Cracks in Render
Cracks in render allowing damp in walls can happen if the outside walls have a defective render stuck onto them (or not stuck too good)
If you have cracks in your render may be asking yourself or googling how to stop-cure damp in my walls
What can be done to stop or repair cracks in render
Can my walls be repaired if so, how? What’s the best render to stop cracks in my render?
If you have a wall that is exposed to the elements (South/Westerly) and subject to wind-driven, moisture can get through the render and into the home. Water penetration can be more problematic if the walls are solid. Sometimes damp in render can be caused by the render being too absorbent. Damp cracked render may be caused by the render mix not being of the correct type with incorrect sands and the ratios of ingredients
Render can come in all forms and shapes, such as renders that are made on site in small cement mixers or mixed by paddle mixer or hand. Render made in a cement mixer render usually consists of sand and cement and sometimes admixtures such as PVA, Latex, frost proofers etc. If the wrong sand is used then you can get problems, cracks occur in the render and allow water ingress. Also, adhesion problems may cause rendering to fail, such as the surface under the render not being prepared correctly. If the walls that have render applied to them have been painted then you will not get proper adhesion.
Render relies on both mechanical and suction factors. If the render is not strong enough (if soft ungraded sand has been used) then the render will be prone to cracking.
Cracks allow water inside the wall itself. If the mortar mix is to prevent damp in the render, then it needs to be mixed correctly with the correct surface preparation. During our years of surveying, All4Walls have seen many renders fail allowing damp inside the home. Made in the bag renders can be a good idea as they are ready-made a bit like a cake mix. The correct sand with the correct amounts of other ingredients, all you need to do is to add water. Chopped fiber added to the base coat for deep areas can also be useful in limiting the dangers of slumping and cracking in the render. Also, nylon mesh cloth can be embedded between render coats, this virtually eliminates the risk of cracking in render and the subsequent damp problems with a defective cracked render finish. Before you get the walls of your home rendered or repaired why not arrange a survey.
We can specify the correct preparation and the correct render material be it lime base Dor polymer cement make sure it’s right for your home and will last the test of time to contact us.
See our other section about the best render to use on solid walls or contact us for more information