Wood Insert into Half-Masonry Fireplace?!

[kcmetzy]

Hi everyone!

I've been lurking around here since I discovered we have a big problem and thought ya'll would be able to help us out.

We are building a new house and did not build a full masonry fireplace. The house is currently being built, but a full masonry fireplace is not an option anymore. We purchased the Osburn Matrix wood insert online several months ago (not a ZC unit), and just now realized it was for a full masonry fireplace (rookie mistake.) It can't be returned.

Anyway, with that said, my husband is DETERMINED to make this work. Is it possible to build the firebox area of solid masonry with triple wall stainless steel flue pipe to make this a SAFE construction?

He said he is constructing a masonry firebox according to the international building codes found here:
http://www.rumford.com/articlefireplacecodes.html

The sides and back of the firebox will be constructed with hardi board, followed by cinderblocks, then 4 inches of solid concrete blocks for a total of 8 inches. The bottom will be the same (minus the hardiboard, we have a slab foundation) On top, he plans to use angle iron to support for 4 inches of solid concrete. He is going to use single wall black pipe from the stove to the roof support (inside the firebox area), then once it is outside of the firebox, it will be triple wall stainless steel pipe. All mortar is heat resistant.

I am probably describing it all wrong, he's not here to tell me exactly what he's doing, but hopefully I've given you enough info to give you an idea of what's going on. In a nut shell, a completely enclosed masonry fireBOX, with triple wall stainless steel liner through a wood chase. I've never heard of that before. It's usually either prefab or full masonry, not a combo.

He makes it sound like if anything, what he's doing is overkill, but I'm not easily persuaded. In Australia, they sell this unit with an optional zero clearance kit. My husband says what he's doing is MUCH better than what this kit could offer:

http://www.osburn-australia.com/upload/documents/manuels/45649A_05-09-2014.pdf

And I have to agree, the kit doesn't look like much, and it's not available to us in the U.S. (trust me, I've tried), but I struggle with doing something that is outside the norm. Would love to hear all input, good or bad, from you guys.

Thanks a lot!

Kristen

 

[begreen]

First concern with the weight of the masonry is that it lacks a proper foundation. This could be disastrous if the earth is soft beneath the slab in that area. As described it is not a masonry fireplace. It would be safer and probably more cost effective to sell the Osburn and get a true ZC fireplace.

 

[Hogwildz]

I don't see why you can't build a box out of non-combustible materials with a chase for the stack, and install the insert in that.
As long as the clearance to combustibles is observed and met, why not?
Steel studs with Durock, then cultured stone, tile whatever over the Durock.

 

[begreen]

I'm not saying it won't work, but it's untested and uncertified. The results are unknown due to a lot of factors including the quality of construction. For example, the suggested hardibacker is made with cellulose fiber filler.

We are only going to have opinions here. When in doubt ask your inspector and insurance company first and then the stove manufacturer. If they say ok, get it in writing.

 

[Grisu]

Totally with BeGreen. The local building code authority, the home insurance and Osburn (SBI) will be the ones who need to sign off on that idea. You can try but I would not get my hopes up too much. Woodburning units that reach temps of 700 F+ during regular operation are nothing to be taking shortcuts with.

Best solution, IMHO, will be to sell the insert and get a freestanding stove or an EPA-approved zero clearance fireplace. If money is tight right now you can get a solid budget stove like an Englander or Drolet for less than $1000 and upgrade to a less utilitarian looking model in a few years.

 

[dafattkidd]

Like hog said I'm sure you could make it work in a safe and aesthetically pleasing way. If you're in the middle of a large construction project I can only assume you will have inspectors on site at some point, so that could be an issue. The other problem with making this work without the full masonry fireplace, and without the ok of SBI, the inspector and your insurance company you expose yourself to liability if God forbid you need to make an insurance claim.

I bet you can sell the matrix for a decent amount. Probably the most cost effective solution is Grisu's solution: install a $1000 free standing stove with a proper install and sensible location. Use the sale of the Matrix to offset the cost of hearth, stove and chimney set up.

Whatever unit you go with, how's your wood supply? These units require good dry wood. Good luck!

 

[kcmetzy]

Thanks guys for taking the time to respond.

A free standing or zero clearance unit would probably be the smartest choice, but my husband is pretty set on making this work. We have spoken with Osburn, but unfortunately they were very quick to say that it is only for a full masonry fireplace and wouldn't entertain the idea of anything but. I understand it's a liability thing, but not sure how constructing the firebox in the way I described would be any less safe than a zero clearance approved wood stove. But I agree, getting the manufacturer, insurance, and inspector on the same page sounds like an impossible task.

I'll keep you guys posted on the final outcome!

 

[begreen]

OK, the issue here is not a question of installation. It is of a hubby that won't admit a mistake and change course. It's not that this can't be done, but that there is no endorsement or testing to approve this method. New home building is stressful. I would advise letting this one go and do it right. There are too many other decisions that need to be made during the course of construction. Stick to doing things right as a step toward getting the final certification for occupancy.

 

[dafattkidd]

Thanks guys for taking the time to respond.

A free standing or zero clearance unit would probably be the smartest choice, but my husband is pretty set on making this work. We have spoken with Osburn, but unfortunately they were very quick to say that it is only for a full masonry fireplace and wouldn't entertain the idea of anything but. I understand it's a liability thing, but not sure how constructing the firebox in the way I described would be any less safe than a zero clearance approved wood stove. But I agree, getting the manufacturer, insurance, and inspector on the same page sounds like an impossible task.

I'll keep you guys posted on the final outcome!

I work for a builder. We build custom high end homes. We see mistakes like this all the time. Generally, it is a shared loss between the homeowner, us (the GC) and the vendor involved. Everyone complains about it, then moves on. Errors like this are practically budgeted for at the onset of construction. In this case it is barely a loss. In fact, it sounds like a net gain. The amount of money saved by not building a full masonry fireplace will offset all other costs involved in installing a free standing stove. The opportunity to sell the Matrix for slightly below retail makes this mistake even less offensive. Considering all of the moving parts involved in new construction this is barely a blip.

Building a fireplace around an error that could potentially cost you hundreds of thousands of dollars in loss seems hardly worth it when considering the amount lost on a matrix will be a few hundred bucks. Not to mention even if you are successful at building it safely, getting a c of o and maintaining homeowners insurance, you will have to remedy this before selling the house down the road.

Anyway, Good luck with whatever you do. You came here seeking advice. You are getting very good advice from an experienced group of individuals with a variety of backgrounds and good intentions. My advice to you is to show this thread to your husband, and agree together how to proceed.

 

[kcmetzy]

I think we've decided to get a zero clearance wood insert to be sure we don't have problems down the road with insurance, inspections, etc. That being said, any info on a good zc wood insert that has a contemporary front? That's what I loved about the matrix.

I realize since everyone is telling me I'm dead, that I should just lie down, but I do have one more question. Have ya'll seen anything like this?

http://www.woodlanddirect.com/Firep...places/36-Engineered-Masonry-Fireplace-System

I spoke with the gentleman at woodland direct and he assured me that this would work for our current situation. Do ya'll have any experience with this? It was would a pretty costly remedy, and I highly doubt we will go this route, but just curious what you think. It's basically what my husband wanted to build (or has built, but won't be using), but UL approved.

Your input has been very valuable. Thanks so much for the advice.

 

[bholler]

I dont see why that would not work but it is $2000 add that to the price of your insert and i bet you could sell the insert and get a good zc for less but i am not sure on that

 

[Grisu]

Take a good look at the Pacific Energy FP30. That has a very similar outside design as the Matrix. The advantage of many ZC fireplaces over a fireplace insert like the Matrix is that you can often add additional ducting to transfer heat to other rooms.

Just a random sampling of other EPA-approved ZC fireplaces/manufacturers:

Superior fireplaces (by Lennox): http://superiorfireplaces.us.com/products/t/superior-wood-burning-fireplaces (look for the EPA-approved ones)
FireplaceXtraordinaire
Napoleon (e. g. NZ3000)
Quadrafire 7100
Northstar: http://www.heatnglo.com/Products/North-Star-Wood-Fireplace.aspx
Regency Excalibur or R90
Valcourt: (broken link removed to http://www.valcourtinc.com/en/heaters/high-efficiency)
Osburn Stratford/Flame Monaco
Hearthstone Montgomery
Kozyheat Z42