Roofing over ceder after tearing up 2 layers of shingles?

a customer wants me to tear off two layers of asphalt and lay shingles over the old ceder. it is in great shape but will this be ok? i told her we need to ply wood and she said she will not. if you can do this do you put under layment down or not?

in my area it is against code. cedar must come off.

Walk away.


You will not be able to shingle over the cedar shingles again.

Once you pull off 2 layers of shingles, they will be like toothpicks. All the holes from the nails will leave the cedar very weak. Then you will put a whole new set of holes in it.

I would not do it. Walk away.

im down in N.C. but lived in Rhode Island.while roofing there it was a code to tear off cedar and Re-sheath.Here in NC,shakes are found in areas.same code apllies.Tear-off and Re-sheath.
appearence would definately look better and and sealantadhesion would be better without the humptie dumps underneath shingle application.

thanks for the help. thats what i thought. if i get this job i will be re-sheathing it.

now that i am thinking about it. if you are going to re-roof over ceder for the first time do you use under layment or not. do any of you re-roof over ceder these days or not?

in NY state i havent seen anyone roof over cedar in my career…but it was a very common practice 50 years ago. all the 3 layer cedars i have torn off i havent seen any underlayments.

Always tear off and resheet the cedar. In all the years I have roofed, never heard of wht you are asking.
Plus - more labor but big bucks for you !~~

First off the manufacturer will void all warranties of this. I would run and tell them if they want it done this way they can do it. Remember you are looking for customers like they are looking contractors. Same thing. You dont need to do everything that walks in the door.

In the old days when i was a tear - off labor a project like this was done on a very old hotel in my area by one of the biggest oldest companies here .

The roof had no access and it was a very very steep cone with like 10 sides around of about 5-6 squares each .

They removed both layers of comp and left the bottom cedar shingles .

They layed a backwards layer of cap sheet to smooth the surface and they shingle 25 year 3-tabs over it just to keep the same old antique look .

The cedar shingles where still in decent shape believe it or not . Roof is still standing and this is right next to the ocean.

They probably did a very good buck in it .

Both the companyand the roof are still in good shape until today.

at least 10 years have gone by


These situations come up. We may have done the same thing. You have to evaluate the job. Customers budget is a part of the evaluation. Residential this is not done as much.

That is why all the rigid answers given here most of the time. **Do it this way or you are a jerk. **

I have done a lot of things to keep a roof together. I would be called some kind of rookie for doing.

The funny thing is I am an expert in my trade. I will work inside someones budget to protect their investment. I will not say this is it or let your property fall down.

That depends on what kind of contractor you are. I would not risk ruining my good name in the community by roofing over old rotten cedar. You cant let your customer right your specs.

i think cedar is very different based on location. the ceadr i tear off is generally 160 years old and very brittle (and light in weight) the cedar you are taking off may only be 50 years old and 3 times as thick


Nobody said anything about roofing over rotton cedar. Or letting the the property owner write the specs. Let me know where you seen that written?

I built a very good reputation in my community doing what I just stated. :slight_smile:

ditto everone for chriminey sake.


In my few months in Dallas

Ive figured there must be atleast 40-50% of the homes with comp over shingles (thats alot of houses), anything built prior to 1994? and to me this just shows the quality of the installers in this area. HORRIBLE

Dont get me wrong, there are a few good roofers here but…

I could go off on a 3 day tangent trying to tell you guys what going on around here but…

Ill post my own thread with a photo…