Sturd-I-Floor plywood is manufactured to have a surface that is smooth and high-impact resistant so that it can be used as a one layer subfloor/underlayment and carpet or resilient flooring can be placed directly on it. Bond classifications are Exterior or Exposure 1.

"Exterior" has a fully waterproof bond and is intended for permanent weather exposure

"Exposure 1" has a fully waterproof bond and is designed for use where the construction process will subject the plywood to "long periods of weather exposure" before they are fully protected.

The thickness can be from 19/32 to 1-1/8 inch.

Check the grade stamp on the plywood for the exposure rating. Call the supplier, then call the manufacturer. Somebody owes you an explanation.

mightyanvil, Thank you!

Plywood subflooring seems to be almost extinct around me, and I was really set on using it.

I spent alot of time and money to assemble a floor framing structure that was as close to perfectly level as could be. The main floor is going to have a couple very open areas where the hardwood flooring would be fully viewable with much light.

Am I rationale in wanting to stay with plywood? any other brands I should consider?

For sub-flooring these days, I'd be hard pressed not to use Advantech OSB. It seems to hold up under torrential rain/weather alot better than any plywood I've ever used. Don't mistaken Advantech OSB with just plain OSB as its night and day.

We used the Sturdi-I-Floor on our build. Since we started in the spring, our wettest season, I anticipated rain delays and I wanted to limit any water problems with the subfloor, so after the subfloor was installed I went out and sprayed it down with Thompsons water seal. Even though at times over the next month we had a lot of standing water in the house that required us to drill holes through the subfloor to drain it, the subfloor showed little damage. In only a few spots did a little delamination/swelling occur, which we we able to sand/fill flat these areas before installing the flooring.

Sealing it is not supposed to be necessary. I would think that the Sturdi-I-Floor in your case would have performed better than it did after only one rain. It is supposed to be okay under such conditions. I'd have someone check it out.

I second anthem, we have Advantech. After rain our house felt solid even when it was just framed. We don't have that echo sound that I usually hear when I'm wandering thru an unfinished home. No squeaks either. I'm really happy with it. Nice and solid with a 50 year warranty.

For reasons beyond my understanding, the lumber yard is adamantly against contacting the product manufacturer. After a few heated discussions and site visits, they agreed to credit me for the subfloor.

I am now faced with making a choice for another subfloor. The yard I have dealt with does not carry a high end plywood T&G product, which I really want. Has the plywood market for subflooring really dissappeared? Am I being dense not caving to an OSB product?

Thanks for the opinions.

OSB with preservative treatment (Advantech) is fine as long as you don't plan to adhere flooring materials directly to it.

I would be suspicious about the lumberyard not wanting you to contact the manufacturer. If you send me a photo of the grade stamp I can find out if it is legitimate.

Interesting mightyanvil, I will try, thank you. Very few sheets of this product even have a stamp that is remotely legible.

I was able to remove half of the installed Sturd-i-floor this afternoon, it is no fun. The subfloor when looking at the edge once removed, was literally sagging between joist. On some panels the lower/bottom ply is bulging and delaminating downward toward the crawl space. Another thing that showed itself, is that in many areas of swelling there was a void in the lower ply. This was also evident while using the crows foot to remove nails as the crows foot would sink into areas where the ply's had voids. Many nails were pulled through the top ply by the swelling, and all this was after one afternoon of rain.

I will be looking at a 7 ply exterior grade product in the morning from a different yard.

Why?

Advancetech and other advanced OSB products are proven technology, while the APA continues to degrade the quality standards for plywood.

Please don't let the 'this is how they used to do it in the old days' thinking interfere with what builders are telling you right here on your thread. Plywood products are NOT superior to OSB products. Yes, some individual types of plywood ARE better than some individual types of OSB. But a class generalization of panel products is, as you alluded to in your second post, an irrational idea of a class of products. You used a 7-ply plywood product that failed, and saw their warranty reaction, and now you're going to replace it with a.....another 7-ply plywood product of unknown warranty reaction. Ummmmm.....don't they consider doing the same thing again and again and expecting different results to the definition of crazy?

Builders are telling you. Advancetech. You are not 'caving'; you are spending your money needlessly to try and prove to yourself that your bias is correct. No, I'm not trying to be an A$$...I'm pointing out that you're spending YOUR money to prove something that there's no value in trying to prove.

Check out what we said, several times. Then again, it's your money and time, not ours.

This tip from my wife' uncle;

After the subfloor is on cover with a tarp, I used the green on one side brown on the other, and build your walls right on top of this.
Leave the tarp on till your finished floor goes on and then cut around the perimeter with a utility knife.
All the rain has been kept off plus the floor is clean of all paint and mud splatters.

I see your point and observation, thank you for taking the time to offer it up, as it may sway me.

I have a few things pulling me toward plywood,
1)Is my desire to reduce the outgassing in my home as much as possible for aquired health reasons.

2)My being told by several proffesionals that plywood will offer more support to a minimally designed floor joist system (2x8xll's) as well as hold the nails better in hardwood flooring, which several manufacturer sites also elude to.

3)The perception I have of a plywood being superior as I see it being used in many of the higher valued homes. I know this is very subjective and not a good indicator of the products performance. I built my own forms for my monolithic foundation additions with a 7 ply exterior grade AC, US made. They have been used several times over and left behind a shed in the wheather for two years since I baught them new, never oiled. They literally, aside from some bowing have zero delaminations and surface imperfections, I was very surprised.

I will be checking out the advantech product before I purchase anything else. Thanks again for the reality checks, sincerely.

It's hard to believe that this product was properly rated. I strongly suspect fraud.

Here is a link that might be useful: counterfeit APA grade stamps

Very interesting read mighty, and I just happened to be next door to Tacoma, WA.

The article mentions incomplete or missing grade stamps, that perfectly describes my situation. I had a very hard time finding any grade stamps I could make out to verify "exposure 1".

Is every individual panel supposed to have a grade stamp? seems only logical.

I was talking with a project manager who was comped for the same product in a 240 unit condo development. He reccomended a 3/4" ACX T&G crossbanded plywood. He has access to the product and would extended me his cost which is $6 more a sheet than what I paid for the original sturd-i-floor product.

Despite what the lumber yard feels about the situation, I would love to hear what the manufacturer or supplier has to say about the subfloor problems and the grade stamps.

I have been a plywood proponent for a long long time. I still am a plywood proponent over OSB. However, for sub-floors, I rank the advantech OSB TG product over anything else out there. It can take copious amounts of water without any expansion at the joints and looks as good after 3 months of hard water as when first laid down. I can't say enough about how it handles moisture.

Unfortunately it is still an 'OSB' product and as such people clump it in with OSB. Most anyone who has used it would never go to something else. The only drawback is that it costs a bit more than osb and plywood. I seriously recommend that you take a look at the advantech OSB sub-flooring product as its IMHO the best thing out there.

The product I have does not have the span allotments on the grade stamp. Many of the sheets have no stamping at all, APA or manufacturer. None of the stamps are complete or very legible and all are on the bottom side of the sheets.

My long time munincipal building official showed up and could not believe what he saw.

I made another showing at the yard for answers and could get none, they are still refusing to get the manufacturer on board. I was actually enlightened to the fact the product I have has been there awhile and the source is unknown. This yard has went through a recent re-brand and corporate affiliation.

I told them my desire for manufacturer intervention, and would give them through the day to initiate it or I will.

One thing I'm confused on, as is the yard, is a product branded underlayment (my sturd-i-floor) ok for use a subfloor/sheathing?

The Georgia Pacific website (branded manufacturer of my sturd-i-floor)clearly talks about the underlayment being installed over an aproved sheathing. I thought the product I have was made to go on top of the floor-joist?

A product called Plitanium went down on the house I have under construction. I've been pleased, but Alabama is going through a huge drought right now so it really hasn't gotten wet. I've been pleased with what I've seen.

After all was said and done I'd probably called the manufacturer with info on what happened and who you bought it from. It sure sounds like fraud. Save others the headache you just went through.

GP Plytanium Sturd-I-Floor is definitely a sub-floor but because it is intended to be used as a single layer it does not necessarily need an underlayment over it for carpet and tile. Therefore, it would be inaccurate to call the basic product an underlayment but you could call it a combination sub-floor/underlayment. At any rate, it would be a waste of money to use it as a true underlayment over a sub-floor. The Sturd-I-Floor designation essentially means the top layers of the sub-floor are stronger and free of voids so an underlayment isn't absolutely necessary.

Plytanium sub-floor panels are also sold with a water repellent coating called DryPly. I suspect this is in response to AdvanTech.

Here is a link that might be useful: Dry Ply

If I am not mistaken, "Plytanium" is a GP trademark for some of their plywood products, and Sturd-i-floor is an APA trademark for the combined subfloor/underlayment system with T&G edges. Assuming no fraud in the grade stamp, all "Plytanim" comes from GP, but "Sturd-i-floor" can come from any of a number of manufacturers who use APA grading standards.

If the grade stamp is counterfeit, then of course all bets are off.

Thank you mightyanvil for the product designation explanation. No one I have been in contact with was sure what it meant, sad.

After photo's were circulated of the bad un-graded product, I recieved a phone call from the yard's supplier/wholesaler (out of state). He told me he was initiating a claim for my faulty product case, not sure what they may involve/cover. The yard then had a guy show up and photograph everything.

I have all of the sub-floor removed, what a job. The construction adhesive actually pulled up and splintered the tops of some of the 2x8 DF joist. Now I have to figure out the best method for removing the adhesive and ply pieces left adhered to the joist tops. Any advice? Do I need to get back down to bare wood or will the glue adhere to itself (residue) ok?

Thanks to everyone for your insight and help.

The final word on my product problems were exactly as mightyanvil had suggested, it was counterfiet. So I wanted to fend off any sugggestion I may have left that my situation was an example of Georgia Pacifics legitimate products.

The re-imbursement process has been cumbersome but it does appear between the wholesaler (Hampton) and my retailer that I will recover all expenses, though I have lost nearly 3 weeks trying get traction with this issue.

You should be compensated for all your losses including lost time. The suppliers should be happy to settle out of court and avoid possible punitive damages and/or criminal charges. APA (the Engineered Wood Association) says they aggressively pursues these cases so be sure they know about it. Everyone concerned with the sale and delivery knows what APA rated plywood looks like so they obviously knew what this material was and intentionally participated in consumer fraud.

You should have a lawyer representing your interests.

It has been an uphill battle with the retailer, every step of the way. They do not seem the least bit concerned about the fact they sold me the product.

After your prompting mightyanvil, I will contact the APA in the morning. In hindsight, I should have started there.

Thanks again for the assurance and info.

I doubt they will take you seriously until you get a lawyer.

i used suck-i-floor also. The sheets were not square and the 48 inch cut was everywhere but 48 inches.not 1 sheet mesured 48 inches or did i find a single sheet that was square. I will never use sturd-i-floor again.