DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Flooring (http://www.diychatroom.com/f5/)
-   -   Installing Subfloor (http://www.diychatroom.com/f5/installing-subfloor-169281/)

RichardZ 01-16-2013 10:16 AM

Installing Subfloor
 
I'm installing 5/8" plywood over joists (16" oc). Can anyone tell me how long the screws should be?

Thanks,

Richard

hammerlane 01-16-2013 10:26 AM

Quote:

Originally Posted by RichardZ (Post 1094818)
I'm installing 5/8" plywood over joists (16" oc). Can anyone tell me how long the screws should be?

Thanks,

Richard

At least 0.0000236742 miles long

hammerlane 01-16-2013 10:39 AM

above is 1.5 inch...longer will not hurt but minimum I would go 1.5"

joecaption 01-16-2013 11:44 AM

You are using T & G plywood and constrution adhesive on top of the joist, right?
Why screws and not 8D ring shanked nails?

RichardZ 01-16-2013 11:48 PM

Hammerlane,

So 1-5/8" would be the minimum you'd go with. Would 2" be better (if so, a little better or a lot?)? And would you recommend stepping up to 2.5" screws?

Thanks,

Richard

RichardZ 01-16-2013 11:56 PM

JoeCaption,

The rest of the floor is straight 5/8" plywood, so I thought I'd stick with that. I will use construction adhesive (PL Subfloor, unless you have another suggestion). I'm using screws because I don't ever want this floor to squeak again -- may cost a bit more, but ...

At least, that's the plan. I'm open to suggestions, though.

Richard

epson 01-17-2013 12:08 AM

Quote:

Originally Posted by RichardZ (Post 1095422)
JoeCaption,

The rest of the floor is straight 5/8" plywood, so I thought I'd stick with that. I will use construction adhesive (PL Subfloor, unless you have another suggestion). I'm using screws because I don't ever want this floor to squeak again -- may cost a bit more, but ...

At least, that's the plan. I'm open to suggestions, though.

Richard

If you want your floor not to squeak then glue and screw with 2 long screws in most applications, #8 screws are sufficient. Screws should be driven at every joist on 12 centers and on 6 centers along the edges parallel to the joists. If you are counting, that results in the use of 43 screws per 4 x 8 ft sheet when installed with the long edge perpendicular to the joists, and 52 screws per 4 x 8 ft sheet when installed with the long edge parallel to the joists. Hope this helps.

RichardZ 01-17-2013 12:35 AM

Epson,

That helps a lot!

Since the long side of my sheets are going perpendicular to the joists, I take it that I should put my screws every 6" along the short sides/edges, and every 12" otherwise. Did I get this correct?

Thanks,

Richard


P.S. - When I check my screw count, I get 48 screws per sheet (9 screws on each end, and 5 screws for each of the two joists in between). RH

RichardZ 01-17-2013 11:16 AM

Epson,

Evidently, I need to repeat third grade math as I got neither the count nor the dimensions correct. If my count had been correct, I'd have 28 screws, not 48 screws. And that count was calculated for a 4x4 board, not a 4x8. Mea culpa.

Making the appropriate adjustments, I do indeed come up with 43 screws.

By the way, I really appreciate your including the screw count. It was absolutely a great double-check to make sure I got it right (not to mention useful in making sure one buys enough screws!).

Thx,

Richard

joecaption 01-17-2013 11:51 AM

The main reasons for using T&G is to get rid of squecks and stop and flexing between the joist.
Big mistake to not use it!

JazMan 01-17-2013 01:14 PM

A subfloor should always be T&G, otherwise you need a second layer of plywood, staggered and offset etc. Why is the rest of the subfloor square edge? There must have been a second sheet at one time.

When I re-fasten a subfloor I end up using a lot more than 43 fasteners, plus that's not counting the ones already there. I go 5-6" on the two ends and probably 8-10" on the other 5 joists of the full sheet.

Quote:

Originally Posted by epson
and 52 screws per 4 x 8 ft sheet when installed with the long edge parallel to the joists.

...And under what circumstances would that orientation be appropriate?

Jaz

RichardZ 01-18-2013 01:16 AM

JazMan,

You are correct: there's a second sheet.

Also, I will be adding an additional layer of 3/4" T&G plywood, staggered and offset, in order to raise the floor height to match the existing floor in the adjoining room. I plan on putting 1/4" underlayment on top of the 3/4", and then finish with a loose-lay vinyl sheet.

Question: when I screw down the 3/4" T&G plywood, do I use the same approach as for when is going to tile a floor, i.e., every 4" along the edge and every 6" within the field?

Thanks,

Richard

JazMan 01-18-2013 03:46 PM

Richard,

The fastening schedule is contingent on the thickness of the sheet being installed. 3/4" underlayment requires less than thinner underlayment. I'd say 6" around the perimeter and 10-12" in the field is fine. I think the specs call for 8" on the perimeter & 12" for the field. But I like to use more.

Jaz

rusty baker 01-18-2013 05:37 PM

Quote:

Originally Posted by RichardZ (Post 1096163)
JazMan,

You are correct: there's a second sheet.

Also, I will be adding an additional layer of 3/4" T&G plywood, staggered and offset, in order to raise the floor height to match the existing floor in the adjoining room. I plan on putting 1/4" underlayment on top of the 3/4", and then finish with a loose-lay vinyl sheet.

Question: when I screw down the 3/4" T&G plywood, do I use the same approach as for when is going to tile a floor, i.e., every 4" along the edge and every 6" within the field?

Thanks,

Richard

I would not use screws on the 1/4". Screws tend to make plywood that thin pucker. The puckers will show through even loose-lay vinyl. It is best to staple the 1/4" and don't use luan. It contains voids in the plys that can collapse.

JazMan 01-18-2013 06:56 PM

Quote:

I would not use screws on the 1/4". Screws tend to make plywood that thin pucker.
Oh yes for sure, no screws for the 1/4" Use the proper staple gun if you can get one or underlayment nails.

Jaz


All times are GMT -5. The time now is 08:58 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved