NC Residential Roofing Code

[TheMoody1]

Anybody familiar with the code for a re-roof? The guy told me I have two layers of asphalt shingles. He said he would tear off one layer and put the new shingles over the other old layer. Doesn't sound right to me.

[CVAPP]

Sorry, I don't know what the code is, but my concern would be not replacing any sheathing that may have deteriorated over the period of time the two sets of shingles have been there. Especially if it has had leaks. It will however cost more to do it from the deck up because there will be more labor and hauling/landfill expenses from tearing off the older layer. Also, if sheathing needs to be replaced that will add to the project cost as well.
In my experience get several estimates and see what others say. Good luck with it.

[moonshine]

If they’re taking 1 layer off, why not both? Since this is a once, maybe twice in a life expenditure, assuming you stay in the same house, I’d want it completely redone. Tear off everything down to the plywood to make sure there’s no rotten sheathing that needs to be replaced. New ply installation should run around $50 a sheet.

Go back with new: drip edge, flashing, vent boots, 30 lb felt and 30 year architectural shingles, not the 3 tab. Maybe add a ridge vent if you don’t currently have one.

[ASU Architect]

Chances are adding new shingles on top of old is going to void your warranty on the new ones. The advice in the previous post is much better than what your guy is telling you.

[asu66]

Anybody familiar with the code for a re-roof? The guy told me I have two layers of asphalt shingles. He said he would tear off one layer and put the new shingles over the other old layer. Doesn't sound right to me.

Typically, there's a state code that is your baseline and a local (city or county) code which can supersede the state code if it is more stringent in its requirements.

The "guy" who advised you to strip off the top layer and put new shingles on top of the "other old later" sounds like a good ol' boy who has never seen the code where you live. He might save you some money but you could end up with a nightmare if/when something goes wrong. Most reputable and licensed roofers will require that you remove both old layers before they will be able to activate the manufacturer's warranty. Been there recently and got the good ol' boy quotes and and the licensed contractor quotes. I chose the latter!

FWIW, here's the current NC state residential roofing code...

https://up.codes/viewer/north_carolina/ ... blies#R908

Something makes me think you're in SC. If you're anywhere in the coastal region, there will be a strict local code! Moonshine is singing from the right hymnal (above)...

[Appstrong]

I’d like to chime in also with the fact that the extra layer of shingles adds useless extra weight to your roof and reduces the life of your new shingles by approximately 50%. If it were mine I would remove both layers. It shouldn’t be that much extra labor to remove both layers considering you really cannot remove the top layer without inevitably damaging or removing some of the layer beneath to some extent.

[TheMoody1]

Something makes me think you're in SC. If you're anywhere in the coastal region, there will be a strict local code! Moonshine is singing from the right hymnal (above)...

Fortunate enough to have a house in NC too.

R908.3.1.1 Roof RE-Cover Not Allowed

A roof re-cover shall not be permitted where any of the following conditions occur:
Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
Where the existing roof covering is slate, clay, cement or asbestos-cement tile.
Where the existing roof has two or more applications of any type of roof covering.

[mountaineerman]

I am a NC general Contractor. The code is you are allowed up to two layers of Roofing. Tearing off one layer to install over another is about the most ridiculous thing I’ve ever heard. My advice tear both layers off install new synthetic underlayment and install the new shingles right. It may cost you another 1000$ but it will pay for itself in the long term.

[Mountaineers89]

I work in the commercial low slope industry. You should tear off down to the deck when you already have 2 roofs. Definitely go back with architectural shingles. I recommend ring shank nails too.

[CVAPP]

If they’re taking 1 layer off, why not both? Since this is a once, maybe twice in a life expenditure, assuming you stay in the same house, I’d want it completely redone. Tear off everything down to the plywood to make sure there’s no rotten sheathing that needs to be replaced. New ply installation should run around $50 a sheet.

Go back with new: drip edge, flashing, vent boots, 30 lb felt and 30 year architectural shingles, not the 3 tab. Maybe add a ridge vent if you don’t currently have one.

I think you are spot on. Go Apps!