Blaze King Ashford hearth

[drz1050]

Building a hearth for the Ashford that should be getting installed in the next few weeks.. going to do a bluestone, but want to make it level-ish with the floor. Cutting the floor out down to the subfloor now, was going to lay a piece of sheet steel under in case any embers fall through, then bluestone on top.

For the plate steel ember protection- what's the minimum thickness? I was originally going to go with 11 ga, but the guy at the fabrication shop around the corner from me thinks 14 would still be more than enough, and save me a few bucks.

Hearth size will be 52x42.

Thoughts?

 

[webby3650]

24 gauge is the minimum thickness. With no subfloor, sounds like you will need some thick metal for support. But the blue stone also qualifies as ember protection. No metal is necessary.

 

[drz1050]

Not cutting the subfloor out, cutting out the hardwood that's on top of the subfloor. Putting the metal down on the subfloor, then the stone on top of that.

Thanks!

 

[webby3650]

Not cutting the subfloor out, cutting out the hardwood that's on top of the subfloor. Putting the metal down on the subfloor, then the stone on top of that.

Thanks!

Ahh, ok. Assuming the stones will be mortared down and mortared together I'd skip the metal. Not sure how you would bond the stone to the metal anyway?

 

[drz1050]

Was putting the metal down just in case any embers fall through the cracks between the stones.. yes they're going to be mortared, but I'm not the best mason, and I'd like for it to be forever proof.

Was originally going to put a concrete board down, then build up on there, but I want the hearth to sit close to level with the floor now, so don't really have room for the concrete.

 

[Highbeam]

Was putting the metal down just in case any embers fall through the cracks between the stones.. yes they're going to be mortared, but I'm not the best mason, and I'd like for it to be forever proof.

Was originally going to put a concrete board down, then build up on there, but I want the hearth to sit close to level with the floor now, so don't really have room for the concrete.

Metal is unnecessary with grouted stones so any thickness of metal will due. 24 gauge should be reasonably cheap and easy to work with. The metal layer provides the benefit of easy demolition since you will likely just nail it to the subfloor. It's a pita when somebody mortars something right to the subfloor.

 

[webby3650]

How do you plan to bond the stones to the metal?

 

[drz1050]

How do you plan to bond the stones to the metal?

Was just going to mortar them down... would the expansion/ contraction of the metal at temp crack the mortar? I wouldn't think much heat would make it through the stones...

 

[webby3650]

The mortar will not bond to metal. You'll have a big floating hearth, then 1 by 1 the stones will seperate from each other as everything moves. It only has to move a fraction of inch to break bond.

 

[drz1050]

Ugh.. that doesn't sound fun at all. So is the only way to have a floor level hearth to forget about the metal?

What about liquid nail? Seems like that stuff will hold anything.. liquid nail them down, then mortar between?

 

[webby3650]

I would use 1/4" cement board and mortar it down. It's not generally recommended to use glue.

 

[webby3650]

If you want it to be flush tile is the way to go. Have you looked for a cerimac tile that looks like the stone you have picked out?

 

[drz1050]

Was kinda thinking tile, but like the look of irregular stone so much better. I can get bluestone at ~5/8" thickness, maybe some pieces 1/2

 

[therdlesstravld]

Use an uncoupling membrane like kerdi. Durock also makes its own roll out underlayment as does mapei. I just used the mapei for a shower niche and was able to buy it by the foot at my local tile distributor. You would mortar the uncoupler down and let it set and then mortar the stone directly to it. This stuff is less than a 1/16" thick it wouldn't bring you up any noticeable amount. Use a v-grooved trowel for setting the membrane as you'll get a small ridge.

Don't worry about ember protection under your bluestone. You'd have to be slightly retarded (I have faith in you!) to not be able to grout the lines. Show some pics when your done it sounds like it'll be great.

 

[webby3650]

I haven't seen any info that says this type of underlayment is approved for exposure to heat. Might be ok?

 

[begreen]

I'm with webby, put down 1/4" cement board for a good bond and better thermal break. I would not put glue or plastic membrane under a hearth.

 

[therdlesstravld]

Good point, give Ditra a call and see what temperature their membrane can withstand. Id wager there's a fire retardant membrane by some manufacturer.

 

[Shane Collins]

I made my hearth for my BK Ashford last year and did way too much research and worried about it too much. I also wanted it level with our floor. I put down a sheet of 1/4 inch durock on top of the subfloor and tiled on top of that. I used a ceramic tile that mimics bluestone. As far as I'm aware Ceramic tile is typically much stronger and more durable than natural stone. I did want natural stone but even more than that I wanted something I wouldn't have to worry about replacing. Your embers will not get through your grout and even if they somehow managed it they'd still have to get through 1/4 inch of durock before getting to the subfloor. Don't waste your time with putting down any sheet metal. As others have said the tile will not adhere and you will create much bigger problems. Stick and screw the durock to the subfloor then tile on the durock and you're good to go. Mine has been down for over a year now and looks like new.

 

[drz1050]

Thanks everyone! Think I'll do the 1/4" board then..

Shane, can you post a picture of your setup?

 

[Shane Collins]

Thanks everyone! Think I'll do the 1/4" board then..

Shane, can you post a picture of your setup?

Sure, here it is. I currently have carpet. Once the kids get older I'm going to replace it with wood flooring, but for now carpet is safer for the young ones! I planned it so I could install 3/4 inch hardwood floor and it would be flush to the tile. 3/8 inch tile 1/8 inch of adhesive and 1/4inch durock just about does it. There may be a slight bump but there are ways around it. I know some wood flooring is less than 3/4 inches thick so you may have to do something to make it flush but it's definitely doable. Good luck!

 

[drz1050]

Thanks, that looks great!

My design is going to be very similar, but a mirror image.. the extended portion is going off to the left instead of the right, and there's no wall on the other side. Still undecided about putting a rock veneer on the wall behind it.

 

[Shane Collins]

Thanks, that looks great!

My design is going to be very similar, but a mirror image.. the extended portion is going off to the left instead of the right, and there's no wall on the other side. Still undecided about putting a rock veneer on the wall behind it.

I thought about putting some kind of rock veneer/tile on the wall too. It would only change the aesthetics and be a fair amount of work/money so I decided there was no point. I would have liked to have it kitty-cornered but the pipe would have hit a joist or the stove would have stuck out into the room too much to do that. It worked out well in the end. It's a fantastic stove. Heats our 2500 square feet house by itself with no problem. (properly seasoned wood required though.)

Good luck with your install and hearth, put some pictures up when you get done.