Chimney sealing

[Tscarborough]

Re: Chimney sealing

You need something flexible as the final seal.

[sjdritz]

Re: Chimney sealing

Tscarborough,
Would this work?

DuraVent 9650 8" Class A Chimney Pipe Adjustable Roof Flashing 7/12-12/12

With a storm collar also?

Thanks,

Scott D

[Tscarborough]

Re: Chimney sealing

That is to flash the pipe on the roof, you still have the issue of no roof and the actual seal around the pipe. It sounds like the high temp silicone can take the heat, so just tile to it and use that.

[sjdritz]

Re: Chimney sealing

Tscarborough,

What do you think of this stuff?

Rutland Fire Clay Company - Stove, Chimney, Fireplace maintenance and Hearth Repair Products.

Thanks for your help,

Scott D.

[sjdritz]

Re: Chimney sealing

Or this stuff?

Rutland Fire Clay Company - Stove, Chimney, Fireplace maintenance and Hearth Repair Products.

Scott D.

[Tscarborough]

Re: Chimney sealing

I like 800 degrees better than 550-600.

[sjdritz]

Re: Chimney sealing

Even though it is not silicone?

[Tscarborough]

Re: Chimney sealing

It sounds like it is designed for the specific purpose.

[david s]

Re: Chimney sealing

I've not tried the "Seal it right" product so can't really comment, but I have tried a few different types of sealant and found the high temp RTV silicon the best. Other types go hard and lose their adhesion to the surfaces while the silicon sticks and remains flexible.I use a Dow product that is not as highly temp rated as the silicon product you found from Rutland. Mine gets quite soft when it's really hot but does not burn or go hard.The higher the temp rating the more expensive (expotentially) the stuff is, also the really high temp stuff contains carcinogens.Check out motor accessories shops, they usually stock the stuff in smaller tubes too. Shop around, but I think the product you've found is highly suitable.

[luca]

Re: Chimney sealing

I just bought a similar (double insulated) chimney and noticed that you can buy a trim collar from the manufacturer (mine is a Selkirk). Even without the collar, it is unlikely that the outside of the chimney will get super hot--you can test it with a couple hot fires--so that you could simply caulk it with an appropriate outdoor/Silicone product.

[david s]

Re: Chimney sealing

Yes, but Scott is trying to get away with using a single wall flue pipe not a double.

[sjdritz]

Re: Chimney sealing

What about a solid 1-2 inch ring of this stuff

Rutland Fire Clay Company - Stove, Chimney, Fireplace maintenance and Hearth Repair Products.

surrounding the base of the pipe to the cement board?

Scott D.

[david s]

Re: Chimney sealing

Castable refractory is not flexible, weather will still get in between the pipe and the castable. The will be expanding and contracting way more than the castable, so you need something flexible there.

[david s]

Re: Chimney sealing

Scott,
You could try surrounding the pipe with some cardboard and make it about 1/8" thick, then use the castable around it, slide out the cardboard when the castable has set (24hrs) then fill the gap with high temp silicon. Cover the cardboard with plastic for easy removal.
After buying the castable and the high temp silicon it will probably be more expensive than fitting an extra outer flue.

[sjdritz]

Re: Chimney sealing

David,

That is what I was thinking of doing. A double wall pipe is $150.00. If I purchase that, what other options do I have? Would I just need the silicone and then I could tile right up to the pipe with the double walled?

Scott D.