Expert: Dave Johnson - 8/10/2009

Question
We have a 16 foot spanned 2X6 joits(s) @ 24" center.

The span is supported by a 4X6 perpendicular crossmember which is in turn supported to ground by 4X4 posts spaced every 6 feet.

The length of the 4X6 is about 18 feet.

In order to remove the 4X6 cross member, and the 4X4 posts,I would like to re-enforce the existing 2X6 joist(s)using a 1/2" X 5" steel plate appendend to every other joist using 1/2 bolts spaced at 24" centers and supported at each end of the existing joist.

Is there a span table available that would provide support equivalency.

Would this be equal to a 2X10, 2X12?

Thanks,

Gerry

Answer
Hi Gerry,
The added steel won't work, it will be still subject to twisting under load, and once this happens, "down she comes".
There is no way any steel attached to even both sides of ALL the joists would work, there isn't enough height to your members nor are they close enough.(sorry)

Go to a site called American Wood Council and ask for "joist spans and loads" there is an abundance of info there on just what you're needing.
If you run into the word "incised" it just means that the lumber has been roughed up or made porous to accept preservative...not anything you need...

Best of luck, and if you want more, mail me again...
Dave