You are here:

Roofing/When to do and which shingle?


"Its time for a roof. I am the center unit of a 1984 three unit, two story town house. My house foot print is between 900 to 1000 square feet. Roof pitch I was told is 8 over 12 (looks like 45 degree angle to me maybe steeper). Very simple inverted V design, no complications, ridge vent, chimney with cricket, two pipe vent penetrations,.... My roof is 15 years old there are two possible three leaks (not bad and not every time it rains) and there is 30 year old fire treated plywood that is swelling and holding moisture.

FIRST QUESTION: I live in South Eastern Virginia, Hampton Roads area. The winters are generally warm and mild but we get a cold snap below freezing for short times. The roofing companies say they could do this job in one day. Should I have the roof installed in this January - February winter or wait till March if the leaks are not bad? Should I agree on a weather forecast with the roofer? Will the shingles melt together and seal properly?

SECOND QUESTION: I have had two qualified roof estimates that include architectural shingles, gutter replacement and fire retardant panel replacement. One for GAF Timberline (roofer included a 10 labor warranty) @ $4,200, and one for Owens Corning Duration Shingles (roofer included a 5 year labor warranty) at $5,400. Both shingles give the same lifetime warranty, but is the Owens Corning worth $1,200 more? Thank you,Brian"

ANSWER: 45 degree pitch would be 12/12. You have 8/12 so it is 34 degrees
Best time to do a shingle roof is spring or fall. If you do them in the winter the shingles will not seal until spring and if you get a windstorm before they seal they could blow off. Also, in the winter the shingles are fragile and can easily break during installation. The summer is too hot to do them.

The Ownins Corning shingles are not more expensive. The roofer is more expensive. All shingles are about the same price. The price of shingles is a small price of the job. The labor is what's big. So changing shingles cannot change price that much.

You're lifetime warranties probably won't apply. They have so many excuses to get out of the warranty that it's just a gimmick. For instance, I remember seeing on a warranty where the manufacturer said it must be a single home. Since yours is not a single home that guarantee wouldn't apply to you. It shouldn't make a difference or not whether your building is attached to other buildings. They're just using it as a way out of the guarantee.


---------- FOLLOW-UP ----------

QUESTION: Thanks Brad, I appreciate the advice.  

Two more questions please.  The GAF literature says the shingles can be applied at 40 F or above.  They say you can opt to have immediate sealing if you apply quarter sized dabs of sealant on the back of the shingle (a lot more labor I assume).

Ques 1:  How long does it take for the shingles to seal?  If the ambient temperature is above 50 F for one day, will they seal or does it take several weeks of warm temps to assure sealing?

Ques 2:  If I can't wait till March, should I request the extra adhession for immediate sealing or is this inviting a sloppy job?


Yes, that would be a lot more labor. Also, as you apply it you bound to get some squueze out or drop ontop the finished part of the shingle. The steeper the slope the more visible that will be. Also, the dab of sealant only grabs one center spot of the shingle tab where the glue strip grips the entire shingle tab. The glue strip will be superior. Also, GAF says that if you use too much cement it will blister the shingle. How do you know the exact amount.

They probably won't seal until you get in the 60s with sun or 80s without sun. They will seal in one day with the right conditions. The sun beating down on the roof will make a big difference. In the summer the side with the direct sun can be so hot you can't sit on the roof and have to quit or move to the other side. You can't get direct overhead sun until late spring.

If you can't wait until March just get it done and hope you don't get a high wind storm. The roofer also has to know how to handle shingles in cold temperatures. Many roofers just slap the shingles around braking them.



All Answers

Answers by Expert:

Ask Experts


Brad Zacharia


All aspects of residential Roofing. This includes shingles and flat (low slope) roofs. I have knowledge in the installation as well as the design of roofs from an engineering standpoint.


I have been doing roofing for 40 years. This was my father's business and I took it over in 1980.

I have written responses to artcles that I felt needed a response to and those responses have been published in roofing trade magazines.

BSEE Drexel University

©2017 All rights reserved.