# repairing cracks on a flat roof



## j_midcentury (Jan 31, 2013)

I have a mid-century modern home with a completely flat roof. There are now some cracks in the roofing material, most are about 1/16" along the seams, but some are wider where the roofing material curves up to the metal edging (see attached pics). I'm considering doing a DIY repair job with Henry's 209 – ELASTOMASTIC® ROOF PATCH and the accompanying 183 Reinforcing Fabric. My goal is to just get through this So Cal winter, as I know that a new roof is overdue. 

My questions are:
1 - Are the Henry's patching products I mentioned a good solution?
2 - Are my cracks too big to be patched?

Thanks in advance for any advice.


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## jagans (Oct 21, 2012)

Do you have blisters in hot weather? Like air pockets (Bumps) on the roof?


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## j_midcentury (Jan 31, 2013)

Not really. Overall, the roof looks pretty good. There are some bumps where the roofing material was applied heavy, but no blisters.


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## 1985gt (Jan 8, 2011)

Nothing wrong with repairing it that way as long as you remember that it will not last forever.


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## HomeSealed (Jan 3, 2008)

+1. Repair away, it will buy you some time, but ultimately you'll need to replace it.


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## OldNBroken (Jun 11, 2008)

Don't waste your money on that Henry's crap if you can help it. I would suggest going to your bldg supply or preferably roofing supply and getting some modified mastic and cotton webbing. Karnak has always been a decent mastic.


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## jagans (Oct 21, 2012)

To repair things like the crack that you have shown, you are going to want to cut out the delaminated material. Remove all of the loose surface stuff that is scaling, as best you can. Brush the area to be patched with D-41 primer. Trowel on a thin coating of flashing cement. Embed 6 inch wide D-173 Asphalt Saturated Cotton Fabric in flashing cement centered on crack, and trowel in. Top coat with flashing cement. Trowel on second coat of cement, then embed 12 inch wide D-173 fabric. You need to use cotton, not fiberglass because it will conform nicely.


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## 1985gt (Jan 8, 2011)

I think a couple of people missed the part about only needed it to get through the winter in SO. cal....

FWIW Some of henry's products are actually pretty decent.


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## jagans (Oct 21, 2012)

I agree Sarge. The smartest thing that Henry did, and i gave them the idea, was to come out with a 2.5 gallon bucket of roof cement. Same diameter as a typical 5, half the depth, and weight. No black elbows. 

True story: I went to a distributor (SeaBoard) to pick up 30 cans of "Monroe" roof cement. I was apparently not supposed to go into one area of the warehouse, but I did. There sat cans with labels from abut 6 different sales entities and they were all being filled with the same mastic. The same thing happened when I worked in Bayway, the Exxon Refinery, (Whew, what a barren wasteland) all the tanker trucks from different fuel companies pulled up to the same watering hole.

I dont see whay he only wants to get through the winter if he has no leaks, or blisters, but he has a bad design there because he does not have a raised edge at his gravel stop. The bituminous to metal tie in always fails first on BUR's from dissimilar movement. That's why parapet walls and internal drains are better.


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## Chris Brink (Jul 5, 2012)

OldNBroken said:


> Don't waste your money on that Henry's crap if you can help it. I would suggest going to your bldg supply or preferably roofing supply and getting some modified mastic and cotton webbing. Karnak has always been a decent mastic.


Henry mastics have been extensively tested and proven to perform in a variety of conditions. Henry now offers warranties on certain of their products that the competitors do not offer.


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## OldNBroken (Jun 11, 2008)

Chris Brink said:


> Henry mastics have been extensively tested and proven to perform in a variety of conditions. Henry now offers warranties on certain of their products that the competitors do not offer.


Sounds like a Henry's rep. Things may have changed in the past few years with their products that I am not aware of.


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## hotrod351 (Jun 15, 2012)

looks like its already had some elastomeric put on it. id get some of the matting and go over the cracks with it, then put three coats on the whole roof. there now you have a new roof that should last for many many years.


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## DIYtestdummy (Jan 16, 2008)

Henry's stuff is TERRIBLE! I have the same scenario. The cheap local brand of "solarflex" is much thicker. After I patched the cracks it opened up and leaked again. It's better to just save some money replace the materials in the shoddy job.


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## jagans (Oct 21, 2012)

Test Dummy,

DId you embed asphalt saturated fabric into the cement and then top coat it? No roof cement will bridge cracks.


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## 1985gt (Jan 8, 2011)

Judging by it cracking again I would say not.


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## DIYtestdummy (Jan 16, 2008)

jagans said:


> Test Dummy,
> 
> DId you embed asphalt saturated fabric into the cement and then top coat it? No roof cement will bridge cracks.


 
Nope - I'm pondering this over a whole torchdown. It's only on the patio addition the previous owner paid non-licenced "contractors" to build. It was recommeded to me (by a HD Professional) that I just seal the cracks and re-coat it. I went the extra 2 miles and sealed all the potential leaks and coated the whole patio roof twice. I didn't have much faith in the products before I began, but they were also cheaper earlier in the week.


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## 1985gt (Jan 8, 2011)

When patching cracks with "mastic" you need to use a membrane to give it strength, I don't care what a HD professional says. Just ask anyone who has been in the roofing business longer then 5 years. This of course is not the best way to patch it but it will get you by for a little while.

Also the coatings do not do anything but coat the roof, expect not a lick bit of repairs from them. All they do is protect the roofing membrane, no matter what it is from the effects of the sun. If it is in a bucket and it runs like paint, it will not seal any cracks or stop any leaks for very long if at all.


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## DIYtestdummy (Jan 16, 2008)

1985gt said:


> When patching cracks with "mastic" you need to use a membrane to give it strength, I don't care what a HD professional says. Just ask anyone who has been in the roofing business longer then 5 years. This of course is not the best way to patch it but it will get you by for a little while.
> 
> Also the coatings do not do anything but coat the roof, expect not a lick bit of repairs from them. All they do is protect the roofing membrane, no matter what it is from the effects of the sun. If it is in a bucket and it runs like paint, it will not seal any cracks or stop any leaks for very long if at all.


Makes sense. I thought maybe I could get away with going cheap for a while. In rebuttal to good quality rubberized roof coating - the questionable parts of the rest of the roof are still sealed after about 5 years. That is only 1 coat, too. MUCH thicker than the Henry stuff and a little cheaper. I'll be saving for a new roof, though.

:yes:


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## jagans (Oct 21, 2012)

It was a rhetorical question. :wink:


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## jagans (Oct 21, 2012)

What did you not understand about me and 1985gt telling you to embed two plies of asphalt saturated cotton fabric in flashing cement? If you dry out the cracks properly, and prepare them as I said, the repair will last for quite a while. Like 5 years. Once the light oils leave, you can coat the patch with aluminum coating.

It amazes me when people ask you a question, then do something else.

Coating the cracks is not going cheap, its going stupid, like Homer,................. Homer.


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## DIYtestdummy (Jan 16, 2008)

jagans said:


> What did you not understand about me and 1985gt telling you to embed two plies of asphalt saturated cotton fabric in flashing cement? If you dry out the cracks properly, and prepare them as I said, the repair will last for quite a while. Like 5 years. Once the light oils leave, you can coat the patch with aluminum coating.
> 
> It amazes me when people ask you a question, then do something else.
> 
> Coating the cracks is not going cheap, its going stupid, like Homer,................. Homer.


[Butthead]Uh-huh-huh - he said cracks![Butthead]

Are you talking to *me*? Point was already taken, and I did not do something else after the fact. What did *you* not understand about what I said? 

And no, I still haven't gotten around to doing it proper yet - I have a balance issue and the right side of my body still doesn't cooperate; results from a brain injury. I had to jump off the roof last time. :thumbup:


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## roofingquotes (Mar 6, 2013)

You can always try repairing it yourself. If it doesn't work after all the repair then hire someone or let it check by a contractor.


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## OldNBroken (Jun 11, 2008)

Wow! This thread is all over the place.


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