[denemante]

Hey all,

We have a finished basement that's about 12 feet wide and 30 feet long in one stretch. There are no supports - just the side walls.

Directly above is our kitchen and a breakfast nook. Obviously, all the counters are against the wall, and so is the fridge, stove, dishwasher, etc. We have granite.

I just installed a granite island and it's pretty big. You can "feel" the weight of the thing. It's nice.

But last night - I just got a horrible feeling that perhaps there wasn't an island there before because the floor couldn't hold the weight?

Then again, I'd never question it if 3-5 people were standing in the kitchen - that would be maybe 800 pounds.

Then I was thinking - what if I have a party? Put 15 or 20 people in the kitchen? With the huge new island?

Are floor joists designed to support this in homes? Pretty sure they are 2x10s.

 

[GBrackins]

so your joists are spanning 12'?

 

[denemante]

Yep - 12 feet. It's the original construction from 1998. Atlanta area. And there are many other homes in my neighborhood with the same floorplan.

 

[GBrackins]

I would have to guess at the wood species as being southern pine with the home being located in Georgia. 2x10 SP at 16" o.c. should be able to handle about 70 pounds per square foot live load and 15 psf dead load (85 psf total load), or almost twice what the code required live load (40 psf live load + 15 psf dead load) would be.

figure the square footage of your island and divide the weight by area to come up with a pounds per square foot for the island and see how that compares with the capacity of your joists. if the joists are not strong enough you could add additional joists or install a beam under the center of the island to help support the load.

hope this helps. Good luck!