated room can be very humid especially rooms like kitchens and bathrooms. In some properties this won’t be a problem but in older houses if this humid air leaks through gaps in floors, walls and ceilings then when it comes into contact with a colder surface it will quickly cool down and condense back into water. If you have lined your walls then the wall behind will now be colder. And any humid air that manages to make contact will condense back into water and start running down the wall to wooden floors and joists and remain trapped within the building. This type of damp is known as interstitial condensation. Now because this damp can go unnoticed for long periods serious decay can take effect.

Condensation problems and high humidity are causing hydroscopic salts to make this stain

Damp from condensation will also effect areas where insulation has been missed or it isn’t thick enough this will cause thermal bridging. This is where the outside cold air will penetrate the building. The normal cold spot are around reveals around the openings for windows and doors and the upstairs ceilings near the eaves.

Condensation problems are causing this gypsum plaster to crumble due to hydroscopic salts in the material it's self

Condensation Problems Customer Service

Don’t be damp Be Dri call us today and let us help you with any of your condensation, damp proofing, woodworm treatments, wall tie replacement, repointing brickwork, and wet and dry rot issues.

It’s free to call and costs nothing to ask your Condensation problems ask for customer services


Is Rising Damp Real or Myth?

True rising damp is rarer than most people would have you believe.Rising damp in this 18th century property because there is no dpc as he had'nt been invented yet Most damp is due to property faults which show up on the inside of the property as stains or what looks like damp patches due to salt contamination or penetrating damp issues in cavities.

Rising damp in this solid brick wall cottageRising damp appears in some properties 15th 17th Century buildings if the damp course is too high and the joists are laid directly onto the sub soil or are attached to the walls then timber rot appears. Other reasons for damp in a wall are that the original DPC was broken during some building work.

What the Experts Say about Rising Damp

Some experts such as the RICS Conservation a professional body of people qualified with the experience and knowledge in the field of conservation of historic buildings or sites also believe that the chances of true rising damp is in people’s homes is very low and rare.

Looks like Rising Damp

Rising damp looks like other forms of damp, like penetrating damp and condensation which are commonly found in the home.

The two main reasons for moisture at the lower wall level is high external ground levels where paths or soil are higher than the original DPC causing moisture to force its way through the wall. AndRising damp in a property without a dpc you can see the moisture coming through the plaster from blocked drains and leaking gutters causing excessively damp soil or brickwork over a long period of time this all causes penetrating damp problems. Other building faults or improvements will also makes these problems even worse. They are blocked cavity’s full of building debris common in old houses and wet cavity wall insulation.

Condensation in the home is another form of damp which look like a damp problem. Warm air in the house will condense back to water when it touches a cold wall surface and will then run down the wall and soak into the plaster. When on cold days when the heating is on in the house the internal humidity rises above 55% this humidity brings out a stain which looks like rising damp


Rising Damp Survey

A genuinely honest surveyor should spot all these signs and be able to diagnose correctly the faults with your property and then recommend any require damp treatment for rising damp. Much harm can come from mistaken diagnose and not correctly identifying the faults with your property.

Rising damp survey

If your property didn’t need a new DPC and they drill into your property with hammer drills there will be a 10mm hole at the front of the brick and the rear of the brick will be smashed and broken as the drill punches through. Made worse if the bricks are showing signs of spalling already because old bricks are a lot softer then you think and shatter easily.

Rising Damp Experience

So if musty old smells, clammy plaster and spongy floors are what you are experiencing at the moment this needn’t be a problem if the dampness in the brickwork is allowed to evaporate freely in dry weather.

Rising damp caused due to the dpc being installed to high and the old floor is to low

And the sub floor area has good air flow created by good ventilation by the external air bricks this will create the correct conditions for your property to expel excess moisture breathability and evaporation are the remedies for rising damp concerns.

We understand what causes  damp and have the damp proofing expertise and knowledge to give you best advice on your specific rising damp problem and damp issues causing you concern in your home.

Customer ServiceRising damp customer service

Don’t be damp Be Dri call us today and let us help you with any of your damp proofing, woodworm treatments, wall tie replacement, repointing brickwork and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions.

Below you will find a list of damp treatments and remedial works to remedy and prevent damp ingress.

Damp Information 

Damp Effects in Buildings

Damp Information for damp proofing that is used in the construction industry as a barrier. Damp information about damp effects in buildingsIn conjunction with other building practices to prevent moisture from passing from the external to the internal. The barriers are designed to stop moisture travelling vertically or horizontally through porous material such brick, block or render.

Information for damp proofing material that is defined as a material that resists the passage of water. With no hydrostatic pressure and waterproof as a treatment that resists the passage of water under pressure.

The consequences of dampness in buildings can range from the trivial. like mould around a window seal to the catastrophic such as floor joist and main support timbers collapsing.

These are some of the most common problems found in properties. Which suffer from some form of dampness and the reasons damp proofing is required to remedy these damp issues.

  • Visible Dampness
  • Hydroscopic Salts
  • Fungal Decay Damp
  • Damp Mould Growth
  • Damp Deterioration
  • Damp Health Hazard
  • Damp Corrosion
  • Increased Heat Loss Damp

In many cases, the consequences of dampness will include a combination of these effects and will require several damp proofing solutions to remedy the problem.


Visible Dampness

Damp information for visible dampness problems that are unsightly but may be ignored by the occupant of a building. If they only appear to affect the external surface of the building.

Staining of the external walls of a building by Damp information about visible dampnesswater from defectives. Such as down pipes and gutters or by earth bridging horizontal damp proof courses. And faulty water overflow pipes seems sometimes to be considered as enchanting the character of the property.

However, buildings will only accept a limited amount of punishment and if the warning signs are not recognised. Then far more serious consequences will eventually result from such neglect.

Internal Visible Dampness

Internally, visible dampness problems are taken more seriously. If they are continuing problems, especially if they affect the internal decoration.

An established rising damp or penetrating damp problem may mean that the lower part of the wall always appears to be wet. And that no matter how often the internal decorations are renewed, deterioration quickly occurs.

Transient dampness problems, however, may well be conveniently ignored due to lack of understanding as to the hidden consequences that may exist. For example, condensation on a window is easily dealt with by regular use of a cloth until the time that extensive fungal decay becomes evident in the timber frame.

It is important to realise that though the visible consequences of dampness within and outside the building. It may appear of little importance, the consequences could be very serious.

Hence the survey of a building related to possible dampness problems has to take this into account. And then identify the hidden consequences associated with the visible problems, for example:

If one wall of a building has a visible dampness problem due to rising damp. Then do the other walls also have rising damp even though the problem is not yet visible?

If the cause of dampness has been identified for a visible problem on the walls of a building. Is there a hidden problem (Fungal decay) affecting the timber in contact with those wet walls?

Hydroscopic Salts

Damp information about salts that may cause problems in buildings for a number of different reasons:

  1. They may appear as unsightly surface deposits (efflorescence) on the internal or external surfaces. Damp information about hydroscopic saltsAnd the continual need to be brushed off to maintain the appearance of the building.

They may crystallise below the surface and disrupt the surface of the material. Common examples are:

The Crystallisation of salts beneath the surface of the external facing brickwork, this will lead to spalling of the brick face.

The Crystallisation of salts on the surface of brickwork and below the plaster finish, this will show on internal wall surfaces leading to disruption of the plaster finish.

  1. They may chemically attack materials within the building fabric, for example:

Damp information about salts in buildings ruining gypsum plasterSulphates chemically react with Portland cement and if the sulphate concentration is high enough. The deterioration of Portland cement based materials (mortar, internal plaster, external render) will occur. These Chlorides will corrode copper and cause extensive deterioration of copper water pipes.

They may be hydroscopic which means that the material. In which they are contained will become wet under high humidity conditions.

In all cases the salts are in the material to stay, unless they can be transported by water to the surface of the material. Or unless the material it’s self is removed and in some cases there is no simple answer to the problem that exists.

It is important to remember that the salts only cause a problem if there is a source of water available to them. And if they are present in sufficient quantity. Therefore, if the source of the water can be removed, the consequences can be eliminated.

This is precisely what should happen when a wall is re plastered following a rising damp treatment.

Fugal Decay Damp

Damp information about the attack of timber by wood rotting fungi will only occur if the Damp information about fungal decay in buildingsfollowing five conditions are met.

  • A source of infection (a fungal spore)
  • A supply of food (Timber)
  • A supply of oxygen (Air)
  • A suitable humidity (60%+)
  • A water supply

In most buildings, the first four conditions are usually satisfied and so the source of moisture is the trigger for fungal decay to occur.

In any building in which there is a dampness problem. It should be assumed that there is likely to be an associated fungal decay problem with the timbers. In the vicinity of the wet areas, this should be taken into account during any survey for dampness in buildings.

 Damp Mould Growth

Damp information about the disfiguration of surfaces mould growth by is common in Damp information about mould growth in buildingsbuildings with a dampness problem. Though the occurrence of such mould growth should not be taken as indicating any particular type of dampness condition.

Moulds are simply another type of fungi, which feed of the deposits which collect on the surface of materials but which cause no real damage to that material.

The presence of mould growth in a building may indicate that a dampness problem exists. Or may simply be the result of high humidity conditions within the building.

It should be not therefore be assumed that the resolution of a known dampness problem will eliminate mould growth. If the real cause of the problem is a high humidity condition. Then some additional course of action will also be necessary.

Damp Deterioration

Damp information about damp deterioration in buildingsDamp information about the continual wetting and drying of materials will often cause physical degradation of the material. Although obviously materials vary considerably in their tolerance to such conditions. Some common consequences are shown below:

The material expands as the moisture content increases and contracts. As the moisture content decreases resulting in cracks appearing in the material. Common examples of this are the cracking of internal plaster, external renders, timber and surface coatings, such as paint.

If the material is rigidly fixed and expansion occurs, it may distort as well as crack. Common examples are distortion of timber skirting boards and the loss of adhesion to plasters and renders.

The material becomes wet, the temperature drops to below 4 C, and the water expands and eventually freezes at 0 C causing the face material to spall off.

This is commonly seen as frost damage to external facing brickwork.

The evaporation of water from the material is restricted by a coatingDamp information about problems caused by dampness to building materials on the face of the material. And results in the coating being forced off the face of the material.

The wetting and drying process cause salts to migrate and concentrate at or the surface of the material and lead to the problems described in Hydroscopic Salts.

Damp Health Hazard

Damp information about the relative humidity of air within a building can have an effect on occupants of the building.

Damp information about health hazards caused by long term damp problemsIf the relative humidity is low (below40%), water evaporates from the skin with relative ease and the body feels cold.

If the relative humidity is between 40% and 60%,. iit becomes more difficult for water to evaporate from the skin and the body temperature increase. At very high levels of relative humidity (80% to 90%). The result can be serve headaches and a general feeling of lethargy. Obviously, this situation is more likely to be encountered in buildings with dampness problems.

Additionally, if the dampness problem also has an associated fungal decay or surface mould growth problem. The presence of large quantities of fungal spores in the air can have an adverse effect on the health of the occupants.

Damp Corrosion

Damp information about water corroding iron based materials, such as steel wall ties. And inDamp information about about corrosion caused by damp in a building conjunction with salts, will also corrode other metals, such as copper. Hence, corrosion of metal components. Such as pipes, wall ties and timber connectors, in contact with wet materials can be a serious problem.

Increased Heat Loss Damp

As the moisture content of materials increases, so their ability to conduct heat increases. This clearly has some effect on the rate of heat loss from a building but, more importantly, increases the risk that condensation may occur.

Damp Proofing Survey

The need for the correct damp proofing advice is so important. ThereDamp information and advice damp surveys in Bournemouth Poole Weymouth Dorchester Wimborne Blandford Swanage Wareham Bridport Ringwood Christchurch Dorset are so many variables only our experienced surveyor can choose the best method of repair for your property.

Be Dri Customer Service

Don’t be damp Be Dri call us today and let us help you with any of your damp proofing, woodworm treatments, wall tie replacement, repointing brickwork and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions

Damp Treatment History

A damp treatment history through the 19th century most buildings in Europe were usually constructed from highly permeable materials such as stone and lime Damp treatment history for Victorian and Edwardian Housesbased mortars and renders with water based paints which allowed any damp to diffuse into the air by means of evaporation.

The later application of impermeable materials which prevent the natural dispersion of damp, such as tiles, cement and gypsum based materials and synthetic paints is thought to be the most significant cause of damp problems in older buildings.

There are many damp proofing solutions for dealing with damp in existing buildings. The choice of which will largely be determined by the types of dampness that are effecting the building (e.g. penetrating damp, rising damp, hydroscopic damp and condensation).

In the modern era major changes have taken place in our domestic lifestyle in the last 50 years. Our use of heating, the nature and cost of fuel and the way we have reduced ventilation in buildings.

When houses were heated by open coal fires and where building regulations insisted on the installation of air bricks the risk of condensation was low. Where fuel prices have risen dramatically over the last decade, people have tried to save money by removing these vents to prevent low level drafts. Add installing double glazing without window vents. Then pumping their walls with cavity wall insulation suddenly finds high levels of condensation in the house and hydroscopic salts in the plaster.

The change in construction methods from brick walls as a single leaf construction wasn’t until late Victorian times when they started introducing cavity wall construction. Cavity wall construction became standard practice only after the war, 1945 onwards. The main aim of a cavity wall was to improve weather tightness and the incidences of rain penetration were reduced.

Damp proof courses were not regularly installed in any building construction method until the introduction of the Public Health Act in 1875. Three years later the Building Act of 1878 provided more detail with constructions- they defined foundations, damp proof courses, thickness of walls, ceiling heights, space between dwellings, under floor ventilation, ventilation of rooms, and size of windows.

The risk of rising damp through the floor should have been entirely removed with introduction of suspended wooden floors which started to be introduced in the late Victorian period. The problem was some have been laid on sleeper walls without a DPC. And others the floor joists are built into the wall, either where it’s below DPC or on internal walls where no DPC was ever installed originally. This has caused many common problems to appear from the ground up such as wet rot, dry rot and an increase in woodworm.

Damp Survey

Damp is the biggest problem affecting period houses today. Damp causes numerous issues trapping moisture around the base of the building. The signs of these faults could be eroding bricks or walls with interior showing signs dampness.

Our surveyor will be happy to attend and give on sight advice and a written report if required for Mortgage Purposes on damp.

Customer Service

Don’t be damp Be Dri call us today and let us help you with any of your damp proofing, woodworm treatments, wall tie replacement, repointing brickwork and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions.


Types of Damp Treatment

Damp treatment for rising damp involves either curing the source of the Damp treatment for concrete plinth problemsproblem or masking its effects.

Finding the cause of the problem is the key to any successful long term damp treatment. The property should be closely inspected to ensure the existing DPC has not been bridged. Remove any earth that is within 150mm of the DPC or is blocking air vents.

Remove any external render which is breaching DPC and add a bell cast, also remove internal render to above the DPC.

Damp Treatment French Drain

Improving drainage around the property and lowering pathways and drives to below D PC will allow the lower courses of bricks to Damp treatment and french drain solutionsevaporate excessive moisture during the drying phases. A simple damp treatment but effective method of reducing sustained wetting against the external brick work is to install a breather trench. This will allow rapid evaporation of moisture from the face of the external brick work.

Damp Treatment for Cavity Wall Clearances

Damp treatment for debris in a cavity wall removalAdequate sub floor ventilation is the most important component of any damp treatment so cavity walls should be checked and cleared of blockages that prevent the internal vent from allowing air to circulate under the sub floor.

Sub floor areas should be checked for wet and dry rot and anyDamp treatment for external walls with concrete plinth touching wet soil timber built into the internal walls or timbers lying on sleeper walls without an effect damp barrier.

Damp Treatment using a physical DPC

The only certain way of introducing an effective DPC is to insert a Damp treatment for a new dpc after cavirty wall worknew physical membrane. This technique requires cutting the old lime mortar bed joint through the entire thickness of a (9 inch) solid wall. An adapted chainsaw is usually used to cut out the mortar bed. The membrane inserted into the wall and new mortar is pushed back into the wall to complete the work.

There are disadvantages to this to this old traditional method which are cost, the time required and the disturbance which it will create.

Damp Treatment using Chemical Injection

These can be used in most types of structures, although rubbleDamp treatment for a modern house silicon injection not recommended for older houses infilled walls can be difficult to treat successfully. This damp treatment involves inserting specially formulated products into closely spaced holes in brick or mortar courses along a DPC line. Their efficiency depends on how well the product penetrates the damp structure and its subsequent success during curing.

Silicate or aluminum stearate water repellents are either injected at high pressure or transfused into the wall under gravity or at low pressure. High pressure systems are generally used with solvent based silicones and aluminum stearates; transfusion methods are limited to the application of water based silicones basically in the form of the water soluble sodium methyl siliconate. The water repellents are pore liners rather than blockers and so allow the passage of some water vapor whilst preventing the rise of liquid moisture.

The repellents are not intended as a damp proof barrier against a substantial positive pressure of water and are not suitable in basement areas subject to high water tables and penetrating damp.

New chemical injection products are known as creams or gels. The cream is a concentrated viscous silane / siloxane emulsion, inserted by a gun through 12mm diameter holes drilled at the base of the perpends and at intervals of up to 120mm along the mortar coarse.

 Damp Treatment using Ceramic Tube Vents

In 1919, during the Great War peace conference, a member of the British military delegation noticed something interesting in the Damp treatment that doesnt work the only trouble with a damp-proofing system which uses ceramic tubes is that it doesn't work due to physicsPalace of Versailles: a row of small circular vents along the bottom of a wall. After some inquiries the delegate – one General Brown – found that the vents concealed ceramic tubes set into the wall for damp proofing, a process that had been patented in 1908 by a Belgian, Monsieur Knapen.

General Brown introduced the Knapen tubes into Britain under license, and apparently enjoyed some commercial success with British Knapen Ltd before selling up. Ceramic tubes continue to be made, marketed and installed in British homes.

The only trouble with a damp-proofing system which uses ceramic tubes is that it doesn’t work.

At first sight, the idea of drilling holes in a wall to remove moisture might seem logical. After all, increasing the exposed surface area should assist evaporation, shouldn’t it? But there was always supposed to be more to the tubes than that. The fine pores of the ceramic clay would actually draw dampness out of brick and stone. The angle at which the tubes were stuck in the wall would cause the moist air to flow away by gravity. It was even thought that the Dutch clay from which the tubes were made had special properties.

But any physicist will tell you that the system cannot work because the finer the pores, the greater the capillary action, or suction – and this makes a material hold on to its moisture, not dry out by evaporation. Any evaporation at the surface of the tubes would cause a build-up of dissolved salts, which would attract moisture from the air and actually make the wall damper. These suspicions were verified by experimental work published in Germany in the 1960s. Ceramic tubes do not make walls dryer, and in some cases they can make them wetter.

Even the damp-proofing industry trade body, the British Wood Preserving and Damp Proofing Association (BWPDA) has a code of good practice which advises against using ceramic tubes.

But nobody in the building game ever let a few facts fog the issue. The contents of foreign-language science journals do not find their way easily into the British press. So 30 years after they were shown to be worthless, ceramic tubes are still being marketed, and even described in construction textbooks as a proven way of keeping walls dry.

Damp Treatment Survey

The need for the correct damp proofing advice is so important there Damp treatment surveys in Bournemouth Poole Weymouth Dorchester Swanage Wareham Blandford Wimborne Christchurch Bridportare so many variables only our experienced surveyor can choose the best method of repair for your property.

Damp Treatment Methods Types

Damp Proof Course (DPC)

The DPC is a barrier placed in the construction to prevent rising damp through capillary action. Rising damp is the effect of water rising from the ground into your property. The damp proof course may be horizontal or vertical. A DPC is layer is usually installed at least 150 mm above the ground. This will depend on the internal floor height.

The methods for installing a new DPC are described generally as “traditional” (the insertion of a physical DPC) or “nontraditional” (the use of barrier creams or silicon treatments under high or low pressure). We strongly recommend that you consider nontraditional methods only if it has been awarded an Agrément Certificate. Chemical injection is the only method that currently satisfies this requirement. Chemical injection systems can be used in most types of structure, although flint walls and rubble infilled walls can be difficult to treat.

Damp Proof Membrane (DPM)

The DPM is a membrane material applied to prevent moisture directly rising under the floor slab. A common example is polyethylene sheeting laid under a concrete slab to prevent the concrete from gaining moisture through capillary action.

Integral Damp Proofing

In concrete this involves adding products like SBR latex a Styrene Butadiene Copolymer Latex which is specially modified to be compatible with cement based mixes (ordinary Portland cement or high alumina cement). It may be incorporated into cementitious renders, screeds or patching mixes in order to improve adhesion and abrasion resistance. It can be used internally or externally and in areas of continuous or intermittent water contact.

Cavity Wall Construction

Is the construction of two walls approximately 75mm apart, held together by wall ties. The outer external wall takes the weathering keeping the internal wall dry.  Then the outer wall in times of dryer weather uses evaporation to disperse moisture from the cavity. A good air flow is a must in cavity wall construction.

Be Dri Damp Treatment Customer Service

Don’t be damp Be Dri call us today and let us help you with any ofDamp treatment customer service in Dorset Wiltshire Hampshire Somerset your damp proofing, woodworm treatments, wall tie replacement, repointing brickwork and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions.

Damp treatment in Bournemouth – Poole – Weymouth – Swanage – Dorchester – Blandford – Wareham – Wimborne – Shaftesbury –  Bridport – Christchurch – Dorset – Wiltshire – Hampshire – Somerset

Home Ventilation System 

Home Ventilation System solutions for you home, if you’re suffering from excessive moisture in your home with damp walls and ceilings in your bedrooms and kitchens or bathrooms. Then this is modern living not enough extraction fans to expel the humid air during the day.

Heat recovery systems

Extraction Fans

Inline Extraction Fans

Positive Pressure Vent’

Home Ventilation Systems & Domestic Fans

Home Ventilation System

Home Ventilation System will help new and old buildings that will require mechanical ventilation to maintain indoor air quality. A good Home Ventilation System will also help control moisture which can lead to mould growth and health problems in extreme cases.

The decision to use a Home Ventilation System is usually due to concerns that natural ventilation will not provide adequate air quality.

Controlling moisture with a Home Ventilation System can make your home more energy efficient and more comfortable to live in. Properly controlling moisture in your home will improve how effective your ability to stop drafts and improving insulation has been a Home Ventilation System should be part of your moisture control strategy.

Home Ventilation System Installation

Once Be Dri receive the go ahead installations are carried out speedily. Most installations can be completed within four hours. We use diamond tipped dust extract boring equipment to minimise discomfort and we always make good afterwards. All our installation engineers are fully trained in customer care and treat customers and tenants in their properties with courtesy and respect.

Home Ventilation System Removes Moisture

Modern everyday living adds extra moisture to the air within our homes and without extraction it just accumulates day by day. This is what black mould (Aspergillus Niger) and similar moulds thrive on as they require high levels of surface moisture.

To give you some idea as to how much extra water this could be, here are a few recognised figures for levels of moisture produced during a typical week.

2 people at home can produce = 3 pints – Washing dishes = 2 pints – A bath or shower = 6 pints

Bottled gas heater (8 hours use) = 4 pints – Drying clothes indoors = 6 pints – Cooking and use of a kettle = 9 pints

Causes of condensation

  1. Are you cooking with little or no extraction?
  2. Are you guilty of drying your wet clothes on radiators during the winter?
  3. Does your tumble dryer vent to the outside or just pumps steam back into the house?
  4. Do you have a fan in the bathroom for when you take a bath or shower?
  5. Is the high humidity during the day and the cooler night time temperatures causing all these problems to condensate in your home?

Home Ventilation System Survey

We all deserve fresh, clean air in our homes so let us help you improve or upgrade your current ventilation requirements. We are a mould and Home Ventilation System specialist company.

Home ventilation system surveyOur surveyors will help you choose the right fan for your rooms and property.

Call today to improve your homes air quality.

Home Ventilation system Customer Service

Don’t be damp Be Dri call us today and let us help you with any of your ventilation, condensation, damp proofing, woodworm Home ventilation system customer servicetreatments, wall tie replacement, repointing brickwork, and wet and dry rot issues.

It’s free to call and costs nothing to ask your questions about home ventilation systems.

Heat Recovery Systems

The Sentinel Kinetic range of heat recovery systems provide balanced ventilation while recovering up to 91% of the heat from discharged air. This combination of benefits and high efficiency means that draught-free ventilation is achieved at 10% of the cost of traditional ventilation systems.

Two easy to take out filters remove dust to ensure air quality is maintained continuously with this heat recovery system.

The compact heat recovery systems are easy to fit and feature four air connections to provide ventilation to kitchen, bathroom, toilet and living areas. It is also compatible for use with low resistance ducts and control settings allow constant air flow under all conditions.

Featuring EC/DC motors the Sentinel Kinetic heat recovery systems range are classed as ‘zero energy units’ and cost just a few pence a day to run.

Heat recovery systems provide a controlled way of ventilating a home while minimising energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside exhaust air to the fresh (but cold) outside supply air. In the summer, the inside air cools the warmer supply air to reduce cooling costs.

Heat Recovery Systems Special Features

  • Low energy EC/DC motor
  • Horizontal duct option for space saving installations
  • Right and left hand options
  • Suitable for use with low resistance ducting systems
  • Optional M5 Grade high performance filter
  • G3 Grade filtration
  • Digital settings and read out display
  • Self-diagnosis fault finding and reporting
  • CO2 and humidity sensor options
  • Summer bypass with night-time cooling algorithm

Heat Recovery Systems Benefits             


  • Extremely low running costs
  • Heat exchanger transfers 91% of heat
  • High efficiency performance at all times
  • Pollen filter on air inlet
  • Wireless remote control option
  • Frost protection system maintains performance in freezing conditions

General Information

  • Recognized in SAP PCDB
  • Output and input spigots are top mounted
  • Suitable for Ø125mm connecting ducts
  • 230V power cable supplied as standard
  • Low voltage control connection supplied as standard
  • Multiple switching options
  • Digital controller for simple and accurate commissioning

Extraction Fans

The SensaFan A25 extraction fan range is a fully automatic 100mm (4″) safety extra low voltage axial fan for wall, ceiling or window applications in Zone 1. The energy efficient ball bearing 12V DC motor requires 2 watts of power when operating.  This extraction fan unit is supplied with a fan remote humidity sensor & transformer.

The Dynamic Humidity sensor within this extraction fan is designed to operate when any rapid increase in the humidity is sensed. When the water vapour has been extracted and the room returns to the previous humidity level, the Dynamic Controller will switch the fan off boost back to the pre-set trickle rate.


  • Extract rate 90m3 per hour (25 ltrs/sec)
  • SELV extraction fan unit can be positioned in Zone 1 or 2
  • Transformer/Humidity sensor unit must be positioned outside Zone 2
  • Lower energy cost for tenant in keeping with Government Directive regarding energy efficient electrical appliances in Social Housing
  • 5 Year Guarantee

In-line Extraction flow fans


In-line mixed flow fans are designed for use in longer duct runs. Two standard sizes of in-line fans are generally used for kitchens, bathrooms and other appropriate applications.

Installation is straight forward and the fans include a mounting bracket.

A complete range of ducting, grilles and accessories is available.

Larger in-line fans are also available.

Positive Pressure Ventilation

Units designed for houses or flats

Positive Pressure ventilation systems allow better control of the air that enters the house than just using extractor fan ventilation systems do. By pressurising the house, this ventilation system minimises outdoor pollutants in the living space and prevent back drafting of combustion gases from fireplaces and appliances. The unit also allows outdoor air introduced into the house to be filtered to remove pollen and dust or dehumidified to provide humidity control.

Positive Pressure ventilation Description

The unit gently operates in the background, pushing out stale humid air and replacing it with fresh filtered air from outside. Located in the loft, Air+ Positive Pressure ventilation draws fresh air into the loft cavity where it is filtered and warmed before being gently added into the habitable areas of the house. Positive Pressure ventilation is proven to reduce condensation and mould as well as dangerous levels of radon in specific areas of the UK.

Air+ Positive Pressure ventilation is supplied with an energy efficient preheater to temper incoming air. Designed to stop heat loss in the duct, the unit increases input air temperature by up to four degrees vs other traditional Positive Pressure ventilation available. Easy fix anti-vibration base and hanging kit supplied as standard.

Integral dynamic controls allow for bespoke installation set up as well as data recall showing running conditions and unit performance.

High grade G4 or F7 filters offer industry leading levels of filtration. Filter efficiency is also displayed via the front display.

The new low profile diffuser with sound cancelling technology can be cleaned easily and directs air away from fire alarms and walls. Models are available for condensation & mould or radon control.

Positive Pressure ventilation Special Features

Energy efficiency – consumes as low as 2.2 Watts

Electronic feedback to the motor ensures constant flow rate

DC motor for quiet operation

Diffusers designed to minimize draughts

Preheat facility as standard

10 preset air speeds

Adjustable heater operational point between 5-20°C

Blocked filter indication

Unit can be fitted to joist using the easy fix anti-vibration base or hung from rafters in the loft.

I would like to thank Bed Dri for remedying our damp issue. Simply clearing cavity and adding an airbrick has resolved it. Other companies were suggesting expensive and complicated treatments when simply ensuing air flow was the issue.
Simon Howes
High Street, Swanage.

What is the best Damp Treatment?

Alongside non permeable barriers and chemical treatments, often older house suffer with damp due to modern building improvements as well as failure of DPCs and pointing. Often its best keep the property water tight but maintain ventilation and airflow by clearing blocked cavities and ensuring proper airflow rather than masking a problem with barriers of chemical treatments.

Damp Survey

Click to our survey pageTo measure these effects damp companies use damp meters little yellow electronic devices with two little prongs for measuring damp.

The problem with these meters is that they measure all damp rising damp, penetrating damp, condensation and hygroscopic salts they don’t differentiate between them. So when it bleeps really loud or goes really red only an experienced surveyor can Interpret its readings and diagnose the property fault behind that reading.

These meters are useful in detecting the area the damp is coming from and at what level. And how its spreading in your property so a good surveyor will use the device as a guide because the device isn’t telling you what damp you have or why you have it.

That’s why you need some who works with Victorian and Edwardian houses because they are enthusiastic and passionate about the work they do. And the way that it should be carried out to preserve these period properties and their common faults.

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Swanage – Wareham – Bridport – Christchurch – Wimborne

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