[HenryMac]

Don't use deck screws, they are not structural. Use Simpson Strong-Drive® WSV Subfloor screws. More data HERE

We installed a few thousand of these using a Makita corded drill... these screws are great.

"... testing indicates that the WSV Subfloor screws have lateral, shear and withdrawal values that exceed those of 10d common nails, and diaphragms built with WSV Subfloor screws meet or exceed the strength and stiffness of wood frame diaphragms built with 10d nails."​

 

[HenryMac]

Deck screws are fine….because there is no lateral force. Save your $$

Show us in the code where it states you can use "deck screws" for subflooring. You won't find it, and there is a reason for that.

Want to save money.. use ring shank nails.

Plus, depending on which "deck screws" you use they have a large shank, and small thread height. That will split the subfloor at every butt joint. Now what have you gained?

Might as well do it right, using screws specifically designed for the application.

 

[HenryMac]

Well, I can't find any screws at either big box store specific for subfloors except for some collated and I'm not buying attachments (yet).

I did see these at Lowes; I figured 2.5" was as long as I needed for 5/8" ply. Perhaps I can go shorter?
Any of these preferred?

View attachment 670477 View attachment 670478 View attachment 670479

Thanks!

How thick is the total subfloor thickness? I'm betting it's more than 5/8".

Ours had 3/4" thick plywood & 1/2" plywood. So that's 1-1/4" thick. I'd use 2-1/2" where your screwing through the plywood down into floor joists, and 2" where your just screwing the 2 plywood sheets together (not screwing down into the floor joists).

As far as spacing, I used the "nailing" configuration shown in the bottom right of the detail below.

 

[HenryMac]

Subfloor is 5/8” plywood nailed with spiral nails into 2 x 10s.

Yikes.

2" screws should be fine then.

 

[HenryMac]

Steve and Henry, thanks.
Pulling the few were a pita as you said. A lot of squeaks in this floor and other rooms. The spiral nails seem to be working themselves loose, many are proud of the surface.
What are your thoughts on them working loose again if I set them? They’d easily telegraph through vinyl planking.

How long are you planning to keep the home?

Short Term: Nail set them as previously discussed. Maybe recess them 1/4"​

​

Long Term:​

• Pull all the nails and replace them with screws -or -
• With only 5/8" thickness the floor will be spongy. You could always add a layer of 3/4" over the 5/8". That will make the floor rigid and bring it up to the 1-1/4" min. thickness if you ever wanted to install tile. Of course you'll likely have to trim the bottom of the doors, etc.

 

[HenryMac]

I assume my daughter and husband will be there for long time. I agree with you thinking but dread pulling the spiral nails out; they don't come out easily.
This is a bedroom and adding thickness would likely be a problem the door to the hall with transition heights.

Transitions are available, or can be made. I'm just finishing up some that I made. I agree, it's a lot of work, but a nice solid floor is something worth the work.

Good luck to you on your project.