Plywood floor getting soaked from rain.

[Codyboy]

My new 3/4" plywood floor has been soaked twice from rain. Looks like it will get a couple more soakings before I can get a roof over it.
How long can it last getting soaked , drying, more wet, more dry?

I have the walls and trusses up but trusses need more bracing and can't get metal on it until the weekend. It's supposed to rain for the next 2 or 3 days.

 

[larry_g]

Kinda depends on the ratings of the plywood. Some can go months, some delaminates when the dog pisses on it. What do you have?

lg
no neat sig line

 

[scottydosnntkno]

We build with truflor osb or advantech depending on the budget. My personal house sat exposed from nov-May the following year so 6 months with truflor osb. Most subfloor products are rated at least 180 days exposure. You’ll be fine as long as you let it dry out. Don’t cover it now , not heat the building and expect to install hardwood in April. It needs time to dry

 

[ducatithunder]

I built my garage and used Huber Advantech 1/2" for the sheathing and roofing. Cant say enough about it. It was exposed for a couple months in rain, didnt swell a bit. Great stuff and not really that much more then 7/16" CAT in my area. Huber has a 500 day exposure rating ... not saying Id do that but this stuff is pretty good.

 

[Codyboy]

It's called sturd I floor from mccoys
Features
APA certified
Great for single-layer floor construction
Touch sanded
Tongue and groove edges
32 Sq Ft/sheet
Exterior glue
Exposure 1
Not intended for prolonged exposure to weather
24" OC Span rating
Subfloor & underlayment
Allow 1/8" spacing at edge/end joints
Great beneath carpet & pad installations
Possesses high concentrated & impact load resistance.

I guess exterior glue is a plus but the not intended for prolonged exposure has me worried.

 

[Codyboy]

Boise cascade says rated for normal construction delays and weather.

So hopefully it will be fine.

 

[bczygan]

7 rains from mfg. to dried in.

That's the max we used to quote.

I wouldn't even like one.

Bill

 

[NUTTSGT]

Having a plywood floor, is this a shed or a full size garage. If it's small enough, you could possibly tarp it to keep a majority of the rain off of it.

 

[Codyboy]

Having a plywood floor, is this a shed or a full size garage. If it's small enough, you could possibly tarp it to keep a majority of the rain off of it.

16x20 shed. I bought a 20x30 tarp , but didn't have enough purlins up to support it before the rain. Going to try again today , not supposed to rain until tommorow.

 

[joey1320]

16x20 shed. I bought a 20x30 tarp , but didn't have enough purlins up to support it before the rain. Going to try again today , not supposed to rain until tommorow.

Can you lay down some 2x4 over the floor as spacers and throw the tarp over them so the rain doesn't get to the floor?

 

[ard]

It's a shed.

These 'floor plywood' are made to withstand this. I didn't like it, but it's fine

IMO you're over-worrying

 

[scottydosnntkno]

‘Prolonged exposure’ means like semi permanent. As it’ll don’t leave it exposed forever. At a very minimum a fooor sheeting product should be 180 days exposure

 

[Doozer75]

The attic floor in my garage I painted with Rustolium oil paint
before I put the roof on. The floor was 24x38'. I used a roller
and it took 3 or 4 gallons of paint. I chose silver and it looks nice.
It took a week or 2 to get the rafters up and the roof on, and then
tar paper. The floor might have gotten 4 or 5 rains, and it faired
fine. Floor was plywood. I have heard some home builders use
Thompson's water seal and mop it on. I figured oil paint was
better and it was not hard to roll it on.

--Doozer

 

[b-boy]

I built my garage and used Huber Advantech 1/2" for the sheathing and roofing. Cant say enough about it. It was exposed for a couple months in rain, didnt swell a bit. Great stuff and not really that much more then 7/16" CAT in my area. Huber has a 500 day exposure rating ... not saying Id do that but this stuff is pretty good.

I used the Advantech for a big project. That stuff is amazing. I purposely left a few pieces out over an entire Summer/Fall/Winter in Buffalo NY. No issues. No swelling.

 

[ItsNemo]

I wouldn't worry too much about a few soakings as long as it's plywood and not osb.

 

[hefnerconstructionlc]

You will be fine, they deal with that nearly every day in the Northwest.

 

[Codyboy]

Can you lay down some 2x4 over the floor as spacers and throw the tarp over them so the rain doesn't get to the floor?

Since the wall framing g is up its near impossible to cover it now except at the roof level.
No where for the plastic to hang over and it would just run in the sides and under.

As others have said, I'm probably over thinking it .

 

[Codyboy]

I wouldn't worry too much about a few soakings as long as it's plywood and not osb.

Yes plywood .

When we built our house the OSB got soaked for a couple weeks due to non stop rain and the roofers couldn't work.

It faired ok b7t did have some swelling around the edge. Still ticks me off that I didn't make tyem tear off the bad sheets and put down new.

 

[Norcal]

Some people paint the ply before framing to protect it.

 

[Davefr]

If exterior plywood couldn't withstand rain during the construction phase, there would be no homes. (at least in the PNW)

The key is to let the structure dry out thoroughly before doing any finish work once it's roofed/sealed.

 

[larry_g]

It's called sturd I floor from mccoys
Features
APA certified
Great for single-layer floor construction
Touch sanded
Tongue and groove edges
32 Sq Ft/sheet
Exterior glue
Exposure 1
Not intended for prolonged exposure to weather
24" OC Span rating
Subfloor & underlayment
Allow 1/8" spacing at edge/end joints
Great beneath carpet & pad installations
Possesses high concentrated & impact load resistance.

I guess exterior glue is a plus but the not intended for prolonged exposure has me worried.

read this; https://www.apawood.org/Data/Sites/1/documents/product-support/rated-sheathing-datasheet.pdf

And then look up other ratings on plywood.

lg
no neat sig line

 

[Radix2]

The worst thing is prolonged soaking if you have any standing water/ birdbaths/blocked areas from framing.

If you see it standing either commit to squeegeeing or drill a few holes to let it drain.

 

[Skiff Builder]

Cody,
Your fine. Pic below of my test board. Samples dunked and dried twice daily. Second one down from top is your shed floor. Its been through over 1000 cycles and still together.
Skiff