13nc hearth

[Rebelduckman]

I'm setting here thinking of how to go about this 2.0 r hearth. I think I want the top layer to be brick or pavers. What would you go with underneath? I have a couple sheets of 3/4 plywood and some 1\2 durock already that I've had for awhile. This is a corner hearth. Tia

 

[Jags]

Keep in mind that you can't count the plywood as any R factor as it is combustible. You are gonna need R2 in between stove and plywood.

 

[Rebelduckman]

Keep in mind that you can't count the plywood as any R factor as it is combustible. You are gonna need R2 in between stove and plywood.

Gotcha

 

[Rebelduckman]

I'm gonna raise the hearth quite a bit. My knees aren't the best.

 

[swenny]

rebel i did a corner hearth for my 13- i did the perimeter with 2x4's ripped down to 2.5 " screwed it all together than used used 2 1/2" durock piers every 8 inches for support in the middle than 2 sheets of durock on top than ceramic. think the rvalue is like 2.4. when the stoves runnin bout 600degrees the ceramic tiles are barely warm, if it wasn't for the insurance co.i would've just used pavers.....have fun

 

[Rebelduckman]

rebel i did a corner hearth for my 13- i did the perimeter with 2x4's ripped down to 2.5 " screwed it all together than used used 2 1/2" durock piers every 8 inches for support in the middle than 2 sheets of durock on top than ceramic. think the rvalue is like 2.4. when the stoves runnin bout 600degrees the ceramic tiles are barely warm, if it wasn't for the insurance co.i would've just used pavers.....have fun

Pretty good idea. How wide were the piers?

 

[Rebelduckman]

2 .5" pieces up on their edge?

 

[swenny]

no, i cut 3ft strips of drock 3.5" wide then stacked them on top of each other than ran acouple 3.5" screws on each end to hold it together...

 

[begreen]

One could use heavy gauge metal studs instead to eliminate the need for the piers. I would probably skin the top before the durock with sheet metal pop riveted to the studs to provide a stiffer backing for the durock.

 

[Jags]

Or for the minimal costs and quantity of the studs you could go to half spacing at 8" on centers.

 

[Rebelduckman]

One could use heavy gauge metal studs instead to eliminate the need for the piers. I would probably skin the top before the durock with sheet metal pop riveted to the studs to provide a stiffer backing for the durock.

Where would one find the heavy duty ones?

 

[Jags]

20ga and 25ga is common in the big box stores but that is fairly light gauge. Any drywall supply store that deals with commercial building supplies will have what you need. Depending on your build, they should also carry 6" to 12" wide studs. Be AWARE - steed studs are NOT designed to be laid on their sides. The get their strength from being vertical.

 

[Jags]

How tall do you plan on making the hearth pad? You may want to alter your design and build the "rise" with mini knee walls (of steel). If you have a steel cutoff saw, this would be quite easy to do.

 

[begreen]

Just to clarify, do you mean they are stronger on edge than laid flat face down?

 

[Jags]

No-no. On edge is their weakest position. That is why I am recommending vertical (stood upright) as their strongest potential.

 

[begreen]

How much is this a factor with 20 ga studs on edge, 12" apart? It would seem that even with a load of say 700# (stove and 2 layers cement board) spread over a 36 x 48" hearth is only going to come to about 2.5# per sq in.. The reason I ask is that we have seen several hearths made this way. I haven't heard of any failures or problems.

 

[Jags]

20ga is far better than 25 for this application, but I personally would look at 18ga. I can wrap my hand around a 25ga stud and crush it like a beer can.

Full disclosure: I build things like I expect an errant dump truck to fall out of the sky at any moment.

 

[Rebelduckman]

How tall do you plan on making the hearth pad? You may want to alter your design and build the "rise" with mini knee walls (of steel). If you have a steel cutoff saw, this would be quite easy to do.

6-8 inches or so

 

[Rebelduckman]

I figure with 2x4 studs, 2 layers of 1\2 durock and tile it'll be around 5 inches or so. Depending on the choice of tile. Would pavers work instead of tile?

 

[begreen]

Either will work, but 2 layers of durock nexgen is only R=.78. Or are you now thinking metal studs? What will back the cement board?

 

[Jags]

Remember - you are aiming for R factor. I am not sure what the R factor is for the air gap (2x4 studs if using metal), but make sure you have it calculated out correctly.

 

[Rebelduckman]

Either will work, but 2 layers of durock nexgen is only R=.78. Or are you now thinking metal studs? What will back the cement board?

Yes if I can find the heavier ones. It'll be a 2 someway, somehow regardless. I even got the heat shields for sides and plan to do a wall shield. Don't want to have to worry

 

[Rebelduckman]

Remember - you are aiming for R factor. I am not sure what the R factor is for the air gap (2x4 studs if using metal), but make sure you have it calculated out correctly.

I saw on a table 1-4" air gap is 1.0 R

 

[Rebelduckman]

I feel like a kid before Christmas lol. The 13 is in Atlanta headed to Richland Ms. Be here tomorrow!

 

[Seasoned Oak]

I'm gonna raise the hearth quite a bit. My knees aren't the best.

Raised mine 16" for 3 of my stoves. 2 nc-30s and a country hearth 2000. Only the harman is already fairly tall and dont need the lift.
Those darn 30s are so short, got to lay on the floor to see the fire