# 2x12x20 feet joist support ?



## Termite (Apr 13, 2008)

20' is the outer limits of the span for most #2 lumber species spaced at 12" centers. 

The addition of the pool table is a point load more or less, and a significant one. 

With the added weight of the hardwood and the pool table...Will it fall down? No. Will it be spongy feeling and have a perceivable bounce? Most certainly.


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## [email protected] (Nov 13, 2008)

Thanks for the reply. Any thoughts on how I can have the pool table and avoid the spongyness? Is the hardwood floor a significant factor? I was told today by the builder of the room (built 20+ years ago) that the joists have a load bearing of over 20,000 lbs.


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## Rkeytek (Nov 3, 2008)

Does the pool table have a slate table??
I would sister each 2x12 that is under the pool table and provide solid bridging between them at 36" o.c. to keep the as much rigidity to the floor as possible. The load bearing is great, but does mean they won't sag and if you jump in one corner of the room your glass of water will shake in the opposite corner??


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## [email protected] (Nov 13, 2008)

*2"x12"x20' floor joists-Rkeytek*

Rkeytek, thanks for the reply. Yes, the pool table has a slate top. Did you mean to say "doesn't" instead of "does"? And are you suggesting that it will sag and water on the other side of the room will move? Many thanks.


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## Rkeytek (Nov 3, 2008)

yes "doesnt", lol sorry

its really a matter of or comfort with the sponginess of the floor.

My parents house has 2X8 floor joists spaning more than they should, they have a slate pool table (probably 400#), my dad did add solid bridging and a plywood subfloor over the tongue and groove subfloor. walking normally you can't fell any type of movement, though a heavy foot, running, or jumping will cause the things on the book shelf and coffe table to rattle.

The structure won't colapse, but it is just not as tight as a properly designed floor system would be


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## [email protected] (Nov 13, 2008)

*2x12x20, 12" oc*

Thanks for your reply. Would the "bounce" or sponginess be reduced much if I were able to run a support beam 2' 6" - 3' in from the end of the joists so that their length was effectively cut down from 20' to 17' or 17 1/2'? Thanks.


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## buletbob (May 9, 2008)

I would install a steel beem under the middle of the floor joists I would hate to have the pool ball move as you walk around the table to shoot it.
BOB


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## Termite (Apr 13, 2008)

buletbob said:


> I would hate to have the pool ball move as you walk around the table to shoot it.


Oooh, good point Bob.


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## [email protected] (Nov 13, 2008)

*2x12x20---12 oc*

Many thanks to all. Do you think the bounce would be lessened much if I were to shorten the span from 20' to 17'?


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## buletbob (May 9, 2008)

yes you will less the deflection but it will still be noticeable. whats on your side is the 12"oc 2x12 @17'span not 24'


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