If Roof decking is wet is it right to install felt?

Answer 1

I have roofed many houses and yes roofed in light rain. The felt will soak up water in the decking and the heat of comp shingles will dry out the felt. It makes for a dangerous job if your on a high pitched roof. When the felt gets wet it will crinkle up and not lay flat which may not be noticed if you have a thick comp shingle (30 year+). I've tried covering the roof to protect from rain with plastic or tarps, but it always seems to be waisted work. Tarps blow off, holes in plastic from laying boards down which causes leaks. I prefer to put my work to get the job completed. I have never hear of mold in decking from roofing in wet conditions. I have removed roofs that had rotten decking due to low pitch and surrounded by trees which did not allow the roof to dry out after rains. The rotten decking was only in certain areas of the roof and only less than 10% of the decking. I wouldn't say the 10% replacement was due to roofing in wet conditions. That is my experiences, hope that helps.

Answer 2

If installing felt onto a deck, it should be completely dry and free of debris. If the felt is installed while the deck is wet, this may lead to the trapping of moisture under the felt which could lead to premature decay of the wood, as well as mold.