Installing Vent in Tar and Gravel Roof

I want to have an 8" metal vent installed for a bathroom master fan. I have a tar and gravel roof, and I am wondering what the correct procedure is for installing the vent. I talked to multiple companies who wanted on the order of 1200.00 to do this. Those quotes seem unreasonably high. The roof is a 2/12 pitch tar and gravel roof in the detroit area. Anyone have any thoughts on how to install the roof flashing and vent pipe?

Reply to
warrenshudson
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I understand I have to cut the hole, but do I want to chip away the gravel out of the tar first, before cutting through? Also, does the flange on the pipe jack need to go under the tar and tar paper, or does it merely go on top, and get liberally taped/tared/taped/tar.... ?

Also, what can I expect to find under the top layer of gravel and tar? I assume more tar and tar paper, but will the flange "slide" under the tar paper to the plywood, or do I need to cut back the tar to the

*outside* of the flange on the pipe jack ? the roof base I am going to use can be seen at
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I am going to use the adjustable 8" one
Reply to
warrenshudson

Ok. So it is really not like a shingled roof at all, because in this case, even the part of the flange closest to the peak of the roof is on top of the actual roof surface, where on a shingled roof, that part of the flange is below the shingle corse towards the peak of the roof. What is the best method of getting all the gravel out of the area the flange will sit? most of the gravel is stuck into the exisitng tar. Also, when I get the gravel out, how do I go about leveling the roof surface so there will be no voids for water seepage under the flange? Just use tar? Thanks a lot/

tom wrote:

Reply to
warrenshudson

I'd do it by hand, with a flatbar and hammer. It doesn't have to be perfect. Just get the highest rocks out, then maybe the lesser ones somewhat. Just use tar. Tom snipped-for-privacy@gmail.com wrote: >snip- What is the best method of getting all the gravel out of the area the

Reply to
tom

Ok. Thanks a lot tom, I appreciate the help. Do you have any recomendations for a type of tar I should be looking for? I am probabaly going to need something that is fairly thick so that i can build up a bed of it for the flange to sit on top of. At the same time, I need something that wont leave any voids between it and the uneven roof surface. Thanks again

tom wrote:

Reply to
warrenshudson

The thickest type you can manage to spread. Tom snipped-for-privacy@gmail.com wrote: Do you have any

Reply to
tom

What I used to do when needing to deal with tar; buy a bucket at a home improvement store, set up a grill, hibachi or whatever, heat it while getting the site ready then haul it up with a rope when needed, wear gloves & appropriate safety gear. The hot tar spreads so nicely.

Reply to
Eric in North TX

That is probabaly exactly what i will do. I like the hibatchi idea, though, so I can make my lunch too. Maybee i will just forget the bathroom vent :) actually, would that be "trowel grade" roofing cement?

Eric > What I used to do when needing to deal with tar; buy a bucket at a home

Reply to
warrenshudson

"would that be "trowel grade" roofing cement?" I'd think that would be appropriate.

Reply to
Eric in North TX

adding this will create a future maintence headache as things expand and contract differently over the years. better to vent out a wall......

Reply to
hallerb

Any penetration of a tar and gravel roof at the roof level will eventually leak because of movement, even if just expansion and contraction. It is best to build a curb around the penetration. The curb can be securely fastened to the roof so it moves with the roof. Then the inner part of the curb can be filled with a flexible sealant up several inches above the roof. A metal flashing can then be secured tightly to the penetrating pipe, extending like a tent out over the edge of the curb to keep rainwater and sunlight off of the sealant. Any roofer who does commercial flat roofs can give you details.

Don Young

Reply to
Don Young

Reply to
warrenshudson

Some sort of metal weathershield secured to the pipe to keep rain (and especially sun) off of the sealed area would help. You might want it easily removeable for inspection. Don Young

Reply to
Don Young

Reply to
warrenshudson

What I had envisioned was sort of like an umbrella, tightly clamped to the vent pipe slightly above the roof level. Some vents actually come with something like this. Keeping the penetration area protected from the weather will improve the life of the sealing quite a bit.

D>> > Don- I am sure that is probabaly true, however, the kitchen vent is

Reply to
Don Young

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