Good morning, everyone.

I just received my 3/4" CDX plywood that will go on my slab. The stamp on the wood reads as 23/32" thickness, which is fine. But when I measure the thickness with a ruler, 17 out of the 20 sheets I purchased are 11/16, which is just shy of actually being 3/4" thick. Two are actually 5/8 inch thick and only one is a true 3/4". The subfloor will be glued down and secured with Tapcon screws. My HW flooring is 3/4" unfinished and I'll use 1 1/2 staples for nailing.

What kind of concerns should I have regarding the inconsistencies in the sheets of CDX? I'm wondering if the #15 roofing paper will make up for the size difference? Am wondering if I should go with #30 paper instead. My experience with other 3/4" plywood's is that they are a true 3/4". Are the size inconsistencies normal with CDX?

Thanks...Stan

I've gone through stacks and stacks of CDX doing subfloors and never had this problem. At the very least, I'd send the non-matching sheets back and insist they deliver a consistent product.

Don

With that said, Don. Is CDX always a little shy of a true 3/4"? And once I lay my #15 felt of #30 felt roofing paper to the CDX, will that make up for the 1/16". My main concern is weather my CDX, which, as mentioned, is 11/16" thick, coupled with the roofing paper, will give me enough depth to accept the 1 1/2" staples without hitting the concrete. Keep in mind that I"ll be using Bosticks Best under the CDX, which will raise add another 1/8" to between the slab and the CDX.

Thanks...Stan

Hi Stan,

One of the flooring pro's will give you better answers than I can.

Your CDX should measure within a fuzz either way from 23/32".

Don

Hi everyone,

Would really appreciate some questions on this topic. If the 3/4" CDX which actually measures out to 11/16, won't accept my 1 1/2 nail through 3/4 flooring, I'll need to come up with another alternative.

Best...Stan

It should not be a problem, seeing that you will be blind nailing at a pre-defined angle.

If you already have the nails you could try it out on some scraps.