Rooftop Generator
Rooftop Generator
(OP)
Have a steel skid mounted 500# rooftop 25 KV generator that needs to set on a 3" concrete isolation slab (roughly 3' X 6") on a 1/4 in 12 sloping roof.
I have done a lot of AC units on the roof, but never a generator with a concrete isolation slab there. Floor, yes, roof no.
Other than any extra structure below the roof sheathing, what is the normal method of installation in a high seismic area considering the slab and new roof penetrations?
I have done a lot of AC units on the roof, but never a generator with a concrete isolation slab there. Floor, yes, roof no.
Other than any extra structure below the roof sheathing, what is the normal method of installation in a high seismic area considering the slab and new roof penetrations?
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask






RE: Rooftop Generator
BA
RE: Rooftop Generator
Minimum slope for drainage, yes. But still a slope if the generator has to be flat. That can be taken up in the slab pour.
I am concerned with the detailing - sealing and anchorage - of the concrete slab to the waterproof roof membrane structure and what is normal. I do not want to reinvent the wheel here.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Rooftop Generator
I havne't done this detail, but would think you would want to go down to the roof deck and repair the roofing around the concrete. So, if concrete needs to be 3" above roofing, the concrete pad will be thicker than 3".
The deck corrugation and concrete interface will resist shear and if worried about uplift, you can tack weld a few headed studs to the supports to tie the concrete down. Not sure what your seismic factors are, but lateral load can't be much on a 500 pound unit.
RE: Rooftop Generator
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Rooftop Generator
Vibration isolators are commonly used under generator skids on yachts and oil rigs.
Mike Halloran
Pembroke Pines, FL, USA