Roofing New roof over existing roof a good idea, cannon answer, asphalt shingles

Roofing New roof over existing roof a good idea, cannon answer, asphalt shingles


Expert: Stan Skarbek — 4/22/2004


Wow Stan, thanks so much for your speedy reply!

Based on your experience, what do you think a typical difference in cost might be for roof-on-old roof versus tear off? The house we’re looking at is about 1700 sf.

Best Regards — Mason

Followup To

Question -

Hello Stan

My wife and I are in the process of purchasing a house that needs new roofing material. It’s a 2 story cape w/2 dormers. The existing asphalt shingles are the only layer of roofing on the house.

I’ve heard divided opinions about whether it’s better to remove the old shingles before putting the new ones on, or just install the new shingles right on top of the old ones.

Which do you think is better — and why?

THANKS! Mason & Anne Marie Cannon

Answer -

Hi Mason & Anne Marie,

In terms of function, there’s hardly any benefit in tearing off the existing roof. It’s true that toward the end of the life of the roof, you may gain a year or two if you have the previous roof torn off, but that’s a minimal benefit.

The main benefit is how it will look. Since the base you’ll be putting the new roof over isn’t smooth, it will result in the new roof being even less smooth. It won’t be a huge difference, but if you have two roofs next to each other, you’ll definitely be able to tell which one went over the the old roof and which one had the old roof removed.

The other issue on appearance is around the edges. On most edges, in most roof situations, the roofing contractor will cut back the edge of the old shingles and install a 1 1/2" metal nosing on the edges, to hide the old roof. Some folks don’t like the appearance of the nosing.

The money is the main issue. Do you care enough about the minimal appearance difference to spend that much money? Ask each contractor for the address for a roof which has been installed over the previous roof, and one where they did a tear off. If you can’t see much difference, on that issues, then put that money you would have spent on a tear off, into your vacation fund. Feel free to follow up with further questions. Good luck.

Your roofer with a keyboard,


Hi Mason,

The prices range dramatically, depending on many factors. If you happened to live in San Jose, CA I could give you an idea of the prices. But every locale has unique issues that jack the price up or make it very low. For instance, the cost for labor in San Jose is very high compared to Fresno, CA which is only a couple hours away. Recycling of the old material can be extremely expensive in some areas (like San Jose) or very inexpensive, like in Orange County where my son is a roofing contractor.

Each house also has unique features like steepness, access, nails or staples in the old roof, multi-level, driving distances, unique flashings/vents, chimney issues, yadda, yadda, yadda.

But I can still help you on this. I can give you some very good advice, which is, get at least 3 bids. Don’t be hesitant about it. All roofing contractors know that they are bidding against other contractors and they won’t feel like you’re wasting their time, just because you solicited many bids. It wouldn’t be a bad idea to get 5 bids. Roofing prices can vary widely. If you get 5 bids, you’ll start to get a sense of what the local market is for roofing. That’s the very best way to get a good idea on the prices that are reasonable.

I hope that helps. Since I don’t do pricing issues on my first inclination was to click the automatic response button that says "This question isn’t in the catogory of questions I answer", but I also didn’t want to leave you without an explanation and without giving you the suggestion for 3 — 5 bids. For what it’s worth, anyone who gives you roofing price information, unless they can look at your specific house, is just taking a wild guess and hoping to sound authoritative. Especially online.

But any other detail questions on your roofing issues, please feel free to follow up with further questions. Have a great day.

Your roofer with a keyboard,

Leave a Reply