Re-roofing used to be pretty straight forward with 3-tab shingles. The standard practice was that you could install a new layer of singles directly over the old layer during a re-roof. Most people would limit this practice to a total of two layers of shingles. Any more than that and you’d have to tear off the old shingles before installing a new layer.
Today the question of installing architectural shingles over an older layer of architectural shingles is a bit more complicated and one that doesn’t seem to have 100% consensus.
The answer to the question starts with the drastic difference between an architectural (laminated) shingle and an old school 3-tab shingle. Three tab shingles are a constant thickness while architectural shingles have multiple layers that create an uneven surface. If you look at the picture above you can see the difference.
The quick answer is yes you can re-roof architectural shingles over existing architectural shingles (however you must check with the shingle manufacturer as well). Having said that it will be nearly impossible to get a good looking quality installation. As you can see from the photo the architectural shingles will have bumps created by the old shingles which will keep the new shingles from looking flat and smooth.
The professional answer is no you should not attempt to re-roof architectural shingles over existing architectural shingles. I wouldn’t do it to my home and I certainly would not recommend it to a client. The reality is it would be nearly impossible to get a good look and frankly keep the shingles down flat on the roof and prevent wind damage. I also think that many shingle companies probably prohibit it as well.
For a more professional installation I would highly recommend tearing off the old shingles before installing the new ones. Frankly I’ve yet to see an architectural shingle that needed to be replaced except ones damaged by weather like hail.
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Todd, I was JUST thinking about this question. Glad to know the pro answer.
Please, please, please, get references from satisfied customers and check that they actually had work done and are not "professional" reference "people. Installed improperly architectural shingles are a true nightmare.
A customer had hired an "experienced crew" to re roof her home, the work was actually done by a crew who had never installed these types of shingles.
Standard shingles are pretty straight forward for installation but if architectural shingles are installed incorrectly and leak the only recourse is strip and re roof correctly. The roofing company owner tried every excuse in the book, "It's condensation, they will seal when the summer sun hits them" etc, then he disappeared.
so beware, they look nice when installed correctly but no give if they leak.
What if my roofer puts ice and snow shield over the whole roof? I have a very steep small townhouse roof in the DC area. And have been suffering leak problems. The idea of no leaks is very appealing and his cost very reasonable. But I worry about not being able to remove the tiles. He said just tile over them. That didn't sound too good.
Not sure I understand your question. Ice and water shield would NEVER be put over existing shingles.
HI..If I were to reroof over 3 tab with shingles, should I run a dehumidifier in the attic to draw moisture out?
I had architectural shingles installed in 2008 and now
It’s leaking from one end to the other. My insurance
Company will not replace because they were installed
Incorrectly
I have an experienced roofer over 30 years experience telling me his company
Can install architectural shingles over the existing
Help !
you can...but i wouldn't...i'd remove the old first
in south fl architectural shingles do wear out. i installed timber line 25 years ago. . and need to replace. main reason dirt . ,mildew . if you have trees covering roof trim them back. also where they meet flat decks they get hard and crack from movement. and of course hurricanes winds will cause damage . having said this. 20 years with no problems 3 hurricanes . cat1 and cat 2 . and only lost 5 cap shingles . very good martial to use..i also only have 1 12in 2 1/2 in pitch. was told they dont work so well with low pitch . but ppl i seen use 3 tabe . dont hold up to strong wind at all. i am not roofer . but have installed a few.
I have a regular style 3tab roof and it has discolored, i have no leaks and want to reroof with laminated architectural shingle is this possible?
We stripped our 25 yr old roof and are halfway done installing architectural shingles. My wife hates the color. She wants to start over. That would be cheaper than a divorce, but are there any other good solutions?
Frank Gambardella:
Correct installation of venting is crucial. It runs on convection, no power needed. Since you are asking about running a dehumidifier in the attic, my guess is you already have moisture issue. Next guess is you have roof decking to replace. Tear-off might be mandatory - make sure your contractor knows venting - NARI and/or NRCA member might be a good place to start.
I had an architectural shingle installed over an existing architectural shingle that was old. The roofer shot nails through the new shingle that properties through the soffit and are exposed and damaged some of the wood under the soffit. The roofer claims this is necessary when installing shingles over existing shingles to secure them from wind. Is this true?
Total BS :)