the cracking ingredients
Render coatings can be made up of different materials – there is cement render, cement lime render, and acrylic render. No matter how it is formulated (usually a ratio including sand, lime, cement and water), cement render is highly alkaline and extremely rigid. After it is mixed and applied to the building it has to be left for 28 days to cure which allows the alkaline to stabilise before it is painted. After being painted, the render is usually exposed to extreme variations in temperature which causes it to expand and contract. This ongoing stress on an inflexible product causes the render to crack. These cracks appear first as hairline cracks and are more obvious when the render is wet.
While hairline cracking can be patched up with different products (see image below), this does not deal with the underlying problem; it only provides a temporary solution. The recommended action – and unfortunately the most expensive – is to demolish any affected areas and prepare to re-render them. Cracks can allow water penetration which instantly worsens any situation and will only lead to other costly issues.
Other Render Issues
In addition to cracking, other issues concerning render include:
- Damp penetration in the walls
- Peeling masonry paint
- Mismatched bricks
- Poor spray coating and render wall coatings resulting in drummy render
These sorts of issues are what we get called out to fix regularly. As always, no matter how long it takes, we will go to the root of the problem before repairing your render – no matter what it is made of – good as new.