Hi, I have a crack in the render running between an upstairs and downstairs window.It is only small has been there for years and was filled once by a family member who painted the outside. Is this a job for a builder or would a qualified painter and decorator do this. We have some damp at the bottom of the wall under the window which I think may be in part because of this>
This is such a simple job but everybody likes to make it complicated !
It is a movement crack and it will continue to flex as the building contracts and expands in varying temperatures and humidity .
The trick is to NOT chop out the crack but fill it with acrylic paste ( in tube) . If the crack is too small to fill , put the acrylic sealer over the crack and rub it in .
Paint the area of the crack and whilst the paint is still wet , cover with a fibreglass tape ( B&Q have it , I think it's called wall crack repair tape . Allow that to dry before applying a coat of paint to seal it .
This will allow the crack to move but never open again .