"Limp Arbor" wrote in message
...
My house was built in the 1970s when apparently there was a huge
shortage of either lumber or smarts.

2x8 joists, 12" O.C.,14' span
1x3 X bracing in the center of the span
1/2" plywood subfloor nailed with spiral nails - no glue
Oak hardwoord floors nailed perpindicular to the joists - the flooring
is short with most pieces less than 3'
Easy access from below in full basement

Floor bounces noticeably from normal walking, knick knacks rattle,
etc,

I tried on the other side of the beam with 16" O.C. 2x8 joists solid
blocking with little success.

I've seen 3 suggestions and want to know if anyone has tried them and
what the result was

1 Metal X bracing installed on either side of the current bracing
(splitting the difference between the center and the ends of the
joists)

2 Sistering the joists with glued & screwed plywood on both sides
(All plumbing & electric are either below the joists or parallel
to them)

3 Installing a plywood 'ceiling' in the basement glued & screwed to
the bottom of each joist.
(I guess the idea here is to make the whole joist sytem a giant
torsion box)




Would a beam or such run down the center with Lolly Columns every 8 feet or
so in the basement help ???