"Dave" wrote in message
om...
(Or How to correctly shim floor joists)

The existing 2x8 floor joists on my 50+ year old home are 7 1/2
inches. The 2x8's I plan to sister next to the old ones are only 7
1/4 inch.

Can someone tell me the approved method for shimming the difference
between the joists.

Why are you "sistering?"

If it is because the old wood has been damaged and you need "good" wood to
hold up the floor they you align the TOP of the new wood with the top of the
old wood.

If your floor sags too much under load or you would to jack it up and then
attach the "sisters" you should align the BOTTOM of the new wood with the
bottom of the old wood.

If you have BOTH problems, you should consider getting the next size up
(10") and ripping it to match the existing wood. Alternatively, you can
rip out some 1/2" (or whatever wood and glue it to the TOP of the new wood.

Wood tends to be more "spingy" is tension than compression so you add sound
stuff to the tension side of the beams (bottom, in your case) to stiff the
floor.

(Dave) wrote in
om:

(Or How to correctly shim floor joists)

The existing 2x8 floor joists on my 50+ year old home are 7 1/2
inches. The 2x8's I plan to sister next to the old ones are only 7
1/4 inch.

Can someone tell me the approved method for shimming the difference
between the joists.


I'm no expert but couldn't you just sister the joinsts so the tops of the
joists are level and the 1/4" difference is on the bottom (away for the
floor)?

make the new 2x8 tight to the floor

John Gilmer wrote:

"Dave" wrote in message
om...
(Or How to correctly shim floor joists)

The existing 2x8 floor joists on my 50+ year old home are 7 1/2
inches. The 2x8's I plan to sister next to the old ones are only 7
1/4 inch.

Can someone tell me the approved method for shimming the difference
between the joists.

Why are you "sistering?"

If it is because the old wood has been damaged and you need "good" wood to
hold up the floor they you align the TOP of the new wood with the top of the
old wood.

If your floor sags too much under load or you would to jack it up and then
attach the "sisters" you should align the BOTTOM of the new wood with the
bottom of the old wood.

If you have BOTH problems, you should consider getting the next size up
(10") and ripping it to match the existing wood. Alternatively, you can
rip out some 1/2" (or whatever wood and glue it to the TOP of the new wood.

Wood tends to be more "spingy" is tension than compression so you add sound
stuff to the tension side of the beams (bottom, in your case) to stiff the
floor.

Spingy??

Jeff


--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to
place the blame on."

"Dave" wrote in message
om...
(Or How to correctly shim floor joists)

The existing 2x8 floor joists on my 50+ year old home are 7 1/2
inches. The 2x8's I plan to sister next to the old ones are only 7
1/4 inch.

Can someone tell me the approved method for shimming the difference
between the joists.

Don't do what the previous owners of my place had done. They put the new
(thinner) boards down then used sawdust to make up the difference to the
lino floor. I kid you not!

Fraser.

(Dave) wrote in message . com...
(Or How to correctly shim floor joists)

The existing 2x8 floor joists on my 50+ year old home are 7 1/2
inches. The 2x8's I plan to sister next to the old ones are only 7
1/4 inch.

Can someone tell me the approved method for shimming the difference
between the joists.

A 2x8 is 7 1/4" deep. If you sister a new joist to one existing,
there is no need to shim. You'll be nailing sufficien number of nails
(or bolting) so they act as one without the top of the joist being
flush.

Yaofeng

A 2x8 is 7 1/4" deep. If you sister a new joist to one existing,
there is no need to shim. You'll be nailing sufficien number of nails
(or bolting) so they act as one without the top of the joist being
flush.

Unrelated, but recently I went to home depot and asked for a true 2x6,
something that was actually 6 inches wide. I thought I had seen some 2x4's
once that were actually 2 inches by 4 inches, so I figured I could get some
2x6's. Not true. No such thing. I had to get 2x8's and rip them down, a task
I despise because I am scared practically sh$$less of that table saw.

Ramble mode off now.

Maury
Wylie, TX

On Mon, 25 Aug 2003 22:35:36 GMT, "CMF"
wrote:


Unrelated, but recently I went to home depot and asked for a true 2x6,
something that was actually 6 inches wide. I thought I had seen some 2x4's
once that were actually 2 inches by 4 inches,

What you saw were "rough" 2x4's that weren't planed or otherwise
smoothed. I've seen these from small, local mills.

A normal piece of lumber is cut to the stated dimensions, planed,
shaped, dried, etc... The extra wood is removed during the milling,
and additional size is lost due to drying.

Barry

"CMF" wrote in message ...

I had to get 2x8's and rip them down, a task
I despise because I am scared practically sh$$less of that table saw.



Maury
Wylie, TX

How about a circular saw with a ripping guide?