hearth on hardwood floor

[paman77]

Hi, I’m looking for suggestions opinions from members on this forum.

I’m going to build a stone veneer enclosure for the Harman p35i insert from the floor to the ceiling. I have a few challenges along the way, currently the space where the insert/enclosure will go is hardwood floors so to build the hearth I was originally going to just put two ½ cement boards on top of the hardwood and use thinset/screws, after going research I came to the conclusion that this will not work. Some sites suggest putting down plywood over the hardwood floors and placing the cement board over that, which I’m not sure its going to be any better.

Which leads me to the following idea, I’m going to raise the hearth off the hardwood floor using 2x4’s, basically making a box out of that and installing my plywood/osb and then the cement board. My question is, will this help eliminate the shifting that otherwise would occur with the cement board right over the hardwood floor? Is this a safe reliable method to accomplish the hearth over a hardwood floor without cutting the floor out?

The other issue is when I fame using 2x4 should I lay down some plywood and build the framing over that or can I nail the 2x4 framing board directly to the hardwood floors? Mind you I will be fastening the framing to the wall studs and ceiling joists and hopefully the floor joist going through the hardwood floors.

I really don’t want to make more work for me by cutting out the floors and I’m thinking elevating the hearth might save me work although im not sure if I can nail the frame directly on the floor itself.

Any suggestions is greatly appreciated.

p

 

[edyit]

i built my hearth out of 2x framing with the plywood then durock on top of that and i'm sure quite a few others have done the same. i've yet to have an issue with it, just be sure to use enough durock to meet the R requirements of your particular stove.

 

[edyit]

sorry for the double post, but when you say enclosure what exactly do you mean? is your insert unit going into an existing fireplace or are you building around an insert, i'm not sure the latter is a good idea

 

[paman77]

sorry for the double post, but when you say enclosure what exactly do you mean? is your insert unit going into an existing fireplace or are you building around an insert, i'm not sure the latter is a good idea

I'm building my own around the insert out of 2x4 with cement board and stone veneer. I have engineer working on plans to help with the load.

anyone else have experience with building on top of existing hardwood floors ?

 

[Heatsource]

sorry for the double post, but when you say enclosure what exactly do you mean? is your insert unit going into an existing fireplace or are you building around an insert, i'm not sure the latter is a good idea

they do offer a ZC cabinet kit for the p35i
Zero Clearance Cabinet
1-00-774257 Zero clearance cabinet kit (not assembled)

 

[paman77]

they do offer a ZC cabinet kit for the p35i
Zero Clearance Cabinet
1-00-774257 Zero clearance cabinet kit (not assembled)

yes but im going to enclose the hold thing from floor to ceiling and i might as well just frame it out using 2x4. just not sure if i can frame it over hardwood.

 

[begreen]

You must use the zero-clearance enclosure if there is no existing fireplace. Otherwise this can not be put into a framed enclosure. A cement board clad wood framed enclosure is a newly constructed chase. It does not qualify unless the appropriate, matching ZC enclosure is used.

page 6 :
This appliance may only be installed into an existing masonry or manufactured wood-burning fireplace or using the optional zero-clearance cabinet to build into a newly constructed chase.

 

[Heatsource]

yes but im going to enclose the hold thing from floor to ceiling and i might as well just frame it out using 2x4. just not sure if i can frame it over hardwood.

I dont see why you couldn't.... but i'm no carpentry/framing expert

 

[paman77]

You must use the zero-clearance enclosure if there is no existing fireplace. Otherwise this can not be put into a framed enclosure. A cement board clad wood framed enclosure is a newly constructed chase. It does not qualify unless the appropriate, matching ZC enclosure is used.

page 6 :
This appliance may only be installed into an existing masonry or manufactured wood-burning fireplace or using the optional zero-clearance cabinet to build into a newly constructed chase.

I'm going to look more into this, i was under the impression that if i used cement board to make the enclosure i would be ok.

 

[begreen]

For cement board to be ok Harman will have to had tested with that configuration in order to get This type of installation certified and UL approved. That seems unlikely, but if you can get it in writing from them so that the inspector and insurance underwriter have verification, then it may fly.

 

[begreen]

Moving thread to the Pellet forum

 

[paman77]

For cement board to be ok Harman will have to had tested with that configuration in order to get This type of installation certified and UL approved. That seems unlikely, but if you can get it in writing from them so that the inspector and insurance underwriter have verification, then it may fly.

can the zero clearence cabinet be installed over the hardwood

For cement board to be ok Harman will have to had tested with that configuration in order to get This type of installation certified and UL approved. That seems unlikely, but if you can get it in writing from them so that the inspector and insurance underwriter have verification, then it may fly.

can the zero clearance cabinet be installed over the hardwood or does the hearth need to be raised ? it doesn't really say.

 

[begreen]

The hearth extension just requires a noncombustible material. What will be used for the hearth extension?

For peace of mind maybe install the ZC enclosure on top of a sheet of cement board that extends out to the required hearth extension depth. Leave it raw under the ZC enclosure and tile the exposed hearth extension. This would be ok to install onto the hardwood.

 

[paman77]

The hearth extension just requires a noncombustible material. What will be used for the hearth extension?

For peace of mind maybe install the ZC enclosure on top of a sheet of cement board that extends out to the required hearth extension depth. Leave it raw under the ZC enclosure and tile the exposed hearth extension.

I'm going to email harman and see what they say. thanks for all the feedback so far.

 

[begreen]

Good plan.

 

[Harman newbie]

Hi, I’m looking for suggestions opinions from members on this forum.

I’m going to build a stone veneer enclosure for the Harman p35i insert from the floor to the ceiling. I have a few challenges along the way, currently the space where the insert/enclosure will go is hardwood floors so to build the hearth I was originally going to just put two ½ cement boards on top of the hardwood and use thinset/screws, after going research I came to the conclusion that this will not work. Some sites suggest putting down plywood over the hardwood floors and placing the cement board over that, which I’m not sure its going to be any better.

Which leads me to the following idea, I’m going to raise the hearth off the hardwood floor using 2x4’s, basically making a box out of that and installing my plywood/osb and then the cement board. My question is, will this help eliminate the shifting that otherwise would occur with the cement board right over the hardwood floor? Is this a safe reliable method to accomplish the hearth over a hardwood floor without cutting the floor out?

The other issue is when I fame using 2x4 should I lay down some plywood and build the framing over that or can I nail the 2x4 framing board directly to the hardwood floors? Mind you I will be fastening the framing to the wall studs and ceiling joists and hopefully the floor joist going through the hardwood floors.

I really don’t want to make more work for me by cutting out the floors and I’m thinking elevating the hearth might save me work although im not sure if I can nail the frame directly on the floor itself.

Any suggestions is greatly appreciated.

p

i have the same stove and problem you had. Longleaf pine floors in room where stove was. I used the zero clearance cabinet and just ran straight out the back. The hearth i used a piece of soapstone with felt pads underneath as not to scratch the flor. I did this just in case i ever had to remove the stove , the floor would be not marked up. Hope this helps

 

[bags]

Your main issue here is meeting code requirements and fire protection. The hardwood floors can take cement board screwed directly to them and then tiled without shifting if properly screwed off and installed along with the tile / stone or finish. That said, you can also build a 2X hearth above said existing hardwood floors and plywood / OSB that with cement board and tile too. This is the least of your issues on your project.

The main issue is meeting clearance to combustibles etc; I kind of follow what you are saying you are wanting to do but your have to meet your minimum clearances and such. You might want to do some reading over in the wood stoves section here on what options are out there to shrink clearances etc; There is many thing you can do like having a 1 inch space between combustibles and the tile or stone wall. Basically like a 1" air gap between the two.

Keep in mind though these are ideas and options. Bottom line is you need to meet whatever requirements your P35 has. Like hearth size and R rating, distance from corners, sides, front, and back. I think what you will be better off with is the zero clearance box for your stove and then build what you want accordingly.

That said, we all want to get creative and save money. I get that. We all do. When burning wood or pellets basic safety requirements must be met. This is for safety #1 and also being able to satisfy insurance co.'s and that damn inspector.

There is more than one way to skin a cat so to speak. You probably can come up with a scenario or build that would satisfy all requirements. I go outside the box all the time but I also will not cut corners and put myself nor anyone else in a possibly dangerous situation. You could design up what you intend or plan on doing and run it by an engineer and / or inspector. Likely the inspectors will go with whatever and engineer will slap his stamp on as that eliminates the inspector or building department from liability issue but they will still want codes followed as well.

I am a design build contractor and have done many outside the box type things. But it has to be safe, it has to pass codes and inspections, and it has to work. The sky is the limit as long as someone is footing the bill. Do some research and looking around for alternative solutions. There may be some or not. Also see what the ZC box costs and weigh that vs. all the time, hassle on and on to see what it is worth to you.