# 3/4" osb or 3/4" plywood for new sub floor?



## treerat (Feb 13, 2011)

what are the pros and cons of 3/4 " osb vs plywood for new sub floor?

and if I go osb how long can it be exposed to the weather while I get the walls up and roof, can it get rained on or will that ruin it?


----------



## Just Bill (Dec 21, 2008)

I am old school so my view are different from younger guys. I prefer plywood. It can get damp(neither likes WET/soaked) longer than OSB, and IMHO is stronger. Plywood is more expensive. Both are OK with most building codes, OSB is the construction preference because of cost.


----------



## bernieb (Mar 20, 2010)

Everything depends on the weather, how complex and time consuming the house is, and quality of help you have, and how soon you can get it under roof. OSB or plywood are good products, but I'd go with plywood if you have a crawl space over dirt, with moisture conditions, and use glue , squeaks are hell.


----------



## gotogregg (Sep 16, 2010)

Hey Treerat,

I have experience with how OSB and plywood will react over time outdoors. OSB will eventually get ruined. It absorbs water, swells up, and start to crumble into pieces. Regular plywood is a little bit better. It doesn't absorb as much water, it will still swell, and it will warp, but wont fall apart as easily. I would definitely go with regular 3/4" plywood. What are you doing exactly?-Gregg


----------



## tcleve4911 (Nov 6, 2010)

Neither one of those are a good choice at all because you stated that moisture and rain will be a factor.

Advantech ....period!!!!!


----------



## DexterII (Jul 14, 2010)

Yup, Advantech.


----------



## kwikfishron (Mar 11, 2010)

Whichever you choose don’t build your floor and then the walls in a couple of months and the roof months after that. I’d get everything together and not start until you can at least get it all dried in.


----------



## treerat (Feb 13, 2011)

this is a bathroom REBUILD! foundation up, one person show. probabably take me about 3 weeks, but its spring and I can expect rain every other day, just wanted to know if osb would survive that amount of time and getting soaked every few days? would a tarp help much?


----------



## kwikfishron (Mar 11, 2010)

You should be fine, just make sure you have a sufficient tarp to cover it all and focus on the roof and siding before messing with the inside.


----------



## JCarsten (Jul 6, 2010)

treerat said:


> this is a bathroom REBUILD! foundation up, one person show. probabably take me about 3 weeks, but its spring and I can expect rain every other day, just wanted to know if osb would survive that amount of time and getting soaked every few days? would a tarp help much?


Adventech is one of many brands out there for subflooring. Most T&G (tongue&groove) plywood that are worth anything is coated with some type of water resistant coating. They can get wet, but clear off the water everyday and you shouldn't have an issue. A tarp certainly can't hurt.


----------



## Bud Cline (Mar 12, 2006)

Advantech would be my material of choice. We work with it a lot around here. Advantech will survive some weather and delays if you don't abuse the privilege. Be ready to keep moving once the product begins. Advantech is treated somewhat but if it gets too wet too many times the panels will edge-swell a little. Even that isn't the end of the world. The swelled edges can be sanded if they are a problem for some reason.

You'll be fine if it is only a three week project but get it in-the-dry ASAP.:yes:


----------



## JCarsten (Jul 6, 2010)

Here's a link to Durastrand flooring- OSB, not plywood.

http://www.ainsworthengineered.com/all-products/floors/flooring/

I have used them in the past with good results.
Most likely not available at big box places- check with local builder supply (ABC, ProBuild, etc).


----------



## kwikfishron (Mar 11, 2010)

Bud Cline said:


> Advantech would be my material of choice.


And how much a sheet on Adavntech. Never seen it out here.


----------



## Gary in WA (Mar 11, 2009)

Regular OSB will edge swell= irreversible. Use plywood or an "enhanced product" pp. 2: http://www.utextension.utk.edu/publications/wfiles/W176.pdf
I drill holes in the shallow puddles soon as they form on a large house deck, if no plastic in crawl yet. Use a tarp (remodels I tie it to house tails, use ropes and pulleys for a giant Roman shade), cover the wood from the sun, etc.

Gary


----------



## Bud Cline (Mar 12, 2006)

> And how much a sheet on Adavntech. Never seen it out here.


Haven't a clue.

I just know that my builders that use Advantech compared to my builders that use OSB from the box stores cause me a whole lot fewer headaches when it comes to prepping a substrate for a tile installation.

It's hard to compare one new home to another because of the variables in weather exposure and time of year during construction but hands down Advantech performs better than the other products.

That's not to say I don't have any edge-swell to deal with because I do. It is the degree of edge-swell that seems to be a lot less with Advantech.


----------



## kwikfishron (Mar 11, 2010)

> Haven't a clue.


As long as the Tile Guy is happy.:notworthy:


----------



## Bud Cline (Mar 12, 2006)

> As long as the Tile Guy is happy.:notworthy:


I can assure you they don't use Advantech to keep me happy. They also don't usually shop at the big box. These are quality-minded builders that have had too many issues with a lot of the big box materials. I think they are convinced a better grade of material is available from a real lumber yard.


----------



## kwikfishron (Mar 11, 2010)

Bud Cline said:


> I can assure you they don't use Advantech to keep me happy. They also don't usually shop at the big box. These are quality-minded builders that have had too many issues with a lot of the big box materials. I think they are convinced a better grade of material is available from a real lumber yard.


 

Real lumber yards is all I know the closest Box to me is a hr.+ away. I’m all for quality materials as I’m sure Advantech is but have never seen that product used here. The new stuff usually has been out East for a few years before West gets it, and that’s just fine with me, let you guys be the test. You’ll never here me pitch OSB but yet all “real lumber yards” stock it. And to say if you don’t build with anything but Advantech means your not “quality-minded” is …….. America was built with CDX. Can’t wait for the 15 year review on the “Zip System”.:whistling2:


----------



## treerat (Feb 13, 2011)

thanks for all the help, sounds like I have solid info to work from, now! just need to watch the weather and make a decision from that of how fast I can get it in the dry to decide which material I will use. THANKS!


----------



## Bud Cline (Mar 12, 2006)

> And to say if you don’t build with anything but Advantech means your not “quality-minded” is ……..


I looked high and low in this thread and I don' see where anyone has said that.

So far the Advantech recommendation is the consensus - that's all.


----------



## bernieb (Mar 20, 2010)

Hold on Treerat.....just consider,you probably have already, but what about a concrete floor if your close to grade? If your planning on a ceramic tile floor, it may be the way to go.All depends how far from the dirt you are, and how cold of climate your in, and your ability to get a slick finish. Just a thought.


----------



## High Gear (Nov 30, 2009)

I've seen some Advantech take quite a beating with spring rains with virtually 

no effect .

http://www.advantechperforms.com/getting-started/product-locator.aspx

http://www.advantechperforms.com/dare-to-compare/video-comparisons.aspx


----------



## jimmy21 (Jul 2, 2008)

you could always paint your plywood before installing it. Wouldn't be that hard if its just a bathroom


----------

