We recently bought an 18 yr.-old house with lap cedar siding. The siding has been painted 2-3 times previously. Powerwashing is bringing off large flakes of paint with a thin coat of wood on the back side of the flakes. Any idea as to cause? What to do in repriming and repainting?
What you have is the wood delaminating and coming off with the paint. You will need to sand those areas to remove the flaking wood and paint. There is a product called PEEL STOP from Zinsser that will seal and hold down those loose wood fibers and the edges of the loose paint as well. After you apply the PEEL STOP you can apply the acrylic finish paint of you choice.