Hi ..new to forum and have a question. We built our icf home ourselves but due to circumstances beyond our control its taken nearly 3 years. We are now at the point of glazing and rendering but are heading into unpredictable winter weather. Have had a quote to render at £20 sq metre (is this about right). Will the icf stand up to another winter - when I place my hand on it there is a thin layer of dirt which I have been advised wiki have to be gently pressure washed off before the render can go on. Financially it would help to postpone till next year and do more inside. Any advice would be appreciated. Anisia

I'm not sure what 'render' is- I'm assuming stucco? Weathered ICF would need to be cleaned before anything like that is applied. My contractor said the he uses a steel broom to scarify the surface for stucco, even on new ICF.