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.
This depends on what type of roof panels you are trying to install. In general, you need to remove all of the nails and panels from the section that your are replacing. You then place roofing felt on the roof, making sure to nail it down. The panels go over the felt. Install them from left to right. http://www.ehow.com/how-does_4778280_installing-tin-roof-panels.html
You tear the old roof off with one of those shovel looking thing that have teeth on the end. Remove the old felt paper and the nails and chingles. Then inspect the decking. Replace any decking that is rotten. Then put down new felt and flashing and replace shingles. Good luck.
Yes, If the roof has felt down it will make no difference. the first warm day it will all dry out.
You can use a stapler to attach felt to your shed roof, but it may not last as long.
Roof water resistance is your roof's resistance to rain where waterproof asphalt felt is the actual waterproof material.
Paper the whole roof!
Every roof will be different depending on the size of the roof, the materials needed , labor and if the house is one or two story. A few materials that you will need to check pricing for is felt, different types of shingles, nails, flashing, drip edge, pipe jacks, and decking. You can call a local supplier with those details and they will be able to give you a ball park figure.
30# felt is thicker..... Better?
Roofing paper, also known as roofing felt or tar paper, is typically made from a blend of cellulose fibers and bitumen (a petroleum-based material). These materials provide the paper with strength, flexibility, and waterproofing properties to protect the roof decking and interior of the building from moisture infiltration.
It protects the roof sheathing from moisture.
That depends. If this is a shingle or "steep slope" roof system, one layer of felt lapped 4" would be sufficient. A typical roll of #30 felt covers 200 sf.
I felt insensate after falling from the roof.