Tear off or shingle over old shingles

I am getting bids on reroofing an 8/12, 200 square assisted living because the 6 year old IKO 3 tabs are cracking and did not seal well. They are pretty flat and it is my amateur opinion that going over the top of them with a heavy architectural shingle would be less expensive and of equal quality. But I am only a dangerous amateur so I would like the opinion and reasoning of some pros without a financial stake in the project.

some pics of the IKO’s just for fun

Tear them off, they will continue to deteriorate under the new shingles.

That particular shingle is a bad product and should be avoided.

some of those cracks might be caused by plywood movement…make sure all the joints have an 1/8" gap for expansion. But then agan…maybe not :?

I do a lot of nail overs but this one sends up red flags, I haven’t seen many roofs like this and we usually tear them off when the manufactuer and warranty is involved.

Bottom line, you either pay now or someone will pay more later for a 2-layer tear off. If the shingles weren’t splitting and /or cracking , I would say yes on a nail over. I don’t think I would put my name on that roof without tearing it off to the deck, inspecting the decking , and checking for proper ventilation.

allrite go ahead and but n run another layer of
3tab un there if you must.
make sure you use 1.5" roofing nails.



Do not go over IKO’s.

Maybe you can fix what is bad and get another year or two out of the shingles. This way you can budget for a tear off.

I would consider pursuing a manufacturer’s defect claim on this matter. There’s no way that shingles should be cracking and splitting like that.

It is probably wise to spend a little bit of money for a structural engineer or someone who is independent and an expert in roofing. Normally, an engineer’s opinion will hold more weight.

They should provide to you a written expert’s opinion report.

They can tell you then whether or not the roof was installed properly, whether it is properly vented, whether there is a performance issue in the materials.

Then, you’ll be in a much better position to determine if there is someone (manufacturer, installer … etc) to pursue.

I will say this, going over this roof is a very bad idea. It will curl up and it will telegraph thru to the new layer. I am never a big fan of a recover. They just dont last as long as they used to. I have done in my career in roofing 3 recovers. 2 i had no coice or i did not get the job no matter how i pleaded with them to not have it done. The other she was 90 years old and would never see the time frame of the roof. Nice lady, rest in peace mrs. harvey.