05 Dec Roofing Tips: "Roofing Over" vs. New Roof

Today, on In the House, Jim talks to a show listener with an aging roof. Is it better to roof over – lay new shingles over the existing ones – or tear it all off and replace the entire roof?
Jim: Good morning. Keith in Amelia Island has a question about his aging architectural shingle roof. How are you doing, Keith?  How can we help you today?
Keith: I am doing well. I would like to know if just recovering my roof is more cost effective in the long run, or if it’s best just to go ahead and strip off the old shingles at this point. They’re 23 years old, and there’s some wear. Some of the granules are missing in places, but the roof is overall sound.
Jim: Right, so no leaks that you can spot or anything like that?
Keith: Right. All leaks that occurred over the years were addressed. There were some flashing issues, but overall, integrity is sound. I guess I’m looking at it from a cost perspective.
Jim: It is legal; you are allowed to shingle over a roof in the state of Florida. In my opinion, it’s one of those things that falls under “everything is permissible, but not everything is beneficial”. It is permissible; there are codes that allow it, but I personally just don’t think it’s worth it – especially at the age of your roof. I know you said it’s good and sound, but if there’s any wood rot around any of the pipe jacks or any of the protrusions, that problem’s still going to be there when your cover it up.
In my opinion, it’s definitely better to tear it off all the way down to the roof decking, because you also then re-nail your roof deck, so your roof decking will be nailed according to current code. This also could possibly – and this is no guarantee of course – but it could possibly improve your wind mitigation status. It’s one of those things where you count the cost, and it’s just not worth the benefits that you get or the little bit of savings that you get. These guys that tear off those roofs do it every day; they remove and replace so fast it’s really not a large part of the expense.
Keith: Okay.
Jim: Plus, around all the penetrations you’re supposed to improve the underlayment and those types of things. At Universal Roof, we do peel and stick around the penetrations, the pipe jacks and the goosenecks and any off ridge vent that you may have. We’re going to improve the waterproofing around those, so if you end up having to tear off the deck to do that, then you can’t really do that. One other issue that would be a down the road type of issue is that if you ever have to do a repair on it in the future, it is very, very difficult to tie back into a shingle over-roof.
Keith: Okay. You’ve made it pretty clear.
Jim: There are some products, some metal roof products, that they have specific specs because it’s basically a whole new roof system. Some metal roofs, they allow it, but even then, I’m like, “Let’s just tear it off and do it absolutely the best possible way we can.”
Keith: Yeah, okay. Thanks very much. I appreciate it.
Jim: Thanks so much for calling, Keith. That’s a question, a lot of people ask; we pretty much always have the same advice. It is allowable, but it is not necessarily the best possible solution for the reasons that I listed, and there are other reasons, as well. Even things like drip edge, changing the drip edge. New code on drip edge requires different amounts of overlap and different gauge than it did 20 years ago in the state of Florida. Part of the benefit of changing a roof is bringing a roof up to current code. Obviously, if you’re roofing over, you really can’t do that as well. It’s always one of those things that people consider, but I just don’t think the benefits are enough to outweigh the potential detriment.
Not surprisingly, Jared is in agreement with Jim on this! His opinion, Coming Soon on the same matter in Roofing Over vs. New Roof, Part II.
Read more about roof repair and replacement on our website. Listen Saturday mornings to “In the House”. Get more Home Tips and show info at the In the House website. For a free inspection and estimate on your next Home Improvement Project, visit Universal Roof & Contracting or call now. Orlando: 407-295-7403 Jacksonville: 904-647-3907.