Masonry Chimney Clearance Old House

[shorthill]

I have an old house that has a brick chimney that has an old masonry liner in it and a newer stainless steel liner. There is an old woodstove in the basement (Fisher Papa Bear) and the masonry chimney extends up through the middle of our house. There is a joist and beam that touch the masonry chimney above where the stove pipe attaches to the chimney that I can see and I imagine that there is more framing that is directly against the chimney that is hidden behind walls and/or floors as the chimney goes through the first and second floors and roof. I came across information that a 2" air gap is required now between masonry chimneys and framing but I guess that is not something they worried about in the old days. My question is this, should I be concerned about burning a fire in the wood stove?

 

[pen]

It's definitely reason for concern. Appliances installed properly don't cause issues. You found something out of line and it's worth investigating.

Do you know if there is an insulation blanket installed around this liner? Do you have the sweeps name that installed the liner, or was it a homeowner job?

If you were to know who did the installation, it wouldn't hurt to give them a call and see what they have on file. The chimney should have been well swept first before the liner was installed. An insulation blanket will help provide an extra layer of protection if clearances are close, but the system should have been cleaned first.

Is there much masonry between this joist and the flue itself? Has a sweep looked at this? Have any pics to share?

Welcome to the site.

pen

 

[shorthill]

The ss liner was a homeowner job, chimney was swept first. There was not room for a insulation blanket so the perlite/cement mix was used. A sweep gave the advice to replace the liner and use perlite (and sweep, etc.) but did not mention the framing.

I have not had a sweep come to look at it yet, wanted to see whether it is an issue first (haven't been using the stove, want to make sure it is safe).

The ss flue has a terra cotta chimney liner and then the 4" brick and then the beam and joist. The beam is against the brick and the joist almost touches, the other joist and cross piece have an air gap of about 1". I put in pictures that shows the joist and the beam.

Thanks for the advice.

 

[chimneylinerjames]

This does not look like anything to worry about. A SS liner with proper insulation and 4" nominal masonry, such as a brick has a 0 clearance rating. Plus you have flues inside the chimney. Nothing to worry about. This is a very commonly seen inside homes. Consider yourself safe with the chimney liner.

 

[oconnor]

Likely a non issue. Some liner systems will give you a zero clearance rating from the brick to adjacent combustibles when they are insulated per instruction. That is what I had to do with mine. Many beams like the one you picture behind walls etc.

 

[bholler]

well yes most liners with proper insulation give you zero clearance with 4" moninal masonry between. my question is if you didn't have room for insulation blanket how did you get 1" of pour in insulation around it which is what most liners require for zero clearance?. the old clay should have been taken out to allow for either wrap or proper pour in insulation.

 

[rwhite]

well yes most liners with proper insulation give you zero clearance with 4" moninal masonry between. my question is if you didn't have room for insulation blanket how did you get 1" of pour in insulation around it which is what most liners require for zero clearance?. the old clay should have been taken out to allow for either wrap or proper pour in insulation.

I installed 1/2" insulation on my liner. Once you get the blanket and mesh screen on it get pretty thick and hangs on everything. I would think it would be easier if you had a tight fit to get an 1" of perlite in rather than a 1/2" blanket.


To the OP: You could give yourself piece of mind by sticking a meat thermometer in between the joist and brick and monitoring the temps.

 

[tcassavaugh]

burn it....enjoy the stove.