What Is The Right Way To Build A Heat Shield With Durock

[CWYfire]

What is the best way to build the 1" air space behind Durock for a heat shield? Is there a specific manner it is to be built to comply with code?

I was thinking what would be the easiest is ripping strips of Durock (about 2-3" wide) or even cutting those strips into shorter blocks so that air can also move across ways behind the shield, screwing two thicknesses of 1/2" Durock strips to the studs to create the 1" void. Then either screw the larger (3'x5') sheets of Durock to those strips or even all the way through into the wood studs.

My questions:

1. Should I use 1 1/4" Durock screws attaching the Durock sheets only into the strips?

2. Or should I get longer screws (say 2" so at least 1/2" penetrate the studs) and attach the sheets through the strips and into the studs?

3. I was concerned that the longer screws would be a heat conductor directly into the combustible wood studs.

4. I was also unsure if the shorter ones would hold the weight of the sheets that will also have tile if they are only attached to the Durock strips?

I messed around and forgot to post this till the last minute.... I hope some of you Wood Stove Wizards get a chance to respond as it is getting late here. Any and all expertise or guidance on these issues would be appreciated as I am hoping to get the chimney pipe in and build my heat shields tomorrow, (on Sunday).

Thanks
Ed

 

[thebeatlesrgood]

well, you're going to be laying durock and tiling the wall so grab a nail and a hammer and find those studs they measure 16 inches on center so you could find one then go from there but i would just check every one as you probably arent doing a big area. forget about the metal conductor into the stud, you NEED to hit studs. i dont know how close the stove will be able to get but even at lets say 12 inches, without any heat shield you'd still probably be ok (no fires) for months if not years but at a certain point the studs could pose a risk. but, you will have a heat sheild so everything should stay a hell of a lot cooler with no worry about the metal conducting heat to the stud. the fact of the matter is those sheets of durock are heavy, the mortar (cement) is heavy, tile is heavy. after its all said and done (depending on the area of the heat sheild, you could have close to 500 or more pounds. you should lay the strips on the studs, tack them with nails (roofing nails work well with the big flat heads) then screw the 5x3 sheets through the strips and studs.

hope this helps

 

[thebeatlesrgood]

oh btw. cutting them into shorter strips seems to be a good idea, just make sure when you screw through the 5x3 sheet you're hitting the strips.

good luck

 

[thebeatlesrgood]

this is the last time i promise :red: (sry im tired and i can't fall asleep). make sure you leave a space on the the top and bottom so that air is able to pass through. im sure you already knew that but just in case.