Repointing houses and brickwork why we do need it and why it is so important to get the repointing replacement mix right.
The pointing is the mortar around the brick and it comes in different colours and has different thickness called bed joints (Horizontal) and perpendicular joints (Vertical).
The mortar joints do several things one, mortar joints are the outer face of the mortar bed which binds together bricks / stone it holds your house together. Secondly, it’s the joints and beds that allow moisture to evaporate from the face of the wall instead of the face of the brick / stone which leads to spalling.
Repointing is the process of renewing the pointing, which is the external part of mortar joints, in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units, usually in bricks, allowing the undesirable entrance of water.
Water entering through these voids can cause significant damage through frost weathering and from salt dissolution and deposition. Repointing is also called pointing, or pointing up, although these terms more properly refer to the finishing step in new construction.
Repointing a House
What Victorian and Edwardian properties have in common is that many people will condemn old lime mortar too quickly for being too soft or powdery because they compare it to a hard modern cement pointing. But sand and lime pointing is supposed to degrade over time it’s the sacrificial part of the wall.
The original viewpoint was that pointing should act as a channel so that moisture could evaporate out of the walls. Pointing was always going wash out over the next 50 – 100 years caused by weathering.
So it was better for the pointing to slowly erode and replace it decades later than bricks or stone which could not be easily replaced.
It would be a mistake to think that repointing an old house constructed in brick or stone with a strong cement mortar will be better and last longer.What this actually does is to cause these materials to crumble on the face side of the brick or stone.
Incorrect Pointing Material
When repairs started to be made in very hard cement because people didn’t understand old buildings problems started to appear, it has the effect of trapping moisture in the wall.
Mortar mixes should be slightly weaker than the surrounding material other wise spalling brick or stone work is a common site. Sand and lime is the appropriate material to replace old mortar.
Spalling is when moisture is trapped inside the wall because the hard cement pointing is keeping it there. To escape it forces its way through the next softest material which is your face brick or stone work and during times of hard frosts and freezing conditions blows the material apart.
Spalling or eroded bricks is a common sight today this is because people do not understand the long term problems caused by replacing old sand and lime with dense cement mortar or Portland cement. To stop the mortar eroding inexperienced builders have started to replace the sand and lime with a product that doesn’t breath and isn’t flexible.
In the long run this cement replacement will cause excessive spalling, increase the cracking of bricks on your external walls and will trap damp in the walls which will cause other problems.
The main problem and a very serious consideration are by not being able to expel the trapped moisture and this will affect your wall ties. Which if you have a galvanised wall ties and most old Victorian early
Edwardian properties do then this will cause them to start rusting much faster under the brick, if they weren’t showing signs of wear after 100 years anyway.
At Bedri we can help undo any old damaged caused by using the wrong materials by inexperienced builders. We can also replace any pointing which is now showing wear and affecting the out brickwork.
We can offer you different sands and colours which when the house is cleaned down and the pointing finished will make your property look new again.
Dustless Extraction System
Our removal technique can remove the old mortar using our Dustless Extraction System. We can also replace any old damaged bricks with reclaimed period brick.
Our Dustless Extraction System will capture over 95 % of the dust which even on a small house can be over 18 bags 20kg with over 300kg of extracted loose material. That’s a lot of dust that won’t be all over your cars and neighbours property or drift back into your home if you are asthmatic.
House Pointing Survey
If you feel that your house is suffering from erosion the process of eroding or being eroded by wind, water, or other natural agents. And your brickwork is looking extremely weathered and tired then you need an experienced surveyor.
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.
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.