Decided to build my own hearth pad

[cleuci]

I've decided instead of buying one of those prefab hearths I'm going to build my own. Too expensive for the prefabs. I have a question about the design and I'm hoping someone can help. I have a Jotul Oslo 500 and the manual states I just need to have a UL1618 Type 1 Ember protected floor. I have carpet there now so I'm going to cut it out and I'm hoping I can just get away with putting a 3/4" piece of plywood, then a layer or two of durarock then either tile or slate stone on top of that. Is that adequate for this stove based on the info I gave you? Don't want too much height i'm okay with 1.25"-1.5" thick hearth but that's about it.

 

[tarzan]

I believe 1/2 inch Durok next gen has an R value of .39, that should be more than is required for your install.

 

[cleuci]

So in theory I can simply put the 1/2" durarock next gen on top of my base floor then tile or slate on top? That would be as easy as a tile job!

 

[xman23]

Try Google UL 1618 PDF. Sometimes you will find a free copy out there. I think ember protection is the easiest, fire proof material. That was one of the nice things about the Oslo. Don't they have two legs lengths? Do you need the six inch like mine. I layed down wire mesh on plywood then mud job the 2 inch cultured stone with a limestone border.

 

[srbellis]

Check this link out. It has an R value chart.

https://www.hearth.com/econtent/index.php/articles/hearth_design

 

[cleuci]

thanks xman, yeah they do have 2 different lenghts. I have the longer on mine. I think the shorter is used for tucking it in an existing fireplace. srbellis thanks that article has alot of info will read.

 

[begreen]

You are fine for an ember protection only hearth.

 

[Warm_in_NH]

Don't believe the oslo calls for an "r" value on the floor, just ember protection.

Key is the cement board so that if the grout or tile cracks and an ember gets through, there's another layer of non combustible material.

I'm making one for the same stove right now. Using 3/4" plywood w 1/2" dura rock and 3/8" tile on top of that. End up being about 1.5" total going to border it with oak stained to match the floor.

 

[srbellis]

i am in the middle of my own project. 18 guage metal studs with 2 layers of durock then tile and a stone veneer wall i'll post pics soon

 

[cleuci]

Warm in NH i must be close to you as i'm in concord. I can't decide if i want to go flush with existing carpet or slightly raised like your doing. Will hit HD tomorrow and see if i find any flooring material i like

 

[tarzan]

I know you stated you would like the hearth to be close to floor level but you should give some thought to the benefits of raising it a little.

I just built a hearth after years on the back burner. It came out to be 6" off the floor and I've got to say that little bit makes it much easier (for me anyway) at loading time.

 

[cleuci]

My issue is my baseboard heater is staying so i could raise maybe 1/2" and still tuck under but not much more than that. Will have to see what looks better

 

[cleuci]

Hoping this doesn't open a can of worms, but was thinking about this more today, since I want my tile hearth as close to 3/4" in height (future hardwood floor project in that room) and flush with the current carpet, is it okay to use 1/4" hardibacker board instead of 1/2" durarock? I think the 1/2" of durarock will bring it too high. I only need ember protection so I'm think this is okay with my Olso correct? Basically thinset, then 1/4" hardibacker, thinset, then 8mm tile.

 

[ccg36]

Material to be used for Type 1 ember protection is defined as anything "non combustable".

 

[Parallax]

I did this guy with slate over a 3/4 inch piece of furniture grade plywood. Clearly my foundation is combustible so I'll have to keep an eye on the grout to make sure it remains in good condition.

 

[FTG-05]

Check this link out. It has an R value chart.

https://www.hearth.com/econtent/index.php/articles/hearth_design

The chart is obsolete for Duroc NextGen, which is the only Duroc being sold now. It's R value, as stated above, is 0.39.

OP, be glad you only have to meet ember protection! My Englander 30-NC requires 1.5 R value! I had to use 4 sheets/thicknesses of Duroc NextGen to meet that requirement.

 

[firefighterjake]

Hoping this doesn't open a can of worms, but was thinking about this more today, since I want my tile hearth as close to 3/4" in height (future hardwood floor project in that room) and flush with the current carpet, is it okay to use 1/4" hardibacker board instead of 1/2" durarock? I think the 1/2" of durarock will bring it too high. I only need ember protection so I'm think this is okay with my Olso correct? Basically thinset, then 1/4" hardibacker, thinset, then 8mm tile.

Yes . . . just be sure that your hearth is rock solid with no flex.