Omg, I haven’t got to the particle board yet. I hope it’s not glued!

thanks!

End of the day? I'm rootin' for ya.

1. 1. How far apart are the fasteners for the subfloor to joists to be spaced?

3. What's the local code call for. They can bring it up.

5. 2. Plywood underlayment over the subfloor, do I need to glue it down before fastening?

7. Doesn't hurt.

9. 3. How are the fasteners spaced for the new ply underlayment?

11. Typically one each square foot for overkill.

13. 4. What grade plywood do I get?

15. CDX is acceptable

17. 5. How much moisture is acceptable in the plywood underlayment before wood floor is installed?

18. Use a proper moisture meter than can allow for plywood results.

20. 6. If I get my plywood at Lowes, will they be able to tell me the moisture content of the ply.

22. Likely a no answer.

24. 7. Regardless of the starting moisture content at Lowes, or any Big Box
    store, would the ply be ready to accept hardwood installation in 4
    weeks? This is in a home that is already using heating/cooling.

26. Depends on moisture. Don't ignore the unpredictable.

28. If I install the plywood in 2x8' strips will that be ok? I am
    thinking if I can't get DH to help on this project I can cut the boards
    down to make them more manageable to handle.

30. Not necessary. That's more for optimum results where sub floor movement can be predicted. IE: moisture

Thanks Up Town! LOL. after lunch, I was chipping away for about a square foot, then went and took a nap. Then, woke up refreshed and started watching Youtube videos on how to get particle board out. I settled on one where the circular saw is used to cut around the periphery of each board and then across about 3 times for each board. It has been working pretty good.

I'm 1/5 done!

I'm on another break.

I always take a long time to get anything done because its always new, and I'm somewhat afraid of power tools. I have many though. My DH is always a standby, but he is supper busy with farming right now. Its a beautiful day.

BTW, the particle board is NOT GLUED :)

SJ McCarthy and Uptown, I got the particle board out. My next step will be to go through and use screws to fasten the old subfloor ply tighter to the joists. Is there anything wrong with that plan?

The subfloor looks like its 1/2". I was thinking about the underlayment and wondered if I should stick with the thickness of what was there, I believe it is 5/8", thats what the tape measure reads. But if the store sheathing reads 5/8" will it really be 5/8"? I'd like the floors to be smoothly transitioned together. The floor would have been nicely transitioned if I didn't take the particle board out. The last install 4 years ago they went over what they called 1/2 particle board with longer nails into the 1/2 ply subfloor. What's done is done in that install. This one can be a better install if I get the ply underlayment down at the right height. Otherwise I'll need a transition threshold. What do you recommend for transition?

You should use non-corrosive decking screws to fasten your existing subfloor along with your new panels. No need to worry about decaying when exposed to moisture. You need a minimum of an 1/8" expansion gap between each panel and 1/2" along the perimeter if, you are using 1/2" thick panels. Use longer 2 1/2" screws to anchor the panels into the joists and use short 1 1/4" to fasten it to the original subfloor.

Use a high performance panel for best performance, such as Advantech. It does not swell and lose it's nail holding capabilities like standard CDX or OSB will , when affected by moisture. Which means you will not have a loose, squeaky floor. If, you are using CDX, use an outdoor grade. It performs better under wet conditions.

Moisture content for subfloors should not exceed 12% for wood floor installations. The lower the number the better.

Thanks G&S, I do have deck screws and believe I have those lengths. I'll get them, if not. Thanks for the expansion gap specs too.

My flooring is not exposed to the elements. Its a bedroom floor, in an already build house. I wouldn't think I'd need a water resistant or exterior grade product. I was going to get plywood.

Inform me why I should get something other than a plywood product.

Roof leaks, pipes burst, foundations crack, appliances failing is common. Water will find it's way in, when it is time. Standard plywood subfloor panels are not moisture resistant. When it is exposed to water or moisture. The plywood swells and nails becomes loose, squeaks and buckles. You now have a loose subfloor and loose flooring. Swelling does not return to normal when dried. It is permanent. Which means panels would need to be replaced.

Using a high performance subfloor panel will help avoid these issues. It is stronger, stiffer, more moisture resistant, does not swell and has better nail holding power compared to cdx and osb.

Even if, you choose not to use a high performance subfloor panel. You should consider using and exterior grade cdx. Because, it has a higher moisture resistant compared to interior grade. Which means less swelling, less risk of your flooring to become loose and squeak and fail.

An acceptable grade panel is CDX exposure 1 grade plywood. If, it does not say "exposure 1" , it is not an industry standard plywood grade subfloor panel for wood flooring.

Here is the Lowes website for an Advantech sheathing at 5/8" which is exactly the thickness of the particle board I took out. Will this be thick enough or should I go thicker and have a threshold transition slanting up?

The next thicker is 23/32" I believe.

I assume I would still use deck screws to install. Im not going to glue.

I say replace like with like. If you are removing 5/8" then go ahead and replace with 5/8". There is no reason to do anything else.

thanks for the quick response. I'll buy tomorrow..

I have found 23/32 Advantech flooring panels at Lowes with list that the actual dimension is 0.688". The don't carry 5/8". The OSB and Ply they carry is 19/32", with actual measure dimension at 0.563". My old chip board is dead on at 5/8" when I measure which is 20/32" and translates to 0.625".

With these figures, I was going to go with the 23/32 because it is actually only 1/16" thicker than my existing chip board at 0.624". If I go with a ply or OSB in 19/32" I'm really getting 0.563" which is 1/16" thinner than my existing chip board. I figure either way, the change is 1/16" between underlayment and I might as well go a bit thicker with the Advantech. Also Advantech advertises that they don't gas off formaldehyde because of the type of formaldehyde used, and the encapsulating resins used to make the product.

I did get all the particle board up and installed decking screws to reenforce a few joist to the existing plywood subfloor where there was a squeak. Worked good.

Any thoughts on my plan to get the 23/32" Advantech would be welcomed. I will be getting 6 sheets to cover 168sf.

Also, my understanding of applying this Advantech underlayment, is that I only screw into the ply subfloor and not the joists. But the above comment by G&S floor Service on Sunday, is unclear to me. It sounds like G&S is saying to add screws to both the joists and the overall field of the underlayment (new install of Advantech over 1/2 ply). I would like clarification on this point.

Thanks.

I bought the 6 each of the 23/32 Advantech panels.

How do I orient them? Do I still go perpendicular to the joists, offsetting the seams from the 1/2 old ply subfloor?

DH wants to go perpendicular to the old ply, yet that would be parallel to the joists.

Then my 3rd issue, is listed in my post from yesterday, Do I attach these panels to the joists too, or the entire panel only to the subfloor? Meaning the only layer attached to the joists is the old ply subfloor.

I just called the lumber yard that is a very reputable business. The gentleman told me to run the Advantech perpendicular to the joists, using 2-1/2" screws at the joists. He said just stager the seams with the plywood seams. He said to act like the plywood isn't there otherwise. He said its standard to have 1/2 of the length of the screw into the joists. @G & S floors mentioned above to fasten the panels to the joists.