winterize foundation/subfloor for a few months

[azkateo]

Hello to all,
FINALLY getting to put in my foundation for my little cabin (144sf) - Hooray!  I will be putting in 6 post/pier and then the 3/4" T&G subfloor.  I won't be able to do the walls or roof 'til spring - can I just staple on a huge tarpaulin over it all or will that create moisture problems with the T&G?  BTW, the cabin is going to be in range country of northern AZ - so cold, up to 8" of snow, lots of wind and of course sunshine.
Thanks for ideas!
azkateo

[John Raabe]

I think I would get the tarp to drain by building up a ridge (vertical 2x10?) at the centerline and tacking some flat 2x4s down to the sides. Then cover and nail the trap down through lath strips on 4 sides leaving a fold of the tarp for a bit of ventilation at each gable end.

Others may have better real world experience.

[Redoverfarm]

For no more than a few dollars I would invest in Advantech subfloor.  Tarps have a habit of breaking down .  I would say with buying a good heavy duty tarp you would be in the range of using Advantech and not have to worry. 

http://huberwood.com/main.aspx?pagename=advantechflooring

[MountainDon]

Unfortunately here in the west Huber does not seem to have any product retailers.   At least that's what I found when I was considering my options.

Tarps and plastic all seem to develop small leaks on their own in my past experience. Hpwever if you can create a ridge and maintain that sloped tent like shape you will be much better off than having the tarps flat on the deck. I found small pinhole type leaks let liquid water through but then the water was trapped underneath.   Keep in mind that winds can cause havoc with flapping and causing stress tears.

One of our members, I forget who, but somewhere in the east I think, tarped over a floor. In spring he ended up replacing all/most ? of the subfloor because of water damage.

[rocking23nf]

I didnt tarp my subfloor last winter, and im in northern alberta.  It held up just fine.

[MountainDon]

OSB or plywood?

[rick91351]

I didnt tarp my subfloor last winter, and im in northern alberta.  It held up just fine.

I think one reason it worked well in northern Alberta is everything is to frozen to do any damage.  Then the gentle clippers, or breezes, made that - winds.  They make sure nothing settles on anything flat.    

[MountainDon]

When we built our cabin our timing was bad, or perfect, as monsoon season started the day the OSB subfloor went down and continued until the roof was papered. It didn't rain every day, it just seemed like it. I was there most of the time so was able to sweep the water off the surface. It was warm and sunny enough between rains to allow the floor to dry. There ended up being several spots where the OSB flaked off pieces. I was wishing I'd used genuine exterior grade plywood or Advantech (not available in my area though). In the end it turned out okay as it was all covered in Hardi fiber cement panel underlay to be tiled.

I really think it would have turned out much worse if it had been left alone with puddles here and there or if it had been covered and left. We did try covering the floor and the brand new material had pinhole leaks that water found.

The experience may vary. I also think the freezing weather may be a help. If the winds blow the snow off during the winter, then come spring there might not have been all that much water sitting in puddles.     

[rocking23nf]

we used a PT plywood. since it was close to the ground.

[TheWire]

My cabin floor sat out over a winter in Wisconsin.  However, all the floor framing and the deck were pressure treated.
http://countryplans.com/smf/index.php?topic=4640.0

With your small area, 5 sheets of plywood should cover it and pressure treated 3/4" is about $15-$20 more per sheet than OSB.

[JRR]

I have suggested, but never tried myself, using decking for the subfloor system.  It should weather pretty well if the conventional decking spacing is used.  The diaphragm effect of decking should be pretty good, perhaps not quite as good as plywood decking (but perhaps better than damaged plywood).  You could then finish out the wall framing, bottom wall plates directly ontop of the decking ... and then constuct roof structure ... next, sheath the walls ... then come back and add a plywood flooring atop the decking.  Perhaps other than plywood, other flooring materials such as tile, could go down against the decking.  Foam insulation could be sandwiched in if desired.

May be cost prohibited.  Of course, wall framing heights may have to be adjusted slightly.

Just thinking aloud.

[MountainDon]

Son of a gun. I was in my Lowe's this afternoon and they had Advantech subflooring!! 

[Redoverfarm]

Son of a gun. I was in my Lowe's this afternoon and they had Advantech subflooring!!  

I guess they realized that there was a demand for the product Don.

azkateo  If you have made a decision about roofing material there is an easy fix for your delimia if you chose a metal roof.  Go ahead and buy the necessary panels for the roof and use those to cover your subfloor.  The sf is not that large and by laying a couple 2X4 in the center that would be enough pitch to each side if you would lay the metal panels on the subfloor just as you would laping on the roof.  Just make sure that you lay a little weight on top 9Extra 2X material to keep the wind from lifting them up.