The item you call a GI, is actually called a Gravel Stop Metal Flashing.
Also, "TAR" may or may not be technically correct. There is a difference in chemical composition between, "Asphalt" and "Coal Tar Pitch" roofing, which both are heated "TAR" products.
If in fact, the roof is really composed of "Coal Tar Pitch" rather than "Asphalt", then you need to purchase a Coal Tar Pitch Roofing Cement, rather than the common regular roofing cement and that would probably only be available from a roofing supply house.
The sheet metal, usually Galvanized Sheet Steel, has a different coefficient of expansion and contraction than the built up roofing materials, so where the roofing plies should have been bonded to the sheet metal, the seal was torn apart from the movement of the sheet metal.
If the substrate and metal edging is cleaned of and all embedded gravel is "Carefully" Spudded and scraped away from the metal edging, then a repair can be done quite simply, using just common plastic roofing cement and reinforcement fabric, either asphalt saturated cotton, polyester or fiberglass materials for the fabric.
Here is an excerpt from a thread from around 2 years ago, relating a similar patching question.
http://www.diychatroom.com/f9/roll-roofing-repair-9191/
To temporarily, (like for 2-5 years of waterproofing time) patch just that area only, without doing the whole roof, you should apply a layer of plastic fibered roofing cement in a light but consistently thick application over the seams for just a littly bit wider that 6 ". Buy a product called patching repair mambrane. Other names are
minnie, ( asphalt impregnated rolls of cotton fabric), or it can be composed of fiberglass too.
Take your trowel and "Gently" embed the fabric into the previously applied roof cement, which will split the difference of each of the seams, 1/2 on each side of each of the seam.
Oh, and the bottom one, (the seam closest to the gutter or eave edge), will be the first one then the two side ones then the top seam.
After the bottom fabric is gently troweled into the roofing cement, apply a "Thin" coating of roof cement over the surface of the fabric. Just heavy enough so you do not see the fabric or pattern of the fabrics weave. If you apply too much cement on the surface, the sun will crack it and when it cracks, it will create further cracking to anything that it is adhered to.
After all 4 side seams are covered in this manner, lightly trowel in more plastic roof cement into the center of the square so it does not hold and retain water. Make this center area level with the side seam edges.
If you have extra fabric membrane after you do the 4 sided=s, then use this in that center area also to prevent future cracking as stated before.
Go from left to right when applying the fabric and roof cement in the center of your patch area.
At the top horizontal seam, make sure the edge of the roof cement is nice and smooth and troweled down to a nice taper, so water will not work its way into any large gaps or remain ponding there.
"Think Like Water" is an expression I like when doing repairs. Where would you go if you were being diverted from your natural gravitational path?
Once a year, check on the condition of the surface exposed roof cement and see if it is getting burned out and starting to crack. If it is significant, then just apply a light coating of roofing cement to the surface again, but the initial patch should weather just fine for the first 2-3 years before needing this maintenance procedure.
Final note: To save the bucket of roofing cement that you purchase, (5 gallons = about $ 15.00), after you are done using it, trowel the top surface nice and smooth and pour a couple of inches of water on top of it. Save the lid and tap it back onto the 5 gallon bucket and crimp down the lids fastening flanges either with a hammer, a screw driver, or the pointy tip of the trowel and store it away. The next time you need to use it, the top will look a little grey instead of black, but it will still be soft and trowelable after you dump out the water, (if the bucket doesn't rust out).
Clean the trowel blade by scraping the excess roof cement into the side edge of the bucket and let it sit in a coffe can filled with gasoline for a day, then wipe it clean with a disposable rag or jab it into some loose dirt or sand and it will be like brand new again, except for how messsy you will have gotten the handle and your fingers and your hand. I guarantee you will find roof cement on parts of your body you didn't even think you touched.:laughing:
Ed
P.S. There was recently another thread about doing a "
dope", (roof cement), and
minnie patch which had a lot more replies, so if you need further information, just click on the previous threads or do a search for the word "
Jute " or "
dope and M
innie", because we got into a tangent side discussion about the various terms around the country used for similar products.
Here is just a minor add on for some terms that may be geographically different, but describing the same things.
http://www.diychatroom.com/f9/flat-roof-question-20182/
Some guys call it Bull, since it is a Bull Chit way to permanently patch a flat roof, but it can be done to last a long time if done correctly.
It is also called
Dope, Black-Jack, Plastic Roofing Cement and Buckets of Roofing Tar, but it is all the same.
In my region, we call the plastic roofing cement,
Dope, and the mesh fabric,
Minnie. To each their own.
Here are some instructions on how to do a
Dope and
Minnie patch.
http://www.diychatroom.com/showthrea...nnie#post49430
For further installation instructions, do a search under my user name and search posts, not threads, for the term;
Dope and
Minnie.
