Minimum Concrete Topping 1

[dik]

I usually spec 2-1/2" conc for treads and landings on steel stairs. This seems to be standard practice in these environs.

Part of my current work is reviewing steel construction for a metal fabricator. I've just received steel stairs with 1-1/2" concrete topping for both the landings and the treads, and I think this is too thin. Is there any reference out there that recommends a minimum thickness?

To make matters more interesting, the tread span is 50" (so it's wider than normal) so more prone to vibration from people 'bouncing' down stairs.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Enable]

The NAAMM Metal Stairs Manual does not provide recommendations per se but it does provide examples and all such examples have a 3" min concrete thickness at landings.

For what it is worth, it is typical for us in Ontario to use 3" on landings and 1.5" in the pan with WWF for 36" wide stairs (as minimum).

 

[dik]

Thanks enable... is that 3" including the 1-1/2" steel floor deck or 3" plus the 1-1/2" steel floor for a total thickness of 4-1/2"?... I've use 1-1/2" for tread in a normal stair, but typically use 2-1/2", but not for 50".

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Enable]

3" including the steel ribs

But given the width you may just want to put a call into the fabricator. Typically the pans are not self-fabricated by the stairs contractor and are ordered from a third-party supplier from a standard selection of sizes / configurations / depths. It may be no trouble at all if their supplier has deeper pans.

 

[dik]

Thanks... I've gone to the thicker topping 4" including deck thickness (also typical with composite deck 20GA; the span is less than 4' for the landing) and reinforced with WWM in flat sheets and for the treads have designed them as a 3" slab spanning 50" and put 3 - 10M bars bottom. No composite action with the metal pans... cost more to analyse it and bond would be a WAG... I'm happy again... thanks. Sealed and sent out...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik