screws spacing

[januwan]

My floor framing consists of 2x6 joists 16 inches on centers. I will be putting 1 1/8 playwood to match existing floor. I am going to use liquid nail and screws. Here are my questions.
What should be the length of the screws? I read somewhere it should be three times the thickness of the sheathing which in my case calls for 3 ˝ inch long screws (overkill?)

What should be the spacing between screws? Again I read somewhere 10 inches but on my old floor spacing vary between 6 and 9 inches?

Any advices greatly appreciated. Also if you have any tips for the first timer please let me know.

[Tom R]

I believe what you read, - - fastener should be 3 X the thickness, - - was talking about nails, - - for screws w/glue, I would say a 2 1/2" length would be plenty, - - every 12" in the field and every 6" on the seams.

[bkrahmer]

Instead of the 1 1/8 plywood, I would recommend using 3/4 wafer t&g subfloor with 3/8 particle board underlayment. You would save about $10 (using my local prices) for every 32 ft2, and have a smoother surface.

[VALENT]

I dont know about using your method Bkrahmer on 2x6 joists. I guess it would depend on the span.

[bkrahmer]

I could see the thicker plywood reducing deflection slightly, but it shouldn't be relied upon in the design, IMO. You are right though, it would depend on the span.

[januwan]

Bkrahmer
Thanks for the tip. I used 1 1/8 because I am extending existing subfloor that is 1 1/8. The span is 11-13 ft but the joists are above concrete slab (wavy) and are supported by “hills” in the slab so the real span is few feet.

Since I do it myself I have already save $3500. The original quote for frame of the 250 sqft floor (rim, joists, sheathing and relocating two registers) was $4500. I though it was excessive and decided to do it myself. With help of people like you it can be done.
I have already replaced 6 windows in my house and enlarge the utility door in my garage, I think I will be able to handle this project. Of course I am slow but it is fun.

Thanks again

[Cole]

The original quote for frame of the 250 sqft floor (rim, joists, sheathing and relocating two registers) was $4500.

Wow. :shock:

[januwan]

Exaclty :lol: