Framing question

caballoviejo · #1 05/19/05, 03:21 PM

For floor/ceiling joists I've been using 2 X 6s on 1' centers. Well within the maximum spans for the grade of lumber I can readily get. In one section of the ceiling/2ndfloor with a slightly longer span I would neet to get number 1 southern pine in order to meet the need span. I can't get better than number 2 grade here for SYP.

Question: can I use 2X8's for these longer spans (which will easily meet the span indicated in span tables) even if I notch out 1.5" at the ends where they rest on the top plates? Doing so would preserve my entire upper floor on one level plane.

Running Arrow · #2 05/19/05, 04:42 PM

Quote:

Originally Posted by caballoviejo

For floor/ceiling joists I've been using 2 X 6s on 1' centers. Well within the maximum spans for the grade of lumber I can readily get. In one section of the ceiling/2ndfloor with a slightly longer span I would neet to get number 1 southern pine in order to meet the need span. I can't get better than number 2 grade here for SYP.

Question: can I use 2X8's for these longer spans (which will easily meet the span indicated in span tables) even if I notch out 1.5" at the ends where they rest on the top plates? Doing so would preserve my entire upper floor on one level plane.

If you knotched out 2 x 8's 1.5" at the ends, you have just created 2 x 6's for the price of 2 x 8's. Lumber grades relate to the straightness of the grain as well as the size (diameter) of any knots and quantity of knots. It is possible that #2 grades if carefully selected "might" equate to some of the #1 grades out there, but no guarantee. Another possibility is to BLOCK under the knotched out 2 x 8 so the bottom of the 2 x 8 was also supported, not just the knotched out portion.

moopups · #3 05/19/05, 06:07 PM

Run doubled 2 by 6's with a plywood fische plate between them at least 1/2 inch thick.

A one quarter inch mild steel plate if your inspector is a turkey.

agmantoo · #4 05/19/05, 07:10 PM

Notch the 2x8's, the notching is an old acceptable practice in years past. The center span is where the problem exists with the 2 x 6's

caballoviejo · #5 05/19/05, 07:54 PM

Quote:

Originally Posted by agmantoo

Notch the 2x8's, the notching is an old acceptable practice in years past. The center span is where the problem exists with the 2 x 6's

That's what I was thinking.

The only inspector on my place is me - and I care more than any inspector could. Double 2 x6s with plywood sandwiched in would be overkill for the needed span, and expensive and time consuming compared to elsewhere.

If necessary, I could attach a 2 X 4 or 1X 4 frieze board under the 2 X 8's by nailing it to the double top plate. It would double as moulding.