Lime renders were traditionally applied to give protection to walls built of poor quality rubble stone or porous brick or to walls in exposed locations facing driving winds. They help by acting like a sponge, absorbing rainfall then allowing it to evaporate rather than soak into the wall. Most cottages and houses built of rubble stone would have been rendered originally, and they tend to suffer from penetrating damp if the lime render is removed or replaced with a cement rich render.
Renders were always originally lime based, keeping the stone and timber dry beneath and allowing the walls to ‘breathe’. Unfortunately, in recent years, it has become common practice to use impervious cement rich renders. Because such renders are inflexible and non-porous unlike the traditional walling materials they cover, cracking occurs in the rendered surface, allowing water to penetrate and become trapped, causing stone, timber and brickwork to remain damp and begin to decay.
At Devon Render Systems we use a machine to pump on breathable lime renders meaning a faster turn around on products.
We have used baumit’s multi purpose renders which offer a highly versatile solution on renovation projects which can have mesh incorporated to give strength to the system.
Decorative finishes can also be used with acrylic & silicone texture grains available from 1.5-3mm.