Replies

1. 
   mitch | May 06, 2004 04:03pm | #1

   you might want to check local codes but roll roofing is so lightweight on a per sq ft basis (90lbs/100sq ft vs about 200-240lbs for 3-tabs) that additional layers are almost always allowable.  given that it results in more coverage, in most situations it's even desirable.  so long as the existing surface is flat and smooth, i'd leave it on.

   m

1. 
   wolfman | May 06, 2004 04:35pm | #2

   Thanks Mitch. When the leak first happened I went up and sealed all the joints. The roofing is pretty flat, Its just worn. I'm not convinced the leak is right at he skylight, I've been up there twice. I think its leaking higher up, running down,  and coming out at the skylight.

1. 
   CapnMac | May 06, 2004 04:51pm | #3

   I think its leaking higher up, running down,  and coming out at the skylight

   You have hit upon my least favorite part of "find the roof leak."

   Hanging out in the attic everytime it rains is more than a bit impractical (and my attic gets to the mid-90s now that it's May here in Texas). 

   Is the roof deck solid, or is is skip sheathing?  With skip sheathing, sometimes, you can put a bead of silicone as a 'drip edge' "uphill" of a suspect roof feature.  (Be sure to put a pan or plastic wash tub under it.)  If the water is getting in up high, it will drip i nthe tub, instead of down around the skylight surround.

   If there's a transition from opne pitch to another, that's another place to look.  I did a tear out of a porch-made-into-a-room where the porch roof had been given a flashing (6" wide) on top of the roof felt (the porch roof paper lapped over the flashing for reasons only the yabo who did it probably couldn't explain today, x decades later . . . )  Occupational hazard of my occupation not being around (sorry Bubba)

1. 
   wolfman | May 06, 2004 05:03pm | #4

   The roof in question is over a one story addition that was built some years back before I owned the proprty. There is no attic space for me to get into, the only space between the roof and the ceiling being the joists. I think I'm going to bite the bullet and have another layer of shingles put on.

   Bob

2. 
   BossHog | May 06, 2004 05:08pm | #5

   "I have a flat section of roof with a rolled alphalt shingle on it."

   Back the roofing truck up a minute. You can't use rolled roofing on a flat roof, can you ???

   Or is the roof not really flat?

   Never appeal to a man's better nature. He may not have one. Invoking his self-interest gives you more leverage.

1. 
   wolfman | May 06, 2004 06:06pm | #6

   You're right Boss Hog, the roof is not flat, I called it flat but it does have a slight pitch. Very slight. If I had to guess, maybe 1 on 10-15.

1. 
   Piffin | May 07, 2004 03:06am | #7

   yes you can double or triple the roll roofing. prferable to do so.

   But I always strip to the flashing so that seal is right if I roof over. No telling what goes on there, but sometimes you can find a water sign that leads you to the actual source of the leak, if yuou can read the signs. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   JohnSprung | May 07, 2004 03:28am | #8

   Here in LA, code lets you go up to three layers.  When the third one is shot, you have to tear off and start fresh.

   -- J.S.

4. 
   MojoMan | May 07, 2004 05:05am | #9

   I'm pretty sure the preferred modern approach to a situation like this would be a rubber roof. Strip all the existing roofing, repair any rot, put down fiberboard underlayment and then the rubber. This will cost quite a bit more than another layer of rolled asphalt, but the superior longevity may be worth it.

   Al Mollitor, Sharon MA