What PSI Load Rating for Loft

[duwem]

I plan to put a rec room up there with tv, couches, pool and air hockey table, maybe a fridge etc. Then the other half will be for storage, maybe some rooms like a paint room etc.

All that doesn't sound like anything more substantial than residential house loading, but the question is the load for the storage part.....not sure how I would know how much weight could end up up there.

Right now they have it designed for 125 lbs per square foot loading. What kind of stuff can I put up there at that load? Is that possible overkill, not enough?

Thanks

 

[Dr Stan]

Right now they have it designed for 125psi loading. What kind of stuff can I put up there at that load? Is that possible overkill, not enough?

Thanks

Is that 125 psI or 125 psF?

 

[duwem]

They said 125 lbs per sq foot (Edited the first post)

 

[73RR]

125 psf is overkill for all but the most serious warehouse. That's like 3000 lbs on a small 4x6 pallet.
I'm curious what the framing looks like...

 

[duwem]

When I asked if price would fluctuate a lot going up or down from there he said there would be additional engineer cost to change it...guess I will have to understand that cost vs cost savings of reducing the loading.

They do have details on the beams and floor joists/flooring on the plans, will look that up and post it.

 

[theoldwizard1]

What is your span ?

Posts under each joist.

 

[duwem]

30' span with an I beam at 15' and pole

On below image, beam goes up and down, floor joists side to side.

 

[theoldwizard1]

30' span with an I beam at 15' and pole

Steel I beam ? Posts on each end ?

Each joist needs to be supported at each end NOT just attached to a ledger lagged to the side wall.

 

[Chris705]

"Right now they have it designed for 125 lbs per square foot loading. What kind of stuff can I put up there at that load? Is that possible overkill, not enough?"

Most likely overkill, but you need to describe more of what you might be looking to store up there? Residential living areas are typically designed at 40psf. Business offices are typically at 100psf....(think of heavy filling cabinets). If you were going to be storing piles of metal tools and auto parts stacked high on top of each other or on shelves then maybe you would want the 125psf....Or you could limit them (shelves/high piles) to the ends where the joist bearing points are....

 

[duwem]

I would like the auto parts, gokarts compact tractor attachements etc but might be chicken to put stuff up there regardless of what its rated for?

 

[bczygan]

Did the designers consult you about what would be stored up there before they specified 125#/SF? Or did they just pull the number out of their ***?

That is real heavy loading. And iis that live or total load?

A lighter load might enable you to eliminate the column or go to engineered lumber for the beam, making construction easier.

If they didn't ask, then it's on them to recalculate.

Bill

 

[duwem]

I told them I wanted a few steps over residential loading. I'm meeting with them later this week again to discuss.

 

[LX-Markham]

We design parking garages for 50psf. Assembly areas (think mosh-pit) for 100psf.
125psf is extremely heavy.
Better clarify with the designer.

 

[rlitman]

I told them I wanted a few steps over residential loading. I'm meeting with them later this week again to discuss.

We need to know what sort of ceiling is underneath this. Load is only half of the equation. The other half is deflection. Too much deflection, and a ceiling might show cracks, when open joists would still be fine.

The same floor that can just support 125psf with little enough deflection to protect a plaster ceiling should be ok for heavy equipment driving on it without that ceiling to contend with.

But 125psf where that equals static plus dynamic load, and is the design to failure might not be that massive at all.

 

[tinysparky]

you have already answered your own question. You asked the builder to engineer it more that what you need......he said...ok....125psf....

Unless you are putting a hotub up there.....and I am talking a big one......you should be well within your margin limits.

I know this because i stayed at an Holiday inn last night....

 

[theoldwizard1]

According the span table I have ...

30 psf live load is "typical" for residential and you would need 2x10 #2 SPF/SYP 16" O.C. for a 15' span.

At 50 psf live load, you will need 2x12 #2 SPF/SYP 16" O.C. for a 15' span.

 

[duwem]

Here is what they currently have.

 

[duwem]

It got quiet in here...

 

[Chris705]

A couple of thoughts as I look at your response and the posting of your building section. No ceiling is called out so we are not being concerned with deflection....if you want to stay with 125psf that is a solid floor. I am not going to look up the load charts to confirm that 14"TJI and the steel beam are rated for that....What I think is that 14" TJI are not all that expensive, you have an engineered set of plans and based upon not knowing exactly what will be stored up there I'd be inclined to roll with it. The steel beam will be flush with your ceiling line which is helpful (nothing hanging down). If you want to store your implements up there go ahead.
A couple of comments based on other things I see on the plans....with that type of load capability on the second level then I would really like to see the studs lined up with the floor joists so I'd urge you to make them 16"oc at this area...Also I see they called out a broom finish for the slab....is that really what you want there, typically troweled smooth for interior slabs to make cleaning/brooming easy.

 

[duwem]

Actually they are now adding headers on either end of the loft so I can drive in from both directions. I asked for this day one but just recently got a new sales guy and we re-discussed it and found out it was never in there. I'm meeting with him tomorrow to review those plans and the building cost with the loft being an option.

Floor is done, it was trowel finished.

LOT more detail in here:

http://www.garagejournal.com/forum/showthread.php?t=330490&highlight=raised+roof+ICF+walls

I'm kind of with you on the "if its already engineered and materials aren't that much cheaper to downsize, why not go with it"

 

[Jon_E]

14" TJI's @ 16" OC for a 15' span are going to hold a hell of a lot of weight. Easily 125 psf. It appears you have good support on both ends (bearing length) so I would be comfortable with that. You can gain 2" of headroom by going to an 11-7/8" TJI but cost-wise, what's the point?

I designed my second floor for 100 PSF, but I plan on storing a large amount of lumber up there, so I needed the heavy floor system. I have rough-sawn 2x12 spanning 12' @ 16" on center.

 

[GMCGarage]

the 125psf is a "light storage" spec from the code. "Heavy Storage" is 250. For comparison, library stack rooms are 150 psf. A library stack room is defined as 12" shelves back to back, 7.5 feet tall, seperated by 3'-0"

You asked for a couple steps above residential. 30 psf would have been step 1, 100 psf step 2, and 125 is step 3.

Kudos for planning ahead and asking for more storage capacity and actually hiring a engineer to design it.

It looks like your 14" TJI would be the TJI 360 series. At max load, the deflection would be about 1/2" max with those joists.

Verify the series of TJI they are using, dont let the contractor just pick any old 14" TJI, get the one that meets your design load.

 

[duwem]

Well I signed on the building last night. Went with the loft. I'm wondering what would be a recommended width for the stairs going up there. For now that will be my only access point, not to say I wouldn't build an elevator or get a small forklift in the future.

I believe its at like 3'8" now (based off what a normal house stairway is), not sure if that's with or without the railings.

I'm thinking 4' minimum between the railings would be good?