Suspended Floor Passthrough

[vtjon]

As I plan my new garage, I've basically decided to put it on a basement foundation with a suspended concrete floor due to my site grade and fill requirements. The tentative plan (pending quote) is to use steel beams, metal decking and poured slab on top. The basement will be mostly used for storage but would also like to put my air compressor there. The garage itself will have a new 200 amp service.

My question is how do I "rough-in" for getting things between the floors? I will need to run my air lines and electrical wiring through the floor for the compressor, lights and any future needs. Should I consider putting a sub-panel in the basement? I'm guessing that would be overkill.

I saw one build where they formed an 8" hole through the floor. How does that work with the metal decking?

 

[TRWham]

Cast pipe sleeves into the slab and cut them off flush after the slab is poured. The sleeves run through holes in the deck and need to be tight. You can even weld them to the deck, but I'm not really sure that's necessary. as long as they are tight enough to hold the concrete while it cures.

I doubt you need a sub-panel down there, but you will need a disconnect for the compressor.

 

[GMCGarage]

Cast pipe sleeves into the slab and cut them off flush after the slab is poured. The sleeves run through holes in the deck and need to be tight. You can even weld them to the deck, but I'm not really sure that's necessary. as long as they are tight enough to hold the concrete while it cures.

I doubt you need a sub-panel down there, but you will need a disconnect for the compressor.

Plan for box outs where you think you will need access. Any other small things that pop up just core drill holes.

You could put in a bank of conduit (5-10 pieces near your box that you could add to later. These would be flush and you could riser them and cap until needed.

 

[Innovate1]

If there is a hollow core precast concrete plant near you then you could consider placing them instead of the steel decking and just pour a slab over them. I did a small section that way 15 years ago and it wasn't too costly. I priced recently and the cost was surprisingly high. I suspect it depends a lot on locality.

 

[ConCretin]

Cut a few holes in the metal deck and run a short piece of PVC pipe through them before the pour. A riser clamp works great to hold the PVC sleeve in position.

 

[vtjon]

I've been running the hollow core rabbit down for two weeks. I don't have anywhere within 200 miles of me and the initial quotes I've gotten have been expensive ($14k) plus I'd have to hire a local crane and crew to set and grout them. This is getting close-ish to a suspended floor "system" though but I might have to get engineering involved on the hollow core planks here.

This will be a stick built structure that will sit on a stem wall that is 12" or so above the suspended slab. If I do a box out or a PVC pipe through the deck/slab, I would have to get my wire out of the wall and down through my PVC. If I get my PVC close enough to the foundation wall, it should be pretty seamless though not hidden.

Thanks for the advice.

 

[larry4406]

Concur on the PVC pipe thru the deck.

On a similar thread recently, someone mentioned Spancrete. I found this video which is neat. Not sure the costs though but it eliminates the steel and metal decking. However they parge/cement the panels together which makes for an ugly finished floor. Not sure if one them pours a topping slab or epoxies it.

 

[Stuart in MN]

Cut a few holes in the metal deck and run a short piece of PVC pipe through them before the pour. A riser clamp works great to hold the PVC sleeve in position.

Do you need to caulk around the hole before the pour? I suppose it depends on how well the pipe fits in the hole, but I can also imagine wet concrete leaking out.

 

[flat350]

Sleeve anything you need with PVC or steel,cut a hole through the deck and secure it with a friction/riser clamp above(available at any plumbing wholesaler)if your hole is rough hit it with a little spray foam to seal it.

It's done all the time in new construction with poured decks,Hilti even makes a sleeve that is fire rated for use on metal or wood decks with concrete poured on it.
https://www.hilti.com/c/CLS_FIRESTO...EVICES_ACC_7131/CLS_CASTIN_DEVICES_7131/r3622