Chimney flashing to low slope roof


#1

Looking for chimney flashing advice. I am a homeowner in NH and I just finished putting on a modified bitumen rolled roof on the low slope roof of the dormer on the back of my house. It is all done except for the flashing to the chimney. The brick chimney is centered on the peak so I don’t need a cricket or anything - front half on steep shingled roof - next year’s project. What I took off when stripping was lead flashing completely covered with asphalt sealer and the silver coat to protect the asphalt. Is this the best system to replace it with? Looks similar on other houses in area. All internet ref show base and cap formed galv or copper flashing for shingle system. Should I nail the lead to the roof? The base sheet is supposed to be self sealing. Or should I just stick it down with the asphalt sealer? I left about 4" of the base and top sheets up the chimney - except at corners. What is the best way to open the mortar joint that is still in very good condition? Cold chisel or masonry blade on saw? It is a 4’ sq. chimney. Thanks


#2

Would love to see a photo so I could better understand what you have, and to give you good advice. I will say this, do NOT use a cold-chisel on your mortar joints. You will want to cut the mortar joints to create a reglet. You can do this with an abrasive blade in a cut saw or grinder. The grinder would likely serve you better, as it would be easier to work with.


#3

a separate, but similar sheet is torched to the bricks (which has been primed with asphalt primer)the height is to be no less than 8" above the cant strip.you did install a 4"cant strip around the bottom of the chiminey? then termante the top with a manufacturer approved system.now you know


#4

Here are pictures of the chimney that I need to do the flashing on. Sorry it took a while to get them posted. Thanks for your advice.
picasaweb.google.com/nhredpines/ … ngPictures


#5

soprema or siplast??


#6

Id get a good lead guy if I were you. But if you want to do it yourself you can use Hydro-stop premium coat system and they sell a clear waterproofing sealer for your chimney too. www.hydro-stop.com they can match the color of the bricks or the roof material so it will look pretty for you.


#7

dear homeowner ,
you option would always be to put back a lead or a copper flashing as this would out last any thing else , and would be money well spent , try and find a good contractor to carry out this work .

personally i would use lead as it can be bossed and welded to form a water tight seal around any chimney .

regards a english roofer


#8

You should flash the chimney separately with the same membrane as per manufacturer specs and could terminate with a pressure plate at the brick. As Roofboss said at least 8" high off the roof. We always run our mod bit wall paper style on sloped roofs.


#9

Dont trust acrylics for waterproofing…

I would flash it with modified and cover it with metal for looks.