When I bought my stove the guy in the shop told me the best thing to use was rigid SS liner. 5.5 metres total, 4 metres of which is inside the chimney and the other 1.5 metres outside. He said just go around it with mortar at the top of the chimney to seal it. Anyway it doesn't rain here very often but when it does it's heavy and some rain leaked down around the pipe. I went up and sealed it with plenty of high temperature silicone but a few days later found the silicone was only attached to the SS pipe and no longer attached to the mortar. Then yesterday I got up there for something else when the fire was burning and noticed that the pipe expands a full 3/4" when hot. How should I deal with this expansion and still have it waterproof? Was it wrong to use rigid pipe?
Fires of passion causing unexpected inflation of rigid member
- Thread starter bokehman
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ask the guy you bought the pipe from & see what he has to say about it.
Maybe someone here knows the cure, I sure don't.
So if you know,chime in please.
Just a last resort thought. transistion to 6 in black steel stove pipe just below where you need to make the seal, and use high temp stove morter to seal the joint. maybe the 6 inch black stove pipe wont expand & contract, but maybe it will.I dont know.
I do know that when something don't work ,you need to try something different to get a different result.
I am not a pro on this, you need to talk to someone who knows more than me.
Maybe someone here knows the cure, I sure don't.
So if you know,chime in please.
Just a last resort thought. transistion to 6 in black steel stove pipe just below where you need to make the seal, and use high temp stove morter to seal the joint. maybe the 6 inch black stove pipe wont expand & contract, but maybe it will.I dont know.
I do know that when something don't work ,you need to try something different to get a different result.
I am not a pro on this, you need to talk to someone who knows more than me.
bokehman said:
Now the serious Bok. You have materials of different coefficients of expansion, particularly with high deltas ( temp differencial ).
Search the Selkirk Metalbestos ( one example ) site for "finishing" methods and devices to prevent water seeping down the metal liner. One method is a conical cap that fits around the SS pipe just above the roof. It clamps onto the pipe, and is sealed to the pipe with flexible silicone caulk. We've used this method in Matalbestos SS pipe stand alone construction, and rigid SS liner in a stone chimney with a mortar covering. You'll never completely waterproof seal a mortar to metal joint without some kind of fitting to account for the difference in expansion when burning.
Hope this helps.
mayhem said:
Sure is one way to get people will read his thread. I was sure it would end up in the dreaded Ash Can right below thread here yesterday on glass cleaning with urine....For those of you who missed that one - it got very interesting.
Me thinks some of us have been cooped up too long in this cold snap....
perplexed said:
Oh myyyyy---you boys need a Time Out. Now, getting back to glass cleaning solutions...............
3/4 of an inch seems like a lot of expansion to cover with high temp silicone, but I'd just try using more. how easy is it to get on your roof? might require more than one application. By the time you figure out that this won't work it will be summer and you'll have several months to get it fixed, lol.
Use the standard storm collar on the rigid section and be sure that the concrete chimney crown is sloped away.
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