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Greg_in_ri (Greg_in_ri)
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Username: Greg_in_ri

Post Number: 4
Registered: 06-2012
Posted on Wednesday, July 04, 2012 - 09:38 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks for the link. I will read through. I'd like to stay away from any combustibles. I do have 4" of refractory insulation over the dome and generous air space between that and the roof. I've thought of gable end vents to help the cavity breathe and if I do that I may consider the wooden lathe. I like the wiring idea for its simplicity but right now I feel I'm still gathering information. I probably have a month before I really need to decide but I do have the slate. Got 300 nice reclaimed pieces for $1.50 each.
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Old_school (Old_school)
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Username: Old_school

Post Number: 844
Registered: 01-2009
Posted on Monday, July 02, 2012 - 09:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Joe, I don't think he wanted to use any wood because of the heat and fire. I like your ideas if he will use the wood!
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Joe (Joe)
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Username: Joe

Post Number: 692
Registered: 07-2006
Posted on Monday, July 02, 2012 - 11:15 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Put your cement board down and attach horizontal wood nailers over it, min. 3/4" thick. Nail, don't screw, the slate to the nailers. Read the SRCA slate roof installation guidelines: http://slateroofers.org/downloads/SRCA_Installation_Guidelines_V2.pdf
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Old_school (Old_school)
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Username: Old_school

Post Number: 841
Registered: 01-2009
Posted on Sunday, July 01, 2012 - 06:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Sure, you normally have two holes in the slate and you can either wire one wire through both holes or two wires in each hole. It will work just fine. Try and couple and see what you think. You could do the same with the ridges or perhaps you could use a metal ridge piece. If you are worried about bugs and such at the lap joints of the slate, you could always get a bit of Flexim and seal them right up. As long as it is beneath the overhang and doesn't get direct sun it would be fine. It would also tighten them up a bit. Try it!
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Greg_in_ri (Greg_in_ri)
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Username: Greg_in_ri

Post Number: 3
Registered: 06-2012
Posted on Sunday, July 01, 2012 - 01:46 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks for the suggestion. Interesting thought.

Will the wires keep the slate from moving in the wind? Also, what about the ridge? I guess I could screw the flashing and shingles to my ridge beam. Another consideration would be sealing the oven cavity along the edges from flying bugs and other vermin if I don't use an underlayment. Maybe a trim board could serve this purpose.

Have you wired shingles in the past?

Thanks,

Greg
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Old_school (Old_school)
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Username: Old_school

Post Number: 836
Registered: 01-2009
Posted on Wednesday, June 27, 2012 - 07:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

If that is what you are trying to accomplish, just screw some hat channel down to the rafters and wire the slates to it. No underlayment and not fire hazard. Cement board is not a fastening surface and it would break too.
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Greg_in_ri (Greg_in_ri)
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Username: Greg_in_ri

Post Number: 2
Registered: 06-2012
Posted on Tuesday, June 26, 2012 - 07:55 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hey, thanks for the quick reply.

Attached is a picture of an oven under construction (not mine but pretty close). I am putting the cement board over the metal rafters and then attaching the slate shingles to the cement board with screws. The screws are 0.20" diameter. From your post I get the sense I could attach some light weight firring (like corner bead for wall board folded over) lengthwise across the rafters and screw shingles to that? I want to use non-combustible materials throughout.

Thanks,

Greg
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Old_school (Old_school)
Senior Member
Username: Old_school

Post Number: 835
Registered: 01-2009
Posted on Tuesday, June 26, 2012 - 06:50 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Maybe I am missing something here, but are you talking about a nailing surface to support the slate, or an underlayment beneath the slate. The slate really doesn't need an underlayment, but it must be supported. Slate will not burn and it needs no fireproofing. The wooden deck beneath it may need to be protected from the heat, but you could always just install some slate on the ceiling surface and it would do the same thing. Not sure of the question.
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Greg_in_ri (Greg_in_ri)
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Username: Greg_in_ri

Post Number: 1
Registered: 06-2012
Posted on Tuesday, June 26, 2012 - 02:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I'm building a wood fired oven and would like to use slate for the exterior roof as I have found an excellent source for the small quantity (100 square feet) I need. My question is whether anyone has ever used something like Hardy Backerboard as an underlayment? The underlayment will be exposed to a fair amount of heat even with my fire dome insulated, so I want to use something fire proof. I would use the "magic screws" recommended for Hardy board but I'm not sure what other details I might need to be aware of when installing slate over cement board. Any other recommendations to this approach? I have been educating myself on the basics of installation like ridge, drip edge, hip, etc.

Thanks. Greg

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