Subfloor Options - My Findings

[Mattilac]

There is surprisingly little comparative data I could find on subflooring options other than random videos of guys jumping on different panels or what not, so I went ahead and picked up a handful of popular options and did some of my own comparing. This is far from a comprehensive test. I'm just trying to pick one for an attic flooring project. I figured I would share my findings in case it helps anyone else.

I picked up five different panels. All are 23/32" T&G and purchased from indoor lumberyards so they should be reasonably consistent in dryness.

Price paid on 12/28/23 (from lowest to highest):
GP BlueRibbon - $25.88
GP DryGuard - $30.00
LP Legacy - $39.88
Advantech - $57.38
GP DryPly - $58.48

Weight (from lightest to heaviest):
GP BlueRibbon - 65 lb
GP DryGuard - 66 lb
GP DryPly - 69 lb
Advantech - 72 lb
LP Legacy - 81 lb

200lb center load deflection (from least to most):
Advantech - 1.875"
GP BlueRibbon - 2.1875"
GP DryPly - 2.25"
LP Legacy - 2.375"
GP DryGuard - 2.875"

Advantech:


GP BlueRibbon:


GP DryPly:


LP Legacy:


GP DryGuard:


Random notes:
- All three GP products made some creaking noises as the weights were stacked in the center of the panel. The Advantech and LP Legacy panels were silent.
- GP DryPly (the only plywood sample) had pretty awful tongue and groove milling consistency. Sometimes centered, sometimes way off.
- GP DryGuard has a waxy black coating on the edges that rubs off and gets on anything it touches (namely your hands and clothes).
- LP Legacy printing was about 1" off on the panel I bought.

That's all I've got for now. If I think of any other comparisons to make, I'll update the post.

 

[theoldwizard1]

Great info ! Thanks !!

 

[MushCreek]

For an attic floor, seems like the GP Blue Ribbon is the clear winner at half the price of Advantech. I'd be curious to see how they hold up to water. Not an issue for an attic, but my Advantech floors were subject to weather for quite a while before I got my house dried in. Didn't seem to hurt it at all.

 

[NUTTSGT]

I understand the price comparison and weight of each sheet....but

The 200lb center load deflection ??? What is the rated span as stamped on each sheet ? 24" or 96" ? It appears that you are doing an almost 96" span, probably closer to 90".

Are you actually going to attempt to span that distance with the subfloor ?

 

[CraigStu]

Double checking w/ you on the GP Blue Ribbon deflection #. It is the only one w/ 4 digits after the decimal point. And those digits match exactly to the # above if you ignore the decimal. I know how I have messed up when creating charts w/ lots of data. If the BlueRibbon # is correct, it is the clear winner in $/strength.

 

[Mattilac]

The 200lb center load deflection ??? What is the rated span as stamped on each sheet ? 24" or 96" ? It appears that you are doing an almost 96" span, probably closer to 90".

It's an exaggerated test in order to have something to measure. I'm doing 24" o.c. but if I tested deflection at that span, I'd probably be trying to measure thousandths of an inch which would be much more difficult.

I don't see why the deflection numbers at 90" wouldn't translate proportionally to smaller spans. The point isn't the actual deflection, but the deflection relative to the other panels.

Double checking w/ you on the GP Blue Ribbon deflection #. It is the only one w/ 4 digits after the decimal point. And those digits match exactly to the # above if you ignore the decimal. I know how I have messed up when creating charts w/ lots of data. If the BlueRibbon # is correct, it is the clear winner in $/strength.

Yea, it's right. I just double checked the numbers. Coincidence that the last 4 digits match the Advantech numbers. I rounded to the nearest 1/16" and the GP BlueRibbon happened to land on 3/16" = .1875".

I'm surprised by the GP BlueRibbon too. I almost wonder if the sample I bought is an outlier somehow.

 

[Shoester]

This is terrific, thanks for taking the time to share you results.

 

[CraigStu]

....
Yea, it's right. I just double checked the numbers. Coincidence that the last 4 digits match the Advantech numbers. I rounded to the nearest 1/16" and the GP BlueRibbon happened to land on 3/16" = .1875".

I'm surprised by the GP BlueRibbon too. I almost wonder if the sample I bought is an outlier somehow.

Well thanks from me also. Who knows when I might need it, but I did a copy/paste and saved your chart in a word doc.

 

[strutaeng]

That's a good "visual" of stiffness vs deflection comparison, but I would admit I didn't expect that large of variations.

The deflections are actually to the power 3 or 4 of the span (cubic or quadratic), depending on loading (point vs uniform load) so span plays a huge role. And if you were to load these panels in the typical 16" or 24" o.c., I would expect the numbers to be much closer to each other, probably within rounding error.

There's a really good publication from the APA that I've used several time to check panel deflections: https://www.google.com/url?sa=t&sou...oQFnoECDMQAQ&usg=AOvVaw3eBdGqzbXMhqr7JF5uXEn4

I personally would not have any issues running any of those panels for an attic storage. Just pick one and move on with your life. Very easy for folks to get hung up on little things.