Calculating load on a floor

[akpolaris]

I am building a mezzanine that will be 32' X 12' with a kitchenette, bathroom and bedroom. Nothing fancy or extravagant. No tile products on the floor, Most likely a fridge and a microwave. The walls with be 2 X 4 lumber. The decking will be 2 X 10 and 5/8" T&G. I need to estimate a load for an engineered truss to span the 32'. Is there a rule of thumb to estimate this load??
Thanks

 

[DekeT]

I have a question for you. How are you going to know what is a good or bad answer?

 

[welder4956]

Google can be your friend:

http://www.ehow.com/how_7485788_calculate-floor-load-capacity.html

 

[akpolaris]

I have a question for you. How are you going to know what is a good or bad answer?

I am doing my own calculating the individual components and adding it up. just needed to bounce my figures against something else. Whatever goes in there will be over built.

 

[Chris705]

I would use 6x32x40....assuming one of the sides of the mezzanine is attached to a wall. One half the joist span will be supported by the wall & the other half by the beam. 40 lbs per square foot is what is acceptable for main floors in any residential home. That equates to 7680lbs. Uniformaly supported.

 

[wssix99]

Is there a rule of thumb to estimate this load??

No. Engineers go to school for a long time to learn how to do this. You best bet is to look up what the design load for your local code is and size to that. That process should be straight forward.

If you have a truss made, their engineers will do all the calculations.

 

[xyster101]

Call a building supply place. They can contact vendors of engineered I beams.
Chris is right at 40lbs per sq foot is a normal load. There is also an acceptable deflection in the joists, ex. .75" over a certain deistance. Usually the biggest complaints is vibration when installing joists. So proper bracing, gluing, and screwing the proper sub floor material is key.

I did a 26' span and wanted to put a 600lbs lawn mower and 500lbs ATV in the attic. I did 14" I-Joists (made in Canada) at 1' spacing as per the manufacturer. I went with AJS Joists from 84 lumber. I installed TG 3/4 sub flooring glued and rink shank nailed. In a home I would screw it down. They don't list anything over 24' on their chart, but I did 26' as per manufacturer recommendations.

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=ajs+joist+spans


My setup:

 

[DekeT]

I would use 6x32x40....assuming one of the sides of the mezzanine is attached to a wall. One half the joist span will be supported by the wall & the other half by the beam. 40 lbs per square foot is what is acceptable for main floors in any residential home. That equates to 7680lbs. Uniformaly supported.

Didn't say if it was commercial or residential.

 

[Chris705]

Thought OP said bedroom in his question. Bedroom areas are allowed to be 30 lbs per sf per international building codes.

 

[akpolaris]

thanks, I had found an engineered wood products site and calculated the dead load as around 12,000 adding up the weight of al the components and multiplying by 1.5. I had not factored in what Chris indicated that 1/2 the load is on the wall which is accurate. If I go with 12X32X40=15360 I think that I am safe factoring a live load of 15,000. What I was looking for was that 40# sq ft info. This should give me what I needed. I may put up a couple of short walls here at either end and reduce the total span. My goal was to not have anyone drive into a support post as well as having an open shop floor. Thanks a lot, good info