What is the best way to fix a flat roof? - Posted by Mike

Posted by GL on January 30, 2000 at 09:29:22:

You should have 1" of loose gravel on top of the tar to protect it from the sun. Over time it washes away and disappears into your lawn.

If you do it in real cold weather (like now)the top layer of tar can be scraped off along with the embedded gravel.

Then you recoat with tar, and put on fresh gravel.

Obviously this is easier and cheaper than replacing the whole thing, yet it results in a roof that will last as long as a new one, and for all practical purposes is new.

But you can only do it if your roof is still in good shape. If you let it go for too long the whole thing needs to be replaced.

Since I can’t see your roof from here you will have to get some local roofers to look at it and give you a price.

My new roof cost under $3 per square foot for a 5 ply tar and gravel job.No new boards or rafters were necessary. You should be able to do better if you get competitive bids.

If it only needs some repair and recoating it should be less than half.

Make sure you get someone who has a tar pot and is experienced on that type roof. Don’t let them sell you the rubberised membrane unless you have almost enough slope to use shingles, and the roof drains so well you never have water laying on it.

What is the best way to fix a flat roof? - Posted by Mike

Posted by Mike on January 29, 2000 at 20:12:04:

I have a 2-unit property with a flat roof that has a couple of leaks. I was in Home Depot and noticed that there are products that are designed for flat roof structures and are a tar type substance that you simply apply with a sweeping action. Is this recommended or are there different products and procedures that should be used?

Any thoughts would be appreciated.


Re: What is the best way to fix a flat roof? - Posted by Bob Hanson

Posted by Bob Hanson on January 31, 2000 at 01:25:32:

I have had VERY good luck with the rubberized AKA “dividend” rolled roofing. Applicator needs to make sure they apply it right - continuous seal along the edges. Most of the roofs I used it on had a very slight pitch but 1 was dead flat (even a slight sag in the center and it held up fine. Good luck

Bob in (snowy) Hyde Park, NY

Re: What is the best way to fix a flat roof? - Posted by Laure

Posted by Laure on January 30, 2000 at 10:47:49:

I’ve been using the rubberized roofing system that Menards sells. I have had great luck with it, and on a resale, I can really push the Rubber Roof as an advantage instead of a flat roof being a huge negative.

Laure :slight_smile:

How to make a roof last forever. - Posted by GL

Posted by GL on January 30, 2000 at 08:24:09:

I had a new tar and gravel roof installed a few years ago. They normally last 20 - 25 years. The roofer told me the secret of making it last forever.

When the roof is 10 years old, have the roofer come back and recoat it. They sweep away the gravel, scrape off the top layer of tar, and recoat with new hot tar. Then they put the gravel back, adding more if necessary.

Have this done in cold weather, the colder the better. If the tar is really frozen it cracks away easily and the new tar goes on thicker.

You see the top layer eventually dries out and cracks, allowing leaks. If you do not fix it properly the leaks rot out your boards and rafters, and you have to replace the whole roof.

If you recoat periodically you have essentially a new roof all the time, for a much lower price than a complete new 5 ply tar and gravel job.

Depending how old your roof is and how far gone, they should be able to fix the leaks and recoat.

Re: What is the best way to fix a flat roof? - Posted by BRnBA

Posted by BRnBA on January 30, 2000 at 04:16:52:

Mike, you can buy mobile home roof coating and put it on with a paint roller(3/4" nap). I like the white roof coating better than the tar stuff, it lasts longer. I have applied it to rolled roofing and even over the rock type roofs in a small area however I would recommend getting a few bids and recommendations from local roofing contractors before making a decision on how to procede.

Re: What is the best way to fix a flat roof? - Posted by Corey

Posted by Corey on January 29, 2000 at 23:18:12:

Is there rock over the tar or just rolled roofing? If there is rock then you have problems, rolled roofing your in luck just buy the proper roof coating and apply it to the seams or leaking areas. IF there is rock then build a peak roof over the old flat one and shingle it!!!

Rubber Roofing - Posted by Susan (N.Ca.)

Posted by Susan (N.Ca.) on January 30, 2000 at 12:28:15:

I’ve never heard of this, can you elaborate a little please.

sweep away the gravel? - Posted by JD

Posted by JD on January 30, 2000 at 08:47:47:

The tar and gravel roofs I have seen have the gravel embedded in the tar. Very difficult to remove. Did the roofer tell you how much a recoat would cost?

Re: Rubber Roofing - Posted by GL

Posted by GL on January 30, 2000 at 13:00:30:

It is a rubberized asphalt substance. It comes in big rolls like roll roofing. The installer unrolls it on your roof, overlaps each strip on the one before, them seals the seams with a special propane burning heat seal unit.

It costs half or less what a proper flat roof costs but I don’t like it at all. Two people I know got it on their roofs and it was no good, had to be replaced.

It may be OK if it is used properly. I got the literature from Firestone, and they do not recommend it for a perfectly flat roof. it needs a little slope. If the water can lay on it after a rain, don’t use it. You have to read the “fine print” carefully to discover this, they don’t exactly stress it.

The installer has to know what he is doing, and they must have the correct tools. It is quite different from any other roof method. If it is not done right it’s a mess. I wouldn’t use it myself unless it was a peculiar roof, too steep for tar and gravel and too shallow for shingles.