Bracing a tall chimney to roof

[Alexander L]

Hi all!
I am going to be bracing a length of freestanding chimney and I had a question about making sure I properly seal (silicone, etc.) the angle brackets/hardware that will be screwed down to the roofing.

There will be a total of 13' 6" of pipe above the tee. This will result in 5' of pipe above the roof.
I will be using two extending roof brackets to brace, so that the chimney is supported about every 4 feet.

The first set of brackets will affix to the steep shingled side of the roof. The second set of brackets for the upper extending roof brace will need to be screwed down to the top of the roof... which is a pretty flat. The roof top is torch down bitumen. I am concerned about the proper sealant for this flat portion of the roof, as snow will occasionally sit up there on the flat part of the roof. I want to seal under and over these brackets in a way that will not result in any leaks. I'm at 6000' in the SoCal mountains... so not uber amounts of snow.

Is 100% silicone the sealant that should be used for the angle brackets that are affixed to a flat-ish surface roof top? Something better? I figure that the pro installers will be able to give me some tips on which sealant works best. Appreciate any info/advice!

Pics:

 

[begreen]

@Hogwildz has been a pro roofer. He will know if anyone will.

 

[Alexander L]

Thanks, bg.
Pic for clarity (bracket area), and a pic to show that I did provide 2" clearance from pipe at the roof edge... hard to see in my earlier pics.

 

[bholler]

We use either through the roof or geocell. Much better than silicone

 

[Hogwildz]

Hard to tell the height of the shingled roof area, but if it were me, I would mount the lowest bracket about 1" under the lowest shingle edge secured good the the fascia board , you can put a little urethane caulk under the mounting feet where they rest over the board and call that part done.

I always try to avoid putting holes in a roof unless really necessary, which I don't see in your case. I would mount the feet of the upper bracing directly under the drip edge (lower edge of the metal flashing)where the shingle roof meets the modified roof. Again, some urethane caulk under the bracket feet and done.
I don't really think you need any more bracing. If you decide to go into the modified roof, either use good urethane caulk, or google pitch pockets, which is what is typically used in commercial roofing with modified bitumen, and then they are filled with pourable sealer. It will seal great, but the stuff is messy to mix, messy to apply, and you don't want to get it on you, as it is a mofo to get off.

A good gust of wind on the last job I used it, and I took a mud bath, hair and all. Not fun.
Another thing to consider is if the roof leaks, and is under warranty, they may void the warranty unless the roofer who installed the roof, or certified/approved shop that handles that particular brand of modified does the work.

I say avoid the upper roof and keep is simple and clean.
If you install the brackets with a slightly downward away slope, it will keep any rain water, snow, ice from running towards the feet, by letting it run away from the roof direction and falling harmlessly to the ground.

 

[Hogwildz]

There was no need to cut the eave off, but it's done already. Make sure you get some sheet metal under the shingles all around the 3 cut sides to keep water away from the decking underneath.
You may want to consider a cricket on the shingle roof just behind the pipe to divert any downward water away to each side of the pipe.

 

[Alexander L]

Thank you, gentleman.

Hog, you saying I can get by with just one extended roof brace? ...or do you mean both extended brackets attached to shingles side, rather than dilly with the top of the roof (flat top)?
Ther will be 6 foot of pipe above that drip edge flashing where the shingles meet the flat roof top.

The cut out at the eave has a custom flashing I made to keep any water/snow/ice out of the roof assembly/decking.
Thanks for all the info!

 

[Hogwildz]

Thank you, gentleman.

Hog, you saying I can get by with just one extended roof brace? ...or do you mean both extended brackets attached to shingles side, rather than dilly with the top of the roof (flat top)?
Ther will be 6 foot of pipe above that drip edge flashing where the shingles meet the flat roof top.

The cut out at the eave has a custom flashing I made to keep any water/snow/ice out of the roof assembly/decking.
Thanks for all the info!

2 braces, the lower one you cut out the eave edge at, and one upper under the metal drip edge where the shingles meet the modified.

 

[Hogwildz]

Install the upper brace under the drip edge at the end of the arrow. No need to touch the modified roof. Save yourself the aggravation.

If you can hit rafters with the mounting bolts, do that. I don't trust mounting into plywood alone.

 

[Alexander L]

Ah... I see what you are saying, Hog.

There is already a wall bracket installed just under the cut out at the eave edge. I'll post a better pic to show that bracket.

So I assume you are saying to tuck the upper brackets under the drip edge flashing - as in to have the hex screws & bracket tucked under and hidden under that drip edge flashing... or did you simply mean just screw the upper bracket into the shingles/decking directly below the drip edge?

Don't mean to be a pain your info is much appreciated!
First snow of season hits tomorrow night... though, not much is going to stick.

 

[Hogwildz]

Ah... I see what you are saying, Hog.

There is already a wall bracket installed just under the cut out at the eave edge. I'll post a better pic to show that bracket.

So I assume you are saying to tuck the upper brackets under the drip edge flashing - as in to have the hex screws & bracket tucked under and hidden under that drip edge flashing... or did you simply mean just screw the upper bracket into the shingles/decking directly below the drip edge?

Don't mean to be a pain your info is much appreciated!
First snow of season hits tomorrow night... though, not much is going to stick.
View attachment 218274

Yes, tuck the mount feet up under the drip edge or as close to it as you can. You can snip a couple small tabs on the bottom of the drip edge, mount the bracket feet, then bent the tabs you cut back down over the bracket feet. Some urethane caulk can be used over the tab cuts to finish it off, may not even need it.
Or just mount the bracket as close to the bottom of the drip edge as possible(put urethane caulk under where the mounts meet to roof), and urethane caulk over the bolt heads.

How long are those pipe sections each?

BTW, you're not a pain. Keep asking questions until you feel comfortable with what you're doing.
That's why we are all here, to help each other.
Next time I'm in Cali, we get beers. ;-)

 

[Alexander L]

Got ya, Hog. Excellent.
Those chimney pipe sections are 3 footers. The pics in my original first post show three 3-foot sections above the tee. There will be an additional 5' of chimney pipe on top of what is pictured in the first pics. Makes for a total of 13' 6" of chimney pipe above the tee.
The Duravent instructions call for support every 4 feet... so two extended roof brackets will cover me, as there will be about 12' of freestanding chimney above the first wall strap support.

 

[Alexander L]

*Edit

My local Ace had Through the Roof. Awesome.
Thank you to all for the suggestions!
Back to it.

 

[begreen]

https://www.geocelusa.com/product-category/polyurethane/

 

[Alexander L]

Well, thanks to the fine members of Hearth.com (owe all of you tasty brews), I got some chimney and bracing up this weekend. Not finished (another two foot section and cap), but thought I would post some progress and thank bg, bholler, and hog for the advice. Thank you! Bracing is solid. Glad I didn't have to go into the flat part of the rooftop.

 

[begreen]

Looking good. I knew hog was the fellow to go to for roofing info. You'll be firing up soon.

 

[ajayabb]

Looks great

 

[Hogwildz]

You're hooked up. Get it done & fire it up!

 

[Rich L]

Hi all!
I am going to be bracing a length of freestanding chimney and I had a question about making sure I properly seal (silicone, etc.) the angle brackets/hardware that will be screwed down to the roofing.

There will be a total of 13' 6" of pipe above the tee. This will result in 5' of pipe above the roof.
I will be using two extending roof brackets to brace, so that the chimney is supported about every 4 feet.

The first set of brackets will affix to the steep shingled side of the roof. The second set of brackets for the upper extending roof brace will need to be screwed down to the top of the roof... which is a pretty flat. The roof top is torch down bitumen. I am concerned about the proper sealant for this flat portion of the roof, as snow will occasionally sit up there on the flat part of the roof. I want to seal under and over these brackets in a way that will not result in any leaks. I'm at 6000' in the SoCal mountains... so not uber amounts of snow.

Is 100% silicone the sealant that should be used for the angle brackets that are affixed to a flat-ish surface roof top? Something better? I figure that the pro installers will be able to give me some tips on which sealant works best. Appreciate any info/advice!

Pics:
View attachment 218249 View attachment 218250

Go to home depot.In the gutter section get a couple of tubs of Seamer Mate.This stuff is better than Geocel and through the roof.

 

[Alexander L]

Thought I would ask here, rather than create a new thread...

Will I be fine using an insulation (fiberglass) with a kraft paper facing in the wall behind where the stove will be? It will be fine regarding clearance to combustibles... just thought I would make sure. Seems like it should be okay.

I was going to stuff roux mineral wool insulation where it will actually contact the thimble.

Thank you for any insight!
Pic:

 

[bholler]

Go to home depot.In the gutter section get a couple of tubs of Seamer Mate.This stuff is better than Geocel and through the roof.

Geocel 4500 is better than anything else i have used by far including seamermate.