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Flat Roof Leaks

2203 Views 4 Replies 5 Participants Last post by  hottinroof
I have a approx. 15 x 20 flat tar-gravel roof that started to leak a few months ago. I spent $400 for all the seams and cracks to be repaired (attempted) but now leaks have sprung up elsewhere. I have been qouted $1500 for rubber replacement with 30 yr. warranty. The problem is I am currently selling the house and am not able to spend any more than i have to. I just want a reliable fix to satisfy the current tenants.

I have the ability to repair myself but am wondering what brush on/spray on sealants are best. I have seen many products that claim rubber-like results on the internet but don't want to pay $160/5 gallon without opinions.
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Some roofs cannot be repaired if they are too far gone.Sounds like this is the case with yours.Don't waste your money on repairs.A new roof is a good selling feature.Just my 2-cents.
I have tried different types of materials to fix these types of leaks including : Blackjack (No longer made) and a newer product called Roof Kote but I to have failed to stop the leaks that I have been working on. I feel that most of the problems that occur with flat roof leaks are the toll that the weather and time take on the surface the best way than i have currently came up with id to slightly pitch the roof and apply shingles or rolled roofing.
The only way to repair a flat roof, is to have years and years of experience diagnosing the possible points of entry and determining if it is even repairable in the first place.

Roofing Cement, by itself would only provide a 3 month to 2 year life cycle for sustainability, due to the cracking that will occur to the product when applied, it has a solvent in it to make it capable of being troweled in place.

For mastics such as this to last longer, a 3-ply method must be utilized, with the first coursing being the mastic, then either a cotton, fiberglass or polyester fabric being set into the mastic and then a surface skim coating of additional mastic.

The area being repaired must be free of dirt debris and and aggregate gravel surfacing, which must be spudded away carefully, so as to not create any further leak problems next to the repaired area.

If the roof has already been repaired with fresh mastic, (aka, roofing cement or plastic roofing cement), then any new roof surface coating will not adhere to that for any period of time, due to the solvents contained within starting to leech out of the product.

You would definitely be wasting your money on that type of repair venture.

Also, the type of tar that was used needs to be confirmed. If it is asphalt or bitumen, then re-roofing over the top is a viable option with the EPDM Rubber Roof. If, on the other hand, the product is Coal Tar Pitch, then the covering directly over the existing roof, without additional separator sheets will allow the chemicals to contaminate the newly installed roof membrane materials and they will decompose prematurely.

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You should be able to get the costs back by installing a new roof, plus, as JohnK mentioned, a new roof is a great selling point. When we sold our townhome we definitely made sure that our new roof was mentioned as a selling point. BTW, BlackJack is still made/available from these guys: Gardner-Gibson. I'm not sure which product you used but if a new roof is definitely not an option you could try one of their roof cements.
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