Rookie Questions

[Mike]

Found this forum, looks perfect, lots of info... I've done lots of research but still a lot of questions. ... hope I can benefit from your experience...
I want to install a Hampton insert in my solid masonry fireplace.
Facts:
-2 story central plan house built in late 20s, solid brick, external chimney about 30', living room fireplace about 450 sqft., not open concept but generally open first floor
-existing 16" hearth over std cement pad built on basement joists, etc.
-spoke with various vendors (WETT certified in Canada), contractors, masons, an architect, insurance agent, and the local building dept.
-looked at many inserts. The contenders were Kennebec, Clydesdale, and Hampton. Settled on Hampton.
- Have obtained and reviewed relevant sections of NFPA 211 (not applicable here), CSA B365, and Ontario Building Code
-looked at various fireplace finishes.
- Bldg dept say I need a permit. After sending me through 3 people, finally got someone who knows a bit but did not know what an EPA fireplace was and said we don't get too many of these permit requests (in a major Cdn city). Frankly this baffles me. All others (except the architect) said forget the permit. Proposed WETT installer also recommends I don't get permit based on his experiences. I believe in getting a permit but it appears to be a real challenge on all fronts.
- The Hampton meets all combustible clearances but the only problem is that the firebox depth is too short by 1.5".
Questions:
1) Facing / Surround: If the fireplace front is built out to meet the required depth, will this work from a form and function perspective? I am told that durock sheeting overlain on the existing tile face and then 1.25" granite slab face (my choice but $$$) will be OK. Granite vendor says there can be no gap behind it to prevent cracking. Should Micor or alternate be placed behind the durock?
2) Hearth: Will have to extend to about 25" from existing face to meet the 18" local requirement and accomodate distance from Hampton firebox door. If Micor is placed (glued) first, then durock (tapcon screw) sheet, then a granite slab (all over a 3/4" oak tg floor on std sub floor) will this work structurally to prevent granite slab cracking if kneeling on it? This is a 9" extension from the existing hearth. Note Micor will surpass the R=0.6 specified by Hampton.

Thanks for your assistance.

 

[seaken]

Hello, and welcome.

You are doing the right thing in getting the professional opinion of WETT and other contractors. But bear in mind that the local authority whoever is appointed by your city to enforce the building and/or fire safety codes. If the manual of the insert says it needs a hearth with 0.6 R value then I question whether your existing hearth can simply be extended. You will probably need to completely replace the hearth extension.

As far as extending the face of the fireplace, yes, that should work ok. However, make sure your outlet collar clears the new depth of the lintel area or that you can install an offset box that is acceptable to the local codes.

Then permit issue if often an area of trouble. If I were you, I would try very hard to get the permit and have the building inspector sign off. But, that is sometimes easier said than done.

Sean

 

[Marcus]

I live in a suberb of a major city and our local building inspector had never heard of a fireplace insert. When I brougt him all the manuals and specs he seemed not to care what I did as long as it was built into the existing fireplace. He didn't even care who was installing it.

 

[seaken]

I live in a suberb of a major city and our local building inspector had never heard of a fireplace insert. When I brougt him all the manuals and specs he seemed not to care what I did as long as it was built into the existing fireplace. He didn't even care who was installing it.

This happens sometimes with inserts. Some code officials mistakenly think the fireplace is enough to contain anything put into it. In reality, the fireplace was never intended to accept an insert and there are new codes that address the temperatures and other conditions that the insert introduces. You can't fight city hall. Make sure you follow the manufacturers instructions and document it. Your insurance company may want you to prove that what you are doing is approved.

Sean

 

[Mike]

Thanks for the replies so far. Insce agent is not concerned with permit approval, only wants a copy of the WETT installer's certification that it was installed to code by a WETT installer. Re rebuilding entire hearth extension, why would this be necessary if Micor is at R=1.1 or so when Hampton spec is R=1.1 (I wrote the wrong spec earlier) for floor protection (pg 7 of last year's manual specs out hearth thickness of 0.5" with k value = 0.84", R value=0.6 or >. Also... "Floor protection must be non-combustible, insulative material with R value of 1.1 or >.) My thinking is the granite on top of the durock on top of the Micor will work for the hearth / floor protection ... am I missing something??? How about structurally, is the 1.25" granite slab hearth likely to crack when on the durock/micor combo?

Micor behind durock on the facing? or no Micor necessary? I looked into the offset with new lintel depth and should work but will review again. Note there is no new structural metal lintel in this setup, only the micor/durock/granite slab face in front of the existingl lintel, so the new face surround would be 2.25 inches with micor and 1.75 without. Either way the Hampton depth requirement will be met....am I missing something again?

Re building permit, I have nothing but respect for the process but was baffled on this one. The counter person told me I need a mechanical and HVAC permit. I nicely and persuasively asked to speak to an engineer. This was the final one who came out and dismissed the other permits and focused on the homeowner undertaking type of permit (can't recall name) and specced out the 2/10 rule. While I know this is a code req. it surprised me this was the focus as my thinking is the EPA insert should pose less of an issue for 2/10. But the rules are the rules.

Note the all vendors / installers spoken to tell me I am really complicating matters by trying to do the right thing. I know several people who have installed stoves, etc and none have gotten a permit....Seem to be alone on this.

Thanks again.

 

[seaken]

Thanks for the replies so far. Insce agent is not concerned with permit approval, only wants a copy of the WETT installer's certification that it was installed to code by a WETT installer. Re rebuilding entire hearth extension, why would this be necessary if Micor is at R=1.1 or so when Hampton spec is R=1.1 (I wrote the wrong spec earlier) for floor protection (pg 7 of last year's manual specs out hearth thickness of 0.5" with k value = 0.84", R value=0.6 or >. Also... "Floor protection must be non-combustible, insulative material with R value of 1.1 or >.) My thinking is the granite on top of the durock on top of the Micor will work for the hearth / floor protection ... am I missing something??? How about structurally, is the 1.25" granite slab hearth likely to crack when on the durock/micor combo?

Micor behind durock on the facing? or no Micor necessary? I looked into the offset with new lintel depth and should work but will review again. Note there is no new structural metal lintel in this setup, only the micor/durock/granite slab face in front of the existingl lintel, so the new face surround would be 2.25 inches with micor and 1.75 without. Either way the Hampton depth requirement will be met....am I missing something again?

Re building permit, I have nothing but respect for the process but was baffled on this one. The counter person told me I need a mechanical and HVAC permit. I nicely and persuasively asked to speak to an engineer. This was the final one who came out and dismissed the other permits and focused on the homeowner undertaking type of permit (can't recall name) and specced out the 2/10 rule. While I know this is a code req. it surprised me this was the focus as my thinking is the EPA insert should pose less of an issue for 2/10. But the rules are the rules.

Note the all vendors / installers spoken to tell me I am really complicating matters by trying to do the right thing. I know several people who have installed stoves, etc and none have gotten a permit....Seem to be alone on this.

Thanks again.

"existing 16” hearth over std cement pad built on basement joists, etc."

This is where I question the R-value. Cement by itself has a a low R-value. You may have enough depending on it's thickness. If you have the room you can avoid trouble my overlaying the Micor over the existing hearth as you extend the hearth. I can't tell from here. I am just bringing it up as a possible problem.

I don't think you need the Micor on the fireplace surface. Just mortar. Make sure the joint is sealed between the existing face and the new materials.

I hear you about the permit. It sounds like standard practice in your area is to not use permits. Just make sure you install it correctly and provide what the insurance company needs.

Take care,
Sean

 

[Mike]

Thanks Sean.

This permit is a moral dilemna for me in terms of doing the right thing......anyone else gone through this? I did a thread search but didn't find too much. I think if I were in the bldg dept, i would be doing a whole lot to educate myself on this with the price of gas etc going up. More people are going in this direction, I know the installers are busy.

It sound like a tight mortar seal is sufficient for the face. Any experieince with laying slab on durock? The granite would be expensive and I would gag if I had to replace it.