Someone refresh my memory, Is it 30 psf Live, 10 psf dead OR 40 psf Live, 10 psf dead. Nothing special, I’m trying to explain to my helper deflection for tile floor install. I can remember L/360, I just can’t remember anything else
Can’t I go 1 day without spilling my coffee?
Replies
Live loads tend to be 40 PSF for a residential floor load and the dead load typicaly is around 15 PSF, but it really depends on the house and whats in it. If you need help sizing a bean or floor joist for the floor I might be able to help.... L/360 will get you your allowable deflection....
You are asking about floor loads, right... I believe it varies from state to state, but in NC it is 10 PSF dead load and then sleeping areas: 30 PSF Live. Living areas: 40 PSF Live.
I design for 40# live in bedrooms upstairs and 50# live in kitchens and dining rooms where you have weight and activity that would be inconvenient on vibrating floors
dead lod can go to 15#
For tile, you want less deflection than your normal L/360 and tile adds to the dead load so for tile in a kitchen, design for 15# dead load and 50# live with deflection of L/480
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Dead load is the weight of the permanent parts of the building. It's possible to use the actual weights of the actual materials and figure out what the dead load really is.
Live load is the weight of people, furniture, whatever is in the building in the normal course of using it. It's not practical to figure out what the live load really is, so building codes specify numbers for live load that are sure to be plenty good and safe, even if the occupant is a fat guy who plays a grand piano and sleeps in a water bed. 40 - 50 psf for residential use is typical, libraries may be 250 psf because of all the heavy books, etc. The important thing is to use the live load numbers required by the code where you're building.
Another way to look at it is that dead loads are the loads you can know for sure, live loads are unknown, so you have to use some reasonable maximum.
-- J.S.
Edited 12/27/2004 7:24 pm ET by JOHN_SPRUNG