Roof Framing 3 inch Deck, Beams at 10ft spacing

[Boiler106]

I'm curious if anyone uses this framing system in the US where beams are spaced at 10ft oc with 3N metal roof deck and how it affects utility supports.

I have two applications for this system and im concerned that it will become a problem once MEP starts going in and they are used to having supports (beams/joists) at 6ft oc.

The first is a medical office building with typical doctors offices and the other is a small scale pharmaceutical production facility.

 

[LuK13]

I used to work in fire protection. Never had framing spaced that far apart, but I can try to extrapolate from what I know.

There are hangers that can be installed in a metal deck. I imagine this would be fine to support some smaller diameter pipe, like 1" arm overs, but are you going to have enough capacity in the deck for all MEPs?

Steel pipe comes in 21' sticks, but a stick of 6" can be difficult or impossible for a fitter to handle. It can also end up maxing out a scissor lift making installation with high ceilings complicated. We would cut larger diameters into at least two 10'6" pieces to make them easier to handle. At 10'6" with some careful planning you could make sure that each piece has 1 beam line to get a hanger on, but this leaves you no flexibility for coordination. What if that 6" main needs to make a horizontal run half way between beam lines to avoid something? You or the trades are going to end up having to provide some secondary steel to support off of to solve coordination conflicts.

If you can get some trades involved early I would do a true cost-benefit analysis. The extra time and money spent sorting out MEP coordination might make any cost savings on the framing not worth it.

 

[EZBuilding]

I believe this framing system became popular a couple years back when lead times and costs for open web steel joists increased significantly.

I have not worked on a project with this type of framing, but I would expect that supplemental support for miscellaneous MEP equipment would get nominally bigger to account for the difference in span - although lots of those members tend to be oversized to have sufficient member sizes for connections. For heavier/bigger equipment, I tend to have individual framing for those elements anyways.

 

[KootK]

I believe this framing system became popular a couple years back when lead times and costs for open web steel joists increased significantly.

That's precisely how it came about for a bunch of work that I as involved with in the midwest. Then folks seemed to develop a taste for it. Clean plenums and good vibration performance for the occupancies where that matters. I didn't encounter any issues with accommodating services.

The first is a medical office building with typical doctors offices and the other is a small scale pharmaceutical production facility.

These actually sound like good fits for this system in my opinion.

 

[phamENG]

I walked into a 7-11 today (convenience store for those not familiar), looked up, and saw this system. First time I've seen it around here, which is why I hadn't posted about it. It was a new one - built in the last year - so it follows with some of the comments above.

 

[XR250]

convenience store for those not familiar

"7th Heaven" is what we used to call it after a night of drinking - sitting on the curb eating burritos smothered in Texas Pete.

 

[driftLimiter]

They make connectors to directly anchor into the deck, obviously its limited to a fairly small load. Check out [URL unfurl="true"]https://vercodeck.com/wp-content/uploads/2021/04/Roof_Deck_Design_Guide_V2021.pdf[/url]

They cover the limitations of this pretty well. You can get away with sprinklers and other light elements hanging from the deck itself. Supplementary framing for heavier equipment.