I have a question about weight support on second floor. I have a pool table that is approximately 450lbs, 3 piece slate. I weighed each piece and the table.
The room upstairs is 17’8" x 23’. I can see in the attic space that the floor is made with 2x12 on 16" centers. Label on the joist is No. 2 KD HT SYP. The underlayment is 1" thick. The table would run parallel with the joist if the room layout is as desired. The house isn’t very old, built in 2008.
Is 450lb sustained load safe for this floor?
Is the combined weight of a few players along with this 450lb table a concern?
Should I have this room inspected as a safety precaution?
P.S. The table is assembled with the center slab install. The other 2 pieces are on the same floor but not on the table. They are at 2 other locations positioned across the joist.
Houses are supposed to be built with the capacity to support a static load (pure weight, no motion, like jumping) of 40 lbs/square foot over the entire surface of the floor. So, your pool table will present a load that is something on the order of 450lbs/32 sq ft, or 14 lbs/sq ft, well under the design specs.
That doesn’t mean you can fill the rest of the room with aquariums, though…
A pool table covers a lot of area, and is supported by four legs. So each leg is only supporting 113 pounds. Round up to 120 if you want to. You wouldn’t worry much about four 120-pound people standing four to eight feet apart, would you? Or even four 200-pound people, for that matter.
As another comparison, an old-fashioned waterbed weighs 1,800 to 2,000 pounds, in an area not dissimilar from a pool table. Despite the warnings that a lot of landlords have, I’ve seen waterbeds in very old houses with no problem at all. The warnings are usually related to water issues, not weight.
So, having a pool table and several players is no problem whatsoever.
My table is 7x4 so it would be 28sq ft but i get the idea.
I do have one followup. Is there any concern for the legs punching through the underlayment? One side of the table (the 7’ side) would be almost on the joist, the other would not
I think there is very little chance of that happening, unless it was already seriously rotted. What can happen though is creating a permanent dip in the flooring under the table. Still, that would only happen with severe over-loading. 450lbs isn’t enough.
This gets into another issue. I still don’t think you have any problem, but concentrating weight into small footprints is different than the overall weight issue. When you buy a hardwood floor, the vendors will often tell you that women wearing stiletto heals might be a problem. Not because they are fat/heavy, but because most of their weight can be concentrated into a very small area, which can damage flooring. A 150 pound woman walking with heels that are less than one-half inch wide is a lot of weight in a very small area. But this still pertains to putting dings in a floor covering, not breaking through the flooring or subfloor.
I don’t think you have anything to worry about. How small is the footprint of each table leg? Unless each footprint is way under a square inch, I don’t think there is an issue.
Hi, can’t measure exactly but looks like the pad area touching the floor is 3 1/4"-3 1/2"
The flooring is carpet so I’m not worried about that. I do know from experience that the impressions are pretty permanent after a few years. I was more worried about a depressions or punching through of the underlayment but it sounds like that isn’t really a concern.
I’m guessing here that you have a 3/4 CDX plywood subfloor nailed down to your 2x12’s joists … this should be effective for transferring the weight over to the adjacent joists and even some to the joists next over … note that it’s not uncommon to put a layer of 1/2" particle board over the 3/4" plywood, the particle board doesn’t provide any structural strength to the floor but it does provide a nice smooth surface for what ever floor covering that’s used … in construction circles, the 1/2" particle board is usually called “underlayment” and the 3/4" plywood is called “subfloor” … the subfloor is structural, the underlayment is cosmetic …
it looks like there are 2 1/2" pieces of plywood on top of the 2x12 joist. I don’t see particle board but i can only see the end of about 2-3 feet of the floor in the attic space
I see no reason why this couldn’t be true … we’d still have the same effect transferring the weight to the joists … it would be difficult finding the little divots typical on the surface of CDX through carpet, near impossible if there’s padding … we’ll find out when we replace the carpet …
Ok, thank you for your post and for the comments of everyone. When I was a kid, I wouldn’t have given it a thought, in fact i had one of those old 2000 pound water beds in my parents house when I was 17. My parents were scared of it being there. I guess i have become like my parents
Seriously, thanks everyone. Appreciate the time and the knowledge!
This is quite unlikely. Standard pool tables are twice as long as they are wide. I suppose you could mean those are the overall dimensions and the playing surface is 3 x 6 feet with six inches all around for the rails and pockets. But that would be a fairly small table. They’re usually 3.5x7 4x8 4.5x9 with the latter fairly unusual for home use. For a slate table in three pieces I’d guess 4x8.
You can increase the footprints of your table by putting squares under it. Plate metal would be ideal which doesn’t raise the table very much. Coasters would work too.
If your table have adjustable feet under it it’s going to be an awfully small footprints.
