I’m putting a second 3-tab shingle roof over an existing 28-year-old 3-tab shingle roof. Since I’ve always torn off the old roof previously, I have a couple of questions that you wizards may know the answers to:
1. Should I put Ice and Water Shield over the old shingles (along the drip edges, gable ends, and valleys), or do I just count on the integrity of the old roofing (it is NOT leaking now)? I’m doing fully-woven valleys: shingles run through the valley from both sides, alternately, so that they overlap in the valley.
2. I have crickets up-slope from the backs of chimneys. Of course, at the lower edge, these are woven into the existing layer of shingles. How do you cope with this: new cricket over top of the old one? something easier?
My BI is not at all helpful with questions like this: “Read the code” he says. I’m not finding any help in the code for this situation.
Thanks for any help
Bob Chapman, in NJ
Replies
Before even starting to answer, I would need to know what part of the country you are in, how steep the roof is, and whether the existing shingles have started to curl, and what material the crickets and step flashing is made of....???????
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. . . and why you're not doing a tear-off ?
Greg
. . . and why you're not doing a tear-off ?
Don;t want the effort of getting rid of the waste. I'm happy to let the next person do that.
Bob
The Grace is a toss up.
Pull out the copper flashings and set on just this top roof.
Thanks, Slateman
Bob
Before even starting to answer, I would need to know what part of the country you are in, how steep the roof is, and whether the existing shingles have started to curl, and what material the crickets and step flashing is made of....???????
New Jersey
9 in 12
no curling
copper flashings all around, including cricket
OK, given the steep pitch, no known leaking, and a mild climate, the I&*W is not really necessary if you have a decent insulation and venting program. Ever see any ice damning?
I would possibly line the valleys with it or with roll roofing.
What I do for roof-overs is to use a hook bladed utility knife and remove exiting shingle where they tie into the step flashing and cricket if it is good metal, which it sounds like yours is, and then weave the new shingles into the same steps. Take care there in case they nailed thru.
Reason I asked all that is some jobs are not worth roofing over. Duck anyways. Some guys consider ANY roof-over a hack job. The manufacturers will void a warrantee done that way, but it is common in a lot of places if done carefully
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Piffin-
Thanks for your advice.
Bob