Which type of screws?

[Salty]

I need to run some screws into my floor before new carpet is installed. There are some areas that squeek and I'd like to fix that beforehand. When the floor was put down, they just used nails. From in the basement, I can see the nails that missed the joists and they do not appear to be ring or screw shank nails.
The floor is 3/4 particle board over 1/2" subfloor.

Also, if there are places where the tackless is loose but still stable, I am thinking that maybe I should use some screws to re-attach it rather than nails. I removed 2 sections in front of the entry door where I am going to install some laminate flooring. The nails pulled the particle board surface up and I had to fill the holes. I know particle board is brittle and gets more so as it ages. I want to be prepared with fasteners if there are areas where the tackless needs attention.

Any suggestions would be helpful and much appreciated.

Thanks.

Salty

[cabinetman]

I would use coarse thread (all the way to the head) flat head phillips screws, or square drive heads. Choose the correct length. Pilot and countersink, and just bump up tight with a cordless, on the slow speed. Don't drive them in fast.
.

[eccentrictinkerer]

Check with your hardware guy at the BORG. There's a special screw and fixture available to drive the screw (it has two thread pitches so it pulles the floor board tight to subfloor/joist.

After driving the screw, you break the screw off just below the surface of the floorboard.

Check this link.

[Slik Geek]

I had some squeaky spots five years ago that I dealt with with regular coarse-thread deck screws. Didn't have time to be picky - I was slipping in between the installers doing tear-up and the new padding installation.

I just drove the screws (no pilot / countersink) through the particle board into known joist locations. It has worked like a charm up to now. I may have gone overboard on quantity because I wanted to make sure that I NEVER heard those squeaks again. I probably had screws every two inches.

[Hellrazor]

Beware: Check what/where electric wires,etc are in the joists before you start nailing/screwing the floor down. Size the screws,etc wisely..


The last time I renailed a subfloor I used 8d ringshank nails in the framing nailer. No squeaks after 4 years.

[Salty]

Thank you Mike. I was considering using an air nailer as I sort of recalled that Paslode made a ringshank nail for them. The whole floor needs renailed or screws installed. I'm not sure my knees and back could take that much using screws. I'll see if the local places have a nailer for rent before I'd invest in one for just this one time use.

[Hellrazor]

I know they make those 8d ringshanks for my PC framing nailer. I use them all the time for sheathing, etc.

[Salty]

Found this on a webpage. I think this rule is wrong. There is no way I am going to use nearly a 4" long nail to renail my floor.

As rules of thumb,

In fastening sheathing, shingles, clapboard, etc., the nail should be at least three times longer than the thickness of the sheet or board being fastened with it.

[JimD]

I think an inch of bite into the floor joists will hold fine. 2 inch should work for your application. It may be a bit less than an inch of bite but not a lot. A clearance hole is the only way I have found to get a good clamp of the pieces together. Without a clearance hole, I would be worried that the threads would hold in both the subfloor and the joist and maintain the space between the two. 2 1/2 inch screws would be plenty IMHO.

I use coarse thread drywall screws for most woodworking. There are better screws but they are good enough for my projects. You can break them, however. I drive them with a cordless but often use the high speed setting, with the clutch set tight enough to pull things together but light enough the screws do not break or strip. Deck screws are a bit tougher and I like the type with the combo phillips/square head with the special bits they come with.

Jim

[Salty]

If using screws, I agree that a clearance hole or pilot hole is necessary. That is the only way to be sure the head of the screw can pull down on the top layer and make a tight fit.
However, if my 240# weight can compress the top deck then a ring shank nail can keep it there. I think I could put in a lot more nails with an air gun than I can drive screws.
I may put some screws in the squeeky areas and then drive nails in the rest.

[JimD]

I know it is true in sheetrock and I think it is true in plywood that the strength of the material being fastened is the limitation, not the fastener. I challeneged my builder to not use smooth shank drywall nails to cut down on the nail pops. He did what he wanted and then showed me that a number of the pops were screws, not nails. Drywall crumbles pretty easily so you will make a hole in the drywall before you extract even a smooth shank nail. I suspect plywood is much better than drywall but you would probably still get a hole in the plywood before extracting a ring shank nail. If that is true, then it's just an ease of installation thing. Either will hold as well as the other because the plywood is the limitation, not the fastener.

Jim