Metal roof and round metal chimney (stove pipe)

[rdzone]

Anyone install a metal roof on a cabin that has a round chimney/stove pipe exiting through the roof?  I have seen the install instructions for the metal roof.  They cover square masonary chimneys and round vent pipes, but not stove pipes (8-10 inch in diameter).  Any insights would be appreciated.  Thanks

Chuck

[kenhill]

Chuck, the Plumbing and Heating store where we bought our Oil Stove and Pipe sold us a type of vent flashing for our metal roof.  It is mostly rubber which fits around your pipe and is clamped with a "hose" clamp.  The base is very flexible and bends to  the contours of the metal roofing.  We applied a silicon caulk to the base and then used the regular roofing screws to screw it to the roof.  Done!  Ken

[Amanda_931]

sounds like what I needed a couple of years ago.

for one of those tubular skylights.

[JRR]

We haven't installed a woodstove yet, but our plan is to exit the wall, right on center, turn a ninety and go up thru the roof apex overhang.  That way sealing is not an issue.

[rdzone]

Thanks for the replies.  I knew there had to be something like you all described, it just didn't cover it in the install instructions.  I will go talk to my metal roof dealer.   I bought my metal roofing way early.  I was in buying my i-joists and someone had ordered 3 times what they needed, so I got a smoking deal.  I got denali green delta rib 36" wide x 24' long pieces (38) for about a $1 a foot.   It is normally closer to $3 a foot around here.   (alaska)  I still need to buy the trim, but that will be in the spring.  If I wasn't installing a masonary heater in the center of the building I would exit out the side.

Chuck

[glenn kangiser]

That's a real bargain, Chuck.

Note that even a normal tin roof jack will work for the chimney if a molded one is not available.  Put it under the top and over the sides and  bottom.  Sides may have to go under or over as works best with the ribs.  Flatten the ribs if necessary.   A good butyl sealant or silicone rubber used generously under all laps would be necessary.  Add support as necessary under where you make your cutout.  

The formed one would work best, but the tin one could be made to work with plenty of sealant and screws.

Hammer on top with heavy sledge held sideways underneath for a backer will help to flatten the bottom rib(s).  Done carefully you can make it look decent.  I just posted this in case you have trouble getting the molded one.

[MountainDon]

Good to know Glenn. For some reason I just don't like wall exits for chimney, if at all avoidable. I believe the stove draws better with a straight up run. I've had a self installed chimney thru a shingle roof for 22 years and it never had a problem. Today the roofing "experts" are installing a metal roof. They told me they're going to use a rubber-like seal.

[glenn-k]

I built about 300 steel buildings (with my crew) and sometimes we just had to do what we had to do.

Jacks that are made for it are the best, but there is almost always another way.

[kenhill]

Chuck, I bought my flashing at Central Plumbing and Heating in Anchorage, AK.

[rdzone]

Thanks for the replies. I called the metal roof manufacture in Anchorage and they told me they make the flashing kit.  They just need to know the type of chimney and the pitch of the roof and they can get me the right kit.  

Kenhill thanks for the heads up.  I have had good luck with Central Plumbing and Heating.

[Tennessee]

Hello Glenn,

Can you explain a little further on how to install regular tin flashing boot on a metal roof?  I have already explored the rubber boot option and from my research this is an expensive option.  I have a metal roof on a 12/12 pitch roof (the 20X30 cottage).  I have already purchased the 6/12 to 12/12 adjustable flashing for my chimney.  I am just trying to figure out how to install.  Any help would be appreicated.

Thanks

[glenn-k]

Hi Tennessee.   Welcome to the forum.  What I am describing is similar to how we do this on steel buildings.

I assume you are going to have to go over at least 1 or 2 high ribs.  I would suggest boxing the framing out under the roof opening to keep the strength around the cutout.

I will also assume that the jack is not as wide as the sheet.

Here is a sketch of what I would do on a metal building.

Caulk all areas between the jack and sheeting whether they be under or over.  Stitch screws about every 3 to 4 inches all around and as necessary.  Only the ends of the slit will be real critical for leakage if over cut.  If you are not happy with just caulking there , then the tin patch over the top with a screw or two can be used -- Even a screw there and caulked around would probably be sufficient if the slit has been carefully cut.  That one is up to you.

[MountainDon]

Well, I'm glad to see this solution Glenn. It seemed to me that was the way to do it, but beating the crap out of a brand new roof panel somehow didn't seem right. Perhaps fun and stress relieving.    I think when I do mine I'll wait until DW is away so she doesn't have to hear me beating up on her shiny new roof.

The "expert" roofers just finished the metal roof on our city home a couple days ago (just in time for the snowstorm) and I haven't been able to see what they did yet. It's been fun watching the snow slowly slide down the roof panels.

[glenn-k]

You just beat the crap out of it carefully, Mountain Don.

Note that this solution - flattening the ends in this manner, but with a machine is the way that some building companies seal the tops of the sheets on their buildings.  They actually come with pre-flattened ends from the factory.

[bartholomew]

One nice thing about having the chimney exit right near the ridge is that you can tuck that top slit Glenn mentions out of the weather under the ridge cap. Or you can do away with the slit altogether and just lap the top edge of the jack flashing with a second piece of flashing that runs all the way up under the ridge cap.

[glenn-k]

That is a real good point, Bart.  It will get you up to where 2 feet above the highest point 10 feet away won't mean installing guy wires and it won't get cleaned off the roof by sliding snow and ice also.  It would still be set on one side of the ridge.

Why didn't I think of that. :-/

[kenhill]

The Deck tight flashing for an 8 inch pipe is $82 which seems a small cost of the total heating system.  It has a rubber accordion style top that allows installation on any pitch roof and the base is flexible with a rubber gasket that you also use the silicon sealant on.  I did install mine so that it was near the peak, with the top part of the flashing under the ridge cap.  That way when the 3 feet of snow lets go, the chimney is not damaged.  We used perloins instead of decking so this was a quick way to go.

[tc-vt]

There is a flashing kit for installation of the preformed jack to a metal corrugated roof.  I had my building supplier order it from Selkirk, the maker of metalbestos.  The kit consists of two strips of sheet metal angle stock and a gasket.  It's probably not entirely necessary to use this but it is an item that's out there.  My building supplier had never heard of it before I asked for it.

http://www.selkirkinc.com/pdfs/install/platinum/0015212-Metal-Roof-Flashing-Kit.pdf

The rubber gasket kit is also available from them:

http://www.selkirkinc.com/pdfs/install/platinum/RubberbootInstructions0015215-012306.pdf

There is a lot of information on there about installation of these chimneys.:

http://www.selkirkinc.com/wholesale/catalog/Platinumchimney.htm

Tom

[Tennessee]

Thanks Glenn and everyone else for the good suggestion.  I will be less than 3 feet from the top of my flashing boot to the ridge cap.  Buying a piece of flashing that will be as wide as my flashing a get me up under my ridge cap may be the way to go.  I really never thought of this.  Thanks again.  

[glenn-k]

Glad we could be of help, Tennessee.  If you get a chance we we like to see pictures of your project and your sawmill.

[Tennessee]

I have tons of pics just not sure I would know how to post them.

[glenn-k]

Here is info on posting from the forum news section.  Just go to photobucket web site - upload them (digital pictures) then copy the IMG tag below the picture and paste it into your reply.

Photobucket will look at the file on your computer to copy it - you tell it which file same as looking for files on your computer.

http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1115032671