steel studs for hearth

[greythorn3]

do you guys think its ok to use galvanized steel studs for the hearth? my nc30 is in and i need to build a hearth theres a guy selling galvanized steel studs 2x8's by as long as i like for 1$ a linear foot

would these be ok to use?

 

[fsr4538]

That is exactly what I used. They are non combustible, and you can use them just like wood framing. If you are concerned about heat conduction to combustible walls etc, use ceramic electric fence insulators as spacers between stud and wall. For the floor you will build the proper r value between stove and studs with hearth materials (Cement board, stone, tile etc.)

Hope this helps.

Forrest

 

[Wood Heat Stoves]

Steel studs would work great and be safer than wood studs if anything. Just be sure to follow all the manufacturers specs for the hearth size and construction, especially surface material.

 

[Dakotas Dad]

They come in different gauges, you want 18 gauge, not 22 or 25, which is what most steel studs are... They work fine for hearth building, I back probed my framing last winter with a thermometer, the studs surfaces away from the stove were at ambient, with the stove having been run pretty hard for several days when I checked them.

 

[pen]

Here's a question, if he were to use steel studs and insulate w/ fiberglass bats between them, could he simply put down 3/4 in of concrete backer right to the studs then tile on top of that since his combustible is the floor instead of the studs or a plywood underlayment?

pen

 

[begreen]

I would modify things a bit for greater rigidity. First I would skin the top of the steel studs with sheet metal pop riveted every 8" or so. Then I would use a double layer of cement board, screwed through to the studs. The second layer of cement board should be laid at a right angle to the first layer to avoid seam alignment.

 

[Highbeam]

Here's a question, if he were to use steel studs and insulate w/ fiberglass bats between them, could he simply put down 3/4 in of concrete backer right to the studs then tile on top of that since his combustible is the floor instead of the studs or a plywood underlayment?

pen

That's what I did to meet the high required R-value for my Hearthstone hearth. From the plywood subfloor, 2x4 steel studs (galvanized of course), then two layers of 1/2" durock for rigidity, then tile. I didn't fill in between the studs with anything since the air gap provided sufficient insulation.

 

[Dakotas Dad]

Here's a question, if he were to use steel studs and insulate w/ fiberglass bats between them, could he simply put down 3/4 in of concrete backer right to the studs then tile on top of that since his combustible is the floor instead of the studs or a plywood underlayment?

pen

Yes, see the link in my sigline..

 

[greythorn3]

well they are 16 gauge the ones

my concern was the galvanizing, do you think its ok to use indoors? i dont want to cause toxic gas in the house

they are also 2 x 8" so thats allot of airspace between the top and the floor.. i was thinking cement board the top with 2 layers and then the bottom with 1 layer, and all around the sides, then tile it with tiles also.

 

[Fsappo]

Not for nuthin, but Steel Stud was my nickname in prison.

 

[begreen]

well they are 16 gauge the ones

my concern was the galvanizing, do you think its ok to use indoors? i dont want to cause toxic gas in the house

they are also 2 x 8" so thats allot of airspace between the top and the floor.. i was thinking cement board the top with 2 layers and then the bottom with 1 layer, and all around the sides, then tile it with tiles also.

Not an issue. It takes high heat to get the zinc plating to outgas. Galvanized sheetmetal is used all the time for ductwork in houses without issue. No need to put the additional layer of cement board on the bottom.

 

[Highbeam]

Even welding zinc plated (galvanized) steel is not as hazardous as many folks think. Don't sit there and inhale the fumes right from the weld but it's not poison. Yes, zinc is toxic, yes, water is toxic too if you expose yourself to too much. Both are also vital to survival.

What I am saying is that galvanized steel in your hearth is totally safe.

 

[greythorn3]

well heck i got around to picking up my cement durock board in 1/2" so you guys are using 2 layers and are you thinset motor them together? or with steel studs should i even worry about the thinset?

last time i built a hearth it was wood studs with cement wonderboard 2 layers thinset motor together..

gotta put the steel frame togeather still, will try to get some pics this weekend.. 4 u guys

Oh by the way the morons at homedepot accidently put my stove on the floor and it sold, so they had to order me a new one.. so it will be in 4 - 6 weeks from last week!

oh well winter a long way off still and i dont got any of the chimney stuff yet.

 

[Wade A.]

Greythorn....put me down as +1 for doubling up on the backer board, not just for added R value, but for rigidity, i.e. less defelection. Thinset between the layers too. Nothing would be more depressing than to lower your stove down on the hearth and see your grout lines crack. or possibly even your tile or stone itself.

 

[begreen]

+2 Punching a hole through the hearth as you are standing on it with a 500 lb. stove might be a bit more depressing.

 

[Wade A.]

Oh yeah, umm, that too!

 

[Highbeam]

I for sure recommend thinset between the layers. What you are doing is creating a laminate product that is one inch thick. Ever notice that when you buy plywood there are several layers of thin veneer glued together? That allows the sum of the layers to act as one big layer. Sometimes even stronger than a single thick layer.

I put on the first layer of durock and screwed it to the steel studs. Walked on it of course and it was spongy and squeaky. The second layer was glued and screwed to the first and the system then became rigid.

When laying out your steel studs be sure to place support directly under the stove feet. Most of your hearth weight is point loads on those stove feet.

 

[rottiman]

Not for nuthin, but Steel Stud was my nickname in prison.

Coulda been worse if they had nicknamed you "Iron Donut".....LOL

 

[greythorn3]

well heck thanks guys.

I dont know about where the feet will be since i dont have the nc30 onhand right now. im gonna use the legs instead of the pedistal though. i think i could just laydown a steel plate or plates under each foot ontop the tile afterwards maybe

 

[begreen]

If this is a concern, you can pop rivet a skin of regular 26ga sheet metal to the studs under the cement board. That will really stiffen up the support.

 

[greythorn3]

heck i could turn some studs on their flats to go across in the stove aproximate area too that would work! they are thick! good idea..

 

[Dakotas Dad]

I did my studs 12" on center, and that put one very close to directly under every leg. I did double up the wonderboard, and used thinset between the layers.

 

[greythorn3]

ok heres what i got so far, gonna go out to the barn later and see if i can find me some sheel metal to go over the top some before i put on the cement board

 

[begreen]

If you can't find any sheet metal, consider putting a stiffening brace set across the center of all the ribs.

 

[greythorn3]

had some scrap stud left so took your advice and notched it and dropped it in, will get the sheet metal in a while to put in around it