Hello!

Got a (water-induced) warped floorboard. The "bubble" is about 18" or
less, and it lays down ok when you step on it. I tore up the carpet in
that area (getting new carpet later this week), and I'm pretty sure
that it's just the panel (OSB) that's warped, and that it hasn't
separated 'leaves' or anything.

So, depending on who you ask, sticking a couple of screws through this
panel into the floor joist will work temporarily or permanently. I'm
not sure what the floor joist is- 2x4, 2x6, etc... i'll have to look at
it. I'm guessing I'll want to put the screws in opposing angles- str8
up and down might cause the wood to pull up.

Putting washers on drywall screws is probably not recommended either?

Should i drill some narrow pilot holes? I'm afraid that if i stick a
few drywall screws in the joist it might split or something.

TIA for any comments.

According to phaeton :

Got a (water-induced) warped floorboard. The "bubble" is about 18" or
less, and it lays down ok when you step on it. I tore up the carpet in
that area (getting new carpet later this week), and I'm pretty sure
that it's just the panel (OSB) that's warped, and that it hasn't
separated 'leaves' or anything.

So, depending on who you ask, sticking a couple of screws through this
panel into the floor joist will work temporarily or permanently. I'm
not sure what the floor joist is- 2x4, 2x6, etc... i'll have to look at
it. I'm guessing I'll want to put the screws in opposing angles- str8
up and down might cause the wood to pull up.

Putting washers on drywall screws is probably not recommended either?

Should i drill some narrow pilot holes? I'm afraid that if i stick a
few drywall screws in the joist it might split or something.

Provided the floor joist isn't rotting out, screwing it down is the best
thing to do. Since it straightens out when you step on it, screws won't
have any trouble pulling it in and making the repair permanent - criss-cross
isn't necessary. If it's possible for it to pull up, the screw is too small!

Do NOT use drywall screws. They're too short and too thin. Overall,
the bite will suck ;-), and the floor board probably _will_ rise.

2 1/2" (or 3") #8 (or #10) decking screws are the best way to go, and
drive 'em in straight. They're cheap. 3" #8s can pull warped 1 1/2" decking
(ie: 2x6s) into line. Don't worry about that part.

It wouldn't hurt to predrill pilot holes - #8/#10 screws will not split joists
if they're in good shape and you hit close to the center of the joist, but,
predrilling pilots will make certain of it. It's more advisable with
#10.

I use 2 1/2" #8s for plywood and 3/4" floor sheathing. I reserve the 3" screws
for 2x lumber decking. #10 for extreme cases. #8 is by far the most
commonly used size.

Washers not necessary. Just countersink the head slightly with the driver.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

phaeton wrote:

Hello!

Got a (water-induced) warped floorboard. The "bubble" is about 18" or
less, and it lays down ok when you step on it. I tore up the carpet in
that area (getting new carpet later this week), and I'm pretty sure
that it's just the panel (OSB) that's warped, and that it hasn't
separated 'leaves' or anything.

So, depending on who you ask, sticking a couple of screws through this
panel into the floor joist will work temporarily or permanently. I'm
not sure what the floor joist is- 2x4, 2x6, etc... i'll have to look at
it. I'm guessing I'll want to put the screws in opposing angles- str8
up and down might cause the wood to pull up.

Putting washers on drywall screws is probably not recommended either?

Should i drill some narrow pilot holes? I'm afraid that if i stick a
few drywall screws in the joist it might split or something.

TIA for any comments.

Drywall screws countersink themselves no pilot hole needed, and it's highly
unlikely they will split any 2x anything. I would use at least 1 5/8" or
more.
--
"you can lead them to LINUX
but you can't make them THINK"