i would strongly advise you against using k-rend and webber both of these products are very troublesome with cracks, discolouration, going green i could go on and on! I'm a plasterer myself and i have been using monocouche for years and have came across all the problems. These are the most commonly used by greedy plasterers that are not concerned about the job when they walk out the gate. These are the cheapest materials that's why they will tell you you they are the best, but only the best for their pockets. I would strongly recommend Parex. I've been using it for years all over ireland even on the west coast where the weather conditions are extreme. Parex is the only true one coat render if you carefully read the technical spec. for these plasters you will find they actually need to be applied in two coats!! Hence all the problems, improper apllication by inexperienced plasterers and builders. Parex is the only true one coat render it's been used for years all over Europe these other plasters are made in Ireland. Hope i've been a help in time if you want i can send you photos of jobs done withe parex . by the way i don't sell this product or am not associated in any way with the suppliers i just use it and know it's good!!