Thanks in advance. Short story is we have a small leak coming in around our bathroom vent pipe on our flat, modified bitumen roof. Just got back from the supply house where I learned that they only have the lead boots in one height, about 1.5' or so. I know that the vent up there now is at least three feet or so.

So, question is, can I just cut down the existing vent? Will it do any harm? I suppose I can just go at it with my reciprocating saw. But I want to make sure I am not violating any codes or rules. This was a roofing supply house, so I was surprised they only had them in one size. Is that common?

Thanks!

Stubits

When you do it on a regular basis it's not so tough, I know, however opening up one's roof, especially a flat roof is an intimidating project.

Tom, Kiss, thanks so much for your patience and understanding. Milo, I apologize if this has some how offended you.

KeepItSimpleStupid

Before long, your going to have enough expierience to open up you own handyman business

speedball1

Stubby,
Let me tell you how I open up a roof for a vent stack. You have a pipe leading up to the roof. I take a plumb bob and plumb down to the center of the pipe from the roof. I mark the roof and take a protractor and scribe a hole a little larger then the pipe. Then simply drill a hole and take a Saws-All and cut the hole. You may now extend the vent and install the roof boot. Sound easy?? Good luck, Tom

Milo Dolezal

I was only joking. No offense. Glad you are all set to install the correct flashing ! Milo

Stubits

Tom, actually it sounds easy enough. I have just read too many horror stories about the difficulties of flat roofs and really don't want water damage.

Milo- Sorry I misinterpreted your comment. I am just working hard to bring this old house up to where it needs to be. We love it and it is in wonderful shape, but there's always something!

speedball1

Hey Stubby,
If you're concerned about a roof leak, after you install the roof boot and everything's done take a hose up there and load the area up with water. You may now go back and check for leaks.
It's my bet you won't find any. Good luck, Tom

Milo Dolezal

Stubits....you got many good advices ... I would like to add my 2 cents:

I assume you have roll-on roof. You can also to this: scrape clean area where flashing will sit. Spread Henry 208 roofing cement around the vent and where the flashing will sit. Install the flushing. Push it into the roof sealant. A bit of roof cement should squeeze out from around the edges as you pushing flashing down. Screw flashing to the roof . Make sure it sits flat and that edges are not buckled. Take more Henry 208, spread it around the perimeter of the flashing edges with 4" putty knife. Use roofer's mesh over the edges. Push it into the sealant. Go over it with another coat of Henry 208. The mesh should be completely covered. Be generous.

Don't buy the sealant in caulk-like tubes. It is cheaper to buy a one gallon can. You will probably use it all.

I understand the problem associated with using nails/screws on the roof - but unfortunately, if you don't properly attach your flashing to the roof framing, the edges will pop up with heat.

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Stubits

Milo, thanks. This is perfect!

speedball1

Good morning Stubby,
Let us know how you make out. Good luck, tom

Stubits

Today is the big day.

So, I was planning on using Henry 505 Flashmaster. The directions indicate that the surface must be clean and dry.

It rained last night and the roof got wet. How long should I wait before I start this project? How can I tell if the roof is dry enough? Is there anything I can do to help the drying process?

There is a chance of rain this evening. How long does the roofing cement need before it can get wet?

Should I wait for dryer weather to do this? Or, should I use a roofing cement intended for wet applications like Henry's 208R? Are they as good? I already have the 505 stuff.