We have a decorative panel comprising four pieces of wood placed into a design shape framing the first floor windows. One piece of timber has fallen off. This is happened twice before, once it seemed to just fall off, I had it put back on, but we recently had the house pressure washed, he hit the timber and it again fell off. I have the piece and would like to have it replaced again, but I want to ensure that it stays in place. My question is what is the best way to do this? Can you recommend a very strong adhesive? 