Platform support for flat roof

[TS59401]

Hello,
I have a client that is wanting a small (12'x9') roof mounted aluminum platform to facilitate stack testing a couple times a year. In that past they have been using scaffolding to access the stack ports. The roof is structural steel supporting metal decking, supporting sloped insulation with a membrane cover (design roof live load = 30psf). I am attempting to locate a type of "foot" that I can use to land my square tubing platform columns on the roof, and some tie down details to anchor the structure. There are no real uplift forces, I just don't like the idea of it floating around up there.

I cannot be the first to need something similar, does anyone have any suggestions? A link to something similar: Link

Thanks,
Tom

 

[dik]

If permanent, in these environs, the biggest issue is the snow accumulation caused by the platform obstruction.

Dik

 

[TS59401]

Thank you dik. We have considered the snow load and feel comfortable with the framing.

I see from the lack of response that our best option may be to penetrate the roof membrane (round tube in order to use a standard seal boot) and land on either existing or newly placed framing members. Any lessons learned or advice for this type of support?

Thanks,
Tom

 

[dik]

You have to and I use fabreeka (sp?) thermal isolators to minimise thermal transfer and angles to support interrupted deck. They have good bearing capacity. Often encounter snow accumulation around equipment and platforms.

Dik

 

[jayrod12]

How tall? I've previously convinced cost-conscious clients into having a portable aluminum platform that is on large air filled rubber wheels and can be rolled around as required. When they reach the location they want to use it, they put 18" square pieces of plywood underneath the wheels to protect the roof membrane and insulation.

To them, this was a cheaper and easier thing to accommodate. And it provided them access as required to facilitate service/testing on their mechanical equipment.

 

[TS59401]

Dik - I like the look of those thermal breaks. I wonder if they would give me two fold benefit with galvanic corrosion as well.

Jayrod12 - This structure is only 6ft above the roof. My gut tells me that square pads would work because that exactly what the scaffolding they were using for years bears on. I am reluctant to sign off on it for my replacement platform due to a total lack of information on the rigid insulation.

 

[dik]

Used the Fabreeka pads lots of time... often for cable tray supports to side of building. They have a fairly high compressive stress. Used to use HDPE prior to them with a much lower compressive strength. They are an electrical insulator, so, shouldn't hurt...

Dik