OSB? Am I crazy? - New Sugar House

[YoungFamilyFarm]

So. I ordered my new A&A 2x8 with a one piece hood going across the syrup pan from the raised flue (about 8" gap). There will be two separate steam stacks (divider between the pan sections) and we are going straight through the roof with peak jacks. I have no plans of a cupola with this set-up, but I do know that until the hoods and stacks are "warm" there will be some steam escaping the 8" syrup pan gap due to the lack of draft. I am building a 16x24 cook house with a 16x16 sap room which will be walled off so I don't have to listen to the pumps and R.O. 2x6 Rafter ceiling on 2' centers, 9/12 pitch. I am a big fan of metal roofing, but also want to 'sheet' with wood to avoid the major temp change and subsequent condensation that will occur on bare steel with whatever steam does escape the syrup hood. There will be a full length ridge vent, and I can always put a louvered fan vent on one end at the peak. My question is; 30 sheets of plywood is almost $1000 where 30 sheets of 5/8 OSB might be $250. I have seen people immediately highlight issues with glues and adhesives on engineered materials, but aside from that will the moisture exposure ruin the OSB even though it will be short periods of time and have time to breathe (dry out) in between? Or will I not have any issues at all with the hood set-up in place? What about general condensation in the building the other 10 months of the year from temperature fluctuations? I'm not opposed to using plywood, but if I don't have to spend the extra money then I will use it on one of the other 5000 things I need to purchase! Thank you everyone for your opinions and experience!

[mudr]

If you have a hood, I don't think you need any sheathing. Right?

[Maple Man 85]

I would think as long as you have your steam stacks high enough to get a good draft there shouldn't be an issue. I would still expect to see some but I don't think it would be enough to ruin the OSB. It is not for a structural integrity so you should be fine.

My question if you are building a new sugar house why would you want to cut corners? Spend the extra money and you'll be happier in the long run. If your arch is insulated properly there shouldn't be that much heat transfer so it shouldn't sweat. I had the chance to experience what a properly insulated arch was like and it couldn't even keep the building warm.

[unc23win]

I agree with Maple Man not knowing exactly what arch you have I don't think you will see much sweating if any at all and I wouldn't expect much heat from it if its well insulated. Some steam will go out and around just like you said off the front but I doubt it will be enough to have any issue. It might depend on ceiling height, but sounds like you have plenty of height.

I have an oil fired arch and it gives off almost no heat the only place it is warm is with 5 feet of the 15" exhaust pipe I have a steam hood and 1 17" steam stack no ceiling yet and no heat from the evaporator. I plan on doing a ceiling this summer most likely white steel and some sort of heat.

[n8hutch]

Probably don't have any pine Mills in P.A.?

Around here you can usually find 1000 board ft bundles for 350-400. To Tounge & Groove. Makes for a real nice look.

But I agree that the OSB should be fine.

[Pibster]

My sugar shack is 4 years old and the OSB roof sheathing looks like the day I put it in. I always planned to sheath the inside of the building with boards but never got around to it. The OSB is working fine.

[johnallin]

When I built my sugar house I used 2x10's for sheeting under the metal roofing. They went up very quickly, look great,are strong and insulate better than single plywood.

Call a local lumber yard, where the builders go - not a big box lumber yard. Ask for pricing on a bunk of 2x10's 24' long. You may be pleasantly surprised.

[YoungFamilyFarm]

Probably don't have any pine Mills in P.A.?

Around here you can usually find 1000 board ft bundles for 350-400. To Tounge & Groove. Makes for a real nice look.

But I agree that the OSB should be fine.

It's all rough cut hemlock down here for 'local' lumber. Everyone uses it for batten style siding, but then the knots fall out and snow comes in :) I wish we had pine mills in our area, especially when I see these nice sugar houses the New Englanders have!

[YoungFamilyFarm]

When I built my sugar house I used 2x10's for sheeting under the metal roofing. They went up very quickly, look great,are strong and insulate better than single plywood.

Call a local lumber yard, where the builders go - not a big box lumber yard. Ask for pricing on a bunk of 2x10's 24' long. You may be pleasantly surprised.

Great Tip! I'll give em a call!

[Michael Greer]

One of my builder friends calls that stuff "smorgasbord for mold". I used planed white pine and I really love it. No matter what it will get steamy and wet in there when you cook. Having doors and windows that can easily open helps a lot.

[Ghs57]

I used white pine also. I have found that no one comments on how nice your OSB looks when they visit.

[WESTVIRGINIAMAPLER]

My sugarhouse is 12 years old and has many many days of steam and OSB looks as goog as it did 12 years ago.

[Big_Eddy]

My 2011 OSB roof deck is not looking good. It will need replacing long before I was hoping for.

[johnallin]

It's hard to bet 2x8's or 2x10's for roof sheeting.

[seandicare]

if you are set on the OSB, maybe you could coat the underside with an exterior paint?

a buddy of mine has a huge evap with hoods, his barn is metal roofing and siding with no underdeck other than lathes to hold the metal sheets up. I did not see any condensation issues even on colder days

[YoungFamilyFarm]

It's hard to bet 2x8's or 2x10's for roof sheeting.

That looks awesome. Wow! Nice job!