sugar house roof sheathing

[Tapped Out]

Wondering what people use for roof sheathing on their sugar houses. We are planning on a metal roof, but want to use some type of sheathing below the metal so the moisture doesn't condense on us. OSB would probably delaminate, but wondering if plywood is not a good choice either? :confused:

[Thompson's Tree Farm]

I used one inch pine and hemlock but I have my own timber and sawmill. Not sure how it would stack up cost wise compared to plywood.

[Timberwolf]

I have seen similar threads on here before and some have put insulation on the underside of steel roofing. Depending on the cost insulation would be a great option.

[twitch]

I used 1" pine boards

[gmcooper]

5/8" CDX plywood is what we use in our construction business. You should put a moisture barrier under the metal roofing to prevent condesation from dripping off the metal roofing and leaking thru the cracks between the boards or plywood. 15 lb roofing felt (tar paper) works for that.

[heus]

Like gmcooper my metal roof is over top of cdx plywood with roofing felt in between.

[maple flats]

My roof is steel over 1x10 hemlock, spaced 6". It rained before I built a hood. I now get no rain.
That being said, don't do it my way. Use either plywood or any lumber, with no spaces and use 15 or better 30# felt between. I wish I had, but not likely to change any time soon.

[Tapped Out]

Thanks for your input.

[maple flats]

Let me clarify my post. Build the deck, plywood or unspaced lumber, then use 15 or 30# felt, then install the steel roofing.

[heus]

Yep, thats what I meant, too.

[northwoods_forestry]

When I built our sugarhouse a couple of years ago, I was advised not to use felt or tar paper between the 1" pine sheathing I used on the deck and the metal roofing (or to use anything above the pans that contains potentially harmful substances including OSB or plywood). The issue being toxic condensation making its way into the pans. I can't say for sure that this is a legitimate concern, but I can say that I haven't had any condensation problems having not used paper between the deck and the roofing.

[maple flats]

You know what, that sounds like a good idea, one I had not thought of. No felt/tar paper!

[WoodButcher]

i put 5/8" plywood down(21/32" at home depot?) and put 30lb felt on top overlapped 6-10" on felt layers.
i didnt choose cdx for several reason , the main one being research on this site. cdx is great.. if it isnt by moisture. it likes to pull and twist. 21/32" or 5/8" or whatever plywood the big box store has is what i got. its only 5$ more per sheet and gives the metal roofing screws a better bite.

plus i have been in couple sugar houses without sheathing and just strapping to attach the metal roofing , and theres only a few places inside the shacks where you wont get rained on.