I’ve got some questions about roll roofing.
Back in 1990 contractors installed roll roofing over three rooms, and in the past year it began to significantly fail. This past August I removed it all, and put down (stapled - big mistake!) No. 15 felt paper in anticipation of roll roofing. I thought felt paper could withstand the elements for at least a week, but as soon as rain hit it it warped and buckled beyond recognition, and all the staples tore through. Even after drying it was still uselessly deformed. Since I knew I had to tear it off and start again, one thing led to another, then some financial problems, and before I knew it autumn was upon me and I still hadn’t gotten it done.
Why am I posting this? Because now that I’m starting fresh, and with enough money to complete the task properly, I’d like some suggestions on what to use.
Here are some pictures of the roof from August:
The large sloped roof in photos 1 and 2 is the garage. I’m not quite sure how to do the valley, since the garage roof is already on. What you can’t see in that picture is an 18" wide piece of flashing that was nailed on in 1990. I slid the felt paper under the shingles as best I could, but from then on I don’t know what to do. Every book I read offers conflicting advice as to the best way to do a valley with roll roofing.
I’d appreciate it if someone could answer these questions:
Should I use that rubbery “ice and water shield” stuff along the eves and rakes? On the valley too?
Is there a specific brand or type of underlayment that works best? I read somewhere that the thicker felt might create problems by causing condensation.
How much overhang of felt should I leave off the eve? When I put the roll roofing down, how much should that overhang?
When laying down the felt, how much overlap should there be?
When laying down the roofing (double-coverage) how frequently should I nail, and how far from the top edge of the roll?
I’ve read that the starter strip should be cemented on - wouldn’t it be better to use the “self-adhesive” ice and water shield instead?
In my mind, once the first course is down, I’d nail the uncoated portion. Then I’d prepare a second course that would overlap that uncoated portion. Does the overlap need to be cemented? I assumed so, but I was told only vertical seams needed to be cemented. Which way is correct?
I know each course has to cover the uncoated portion of the course below it (at least 19"), but how much should I overlap? 19.5"? 20"?
Thanks for any advice!