Anti-Crack Lime Render
Specified lime based render old chapel outskirts of Leeds
Although lime renders are less prone to cracking than cement renders, the lime base coats were mesh reinforced with nylon scrim.
Originally a Victorian Methodist chapel. The building was converted to a bungalow in the 1960s. Unfortunately, a lot of the original internal features and the exterior facade detail was lost during the conversion. The Walls are a solid wall build( three bricks thick). The 1960s renovation was beginning to show signs of fatigue and deterioration. The old cement render was causing damp walls within the building.
As is often the case with old solid walls, the cement based render turned out to be a bad decision. We often get clients asking “do cement renders breathe” or “are cement renders good for solid walls”
Solid walls especially those built on the ground with no damp proof membrane nearly always have a higher moisture content than modern-built houses. Cement or concrete renders stop walls from breathing, in other words, they trap damp in the walls. Renders made from cement are also prone to cracking, (especially when used with the wrong sand). Cracks in render, however, small are the beginning of the end for any render finish. Damp gets inside and behind the render, frost (freeze-thaw) then damages the render allowing more damp inside, and further damage.
Lime render is softer then concrete render, it is much less prone to cracking, we add even more protection against cracks in the render by adding a special nylon scrim mesh between render coats. Out lime renders are usually specified at a minimum thickness of 15mm
The owners of the house, planned for many years to renovate the exterior, finally, in 2018, they embarked upon some building work to include a balcony, new kitchen and windows. All4walls carried out the survey, we specified and project managed the exterior facade work. Avant Coating of Leeds were the main contractors.
Following our recommendations, after careful consideration, the client decided on a rough cast lime render finish.
The textured finish weathers better than smooth surfaces. Wind-driven rain is slowed down and pushed across the surface which has a bigger surface area.
A roughcast finish is more in keeping with older buildings. The Parex lime render used is through coloured NHL lime render, (self-coloured pigmented ) and requires no painting.
See out other pages for more information on Lime render