I have a 5′ x 10′ flat roof over the main entrance sheathed with 3/4″ Advantech. The roof has a 1/4″/foot pitch from the center to the sides. The flashing for the roof wall joint is 20 ounce lead coat copper and is 3″ on the roof and goes 8″ up the exterior front. This 10′ length will be done with three pieces. The roof edge drip flashing is 3″ on the roof, 1″ down and then a 3/4″ kickout.
How should I join the drip flashing at the outside corners ?
How do I integrate the drip flashing and the wall flashing where they meet at the house ?
Edit – Attached is a picture of the roof prior to “disassembly”
Much Thanks in Advance,
Eric S.
Edited 9/24/2004 9:34 pm ET by Eric Svendson
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Generally, caulkl, fleable, but that type depends on the kind of roofing material. You diodn't mention that item.
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Roofing material will be latex rubber paint and fabric from Resource Conservation Technology .
Eric S.
as a generel rule, how do they recommend tying it to a flashing?
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I'm not so much "worried" about tieing their roofing system into my flashing - they provide excellent instructions for that, i.e. apply about 6" width of a wet coat of their paint to within 1" of roof edge and embed their 6" reinforcing fabric into that wet coat. So, forgetting about the roof/wall flashing for the moment, I would have drip flashing running around both sides and the front. Then a 6" width of their paint, and a 6" width of fabric and then saturate the fabric with a coat of paint. Then start doing the meat of the job.
My problem (and possibly I'm being a little over-cautious here) is how to mate the drip edge with itself at the front corners, i.e. a simple lap or a rabbit type joint ? And, likewise, how to mate the drip edge with the roof/wall flashing.
Is there a "best way" to do this?
Thanks,
Eric S.
Here is picture I tried to attach with an edit.
How should I join the drip flashing at the outside corners ?
My prefered method is to turn the corner with the drip edge by cutting thru the horizontal surfaces and then bending the verticle flange 90 degrees. In my case, I'm usually locking a copper pan to the drip edge, so the missing square at the corner doesn't show. It will in your case. The other method is to cut one side slightly longer and fold the vert. flange so it under laps the piece on the other side of the corner. When you join two pieces of drip edge in the middle of a run, snip about 3/4" of the fold on the front off at a 45 degree angle. This will let the next piece slide over and the vert. flanges mate better.
How do I integrate the drip flashing and the wall flashing where they meet at the house ?
Install the drip 1st, and make a 1/2" hem at the bottom of the flashing. Lock the hem to the drip. Squeeze it tight. I'm assumming the drip is also LCC.
How are you going to connect the railing to a paint on roof?
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Edited 9/25/2004 6:18 am ET by greencu
Hello Greencu - As you see, I took your previous advice on the Advantech - $35/sheet. It is not fun to join that T&G when you have a 1/4" pitch. Couldn't get any local response re the flat seam copper but the Resource Conservation folks are here in Maryland so I figure I give it a try.
I applied a prime coat of their paint to the sheathing yesterday and it truly feels like rubber when it dries.
Thanks for the tip on joining "middle of run".
When you say "make a 1/2" hem" - doesn't that require me to solder a 1/2" x 3" piece to the flashing?
I plan on using powder coated aluminum railing to sorta duplicate what I had in iron. It was also not fun getting that iron railing off the roof even with scaffolding. The aluminum railing will be screwed through the deck with SS lags. I repaired some rotted 2x8 and put it blocking where I hope the railing will go. But my main thrust now is to get on with the fiber-cement siding and the flashing problem was holding that up.
Thanks,
Eric S.
When you say "make a 1/2" hem" - doesn't that require me to solder a 1/2" x 3" piece to the flashing?
Nope- just fold it under so it locks. Shouldn't be any problem between the LCC and the alum.
The aluminum railing will be screwed through the deck with SS lags. I repaired some rotted 2x8 and put it blocking where I hope the railing will go.
I'd think twice or maybe 3 times before making a hole in my new roof membrane. Can you raise the rail an inch or two or will that cause problems with the wall connection point?
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I would use a caulk compatable with the material for the roof to seam between overlapping sticks of metal at the joints you mention.
A couple more points here based on you other info.
Normally, the main surface membrane will be placed first, then the metal trim, then the strips over it. That way, should there be a failure of that joint ( this can be more common than you think, partly because of the thermal expansion in metal) the few drops that get behind the metal meat up with a layer of roof membrane instead of wicking into the roof sheathing and starting a new case of rot.
Then, when applying the metal. I like to have it nailed down near edges at least every 4 to 6 inches. I see some guys stretch this out to a foot or three. That is fine for a shingle job, but with a waterproof joint like this, if the metal puckers uop from thermal movement, it will break the seal and leak very son.
After the metal is nailed over the primary membrane, it is time to strip off the edtges like you describe, except that, unless this stuff is realy suberb quality, that I would do a first strip 4" wide. and then a second one 6-8" wide such that the second overlays the edges of the first. This double seal will make sure it keeeps performing the life of the rest of the product.
Then ------afterr doing all this work, you want to poke holes in your roof by screwing a railing down to it?????.
be sure when setting it to lay it all out, then mark the screw holes and predrill, then put a bad of caulk in and around the hole, then screw your mounting plate down. That way, it is set in the caulk and there is something to prevent moisture from following the screw path into the sheathing. i see that done too oftern and what happens is that this moisture weakens the wood fibres very soon so the railing wiggles and draws even more water inside. From there, it is all downhill.
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Thanks Greencu and Piffin.
Eric S.