Which type of roof should I go for?

[maddogchen]

Hello,

I have a house in sunny california. It has a flat tar and gravel roof with a slight slope for water to drain off. Its time for a replacement. I've talked with 4 companies. It seems like the slope is borderline for shingles. Two companies said they could do shingles. One company did not think so and recommended cap sheet with fiberglass and asphalt. The last company only does spray foam roofing.

So my options are to replace the tar and gravel roof with:

1. shingles roofing
2. cap sheet roofing with fiberglass and asphalt
3. spray polyurethane foam roofing

What would you recommend i go with for a flat roof with a slight slope. Should i take a chance on shingles, try this spray foam roofing or go with cap sheet? All the quotes were within a thousand dollars of each other.

Thanks

 

[Humpy]

How long did the original tar and gravel last? I would replace it with that. My current house has it and I wouldn't use anything else because a monkey could patch any leaks.

I live in the land of flat roofs and don't understand how a roof that originally had tar and gravel could possibly be suitable for shingles which are usually for a minimum 4/12 pitch.

Here, our flat roofs that are foamed also have gravel because birds like to tear up the foam.

 

[Greenman]

What is the actual roof pitch measured in inches per foot.
Is there insulation in the space between the roof and the conditioned space below it?
Is the appearance of the roof important?
Answer those questions and I can give you some advice.

 

[NutBucket]

Metal. Reflect that heat!

 

[NetWareHead]

Interesting thread. We have a flat roof property built in 1928 that has a tar and gravel roof. Same almost 100 year old roof. We found that tar and gravel roofs are obsolete and wont be replaced. One of the roofing contractor we spoke to mentioned what is typically done nowadays is to replace with a rolled rubber roof.

 

[Humpy]

Interesting thread. We have a flat roof property built in 1928 that has a tar and gravel roof. Same almost 100 year old roof. We found that tar and gravel roofs are obsolete and wont be replaced. One of the roofing contractor we spoke to mentioned what is typically done nowadays is to replace with a rolled rubber roof.

The method isn't obsolete as far as functionality.

They may be for business purposes though. I know of a few companies that stopped installing them because insurance for slinging around hot tar is significantly more expensive than for other methods and foam is far more profitable.

 

[Conroe]

Singleply is the way to go in under 3.5/12 pitch. Fibertite has great longevity. TPO for cheap. If the contractors are not offering it your talking to the wrong guys. EPDM (rubber) is good but the plastics have taken over flat roofing. With 1/2in fan fold insolation it can go right over just about anything. It's reflective and adds r value. It even comes in different colors. White is the most common in commercial, but we use tan and brown a lot on homes here.

 

[stormkroe]

I wired an administration building 2 years ago that had tar and gravel, a mall the year before that too. The hotels we wire always have rolled asphalt on the flat roof of the pool buildings. None of them are planar slopes, just drain to low spots with drain pipes.