Steel Porch/Deck Framing System
Steel Porch/Deck Framing System
(OP)
Hey everyone,
I have a project where an exterior porch is being added to an existing building. The porch wil be framed with conventional steel beams and columns. I originally designed it as a compsite slab - the spans are not large but I like the studs for getting my lateral loads into the LFRS and for vibration issues. I'm going to spec a heavier galvinization on the metal deck - and also consider it sacrificial (belt+suspenders?).
The client has requested we use metel deck with ridid insulation and a paver system on pedeastals instead of the composite system. I see how this would be cheaper but I'm concerned about redundancy. Once the deck deteriorates there is no "back-up" graity system with metal deck only.
Anyone think I'm being overly conservative here or are these reasonable concerns? Just seeing if there may some alternative I haven't thought of.
Thanks!
I have a project where an exterior porch is being added to an existing building. The porch wil be framed with conventional steel beams and columns. I originally designed it as a compsite slab - the spans are not large but I like the studs for getting my lateral loads into the LFRS and for vibration issues. I'm going to spec a heavier galvinization on the metal deck - and also consider it sacrificial (belt+suspenders?).
The client has requested we use metel deck with ridid insulation and a paver system on pedeastals instead of the composite system. I see how this would be cheaper but I'm concerned about redundancy. Once the deck deteriorates there is no "back-up" graity system with metal deck only.
Anyone think I'm being overly conservative here or are these reasonable concerns? Just seeing if there may some alternative I haven't thought of.
Thanks!






RE: Steel Porch/Deck Framing System
RE: Steel Porch/Deck Framing System
RE: Steel Porch/Deck Framing System
XR250 - That's another option. I've thought about proposing a wood system on steel framing. I'd have PT nailer plates on top of the beam and decking on top of that - or really I could just use steel for the main frames and hang wood joists off of the PT nailers. My concern is the drainage issue. As of now we have to collect and treat all runoff on the the site. But maybe we can get a pass since it would be a small area on the site.
RE: Steel Porch/Deck Framing System
If you don't want to consider the deck attachment, have you thought of plan bracing?
We work in industrial/manufacturing facilities where 90% of the time we use grating (definitely not a diaphragm) for floors. We use angles or WTs (depending on forces) as plan bracing, typically 3" below T/STL to transfer the forces.
RE: Steel Porch/Deck Framing System
Why doesn't that work for you? The metal deck provides some level of diaphragm rigidity. The insulation-paver system has been used extensively for years.
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RE: Steel Porch/Deck Framing System
JAE - I have no issues with the insulation paver system per se. it's just that the structure (including the deck) will be exposed to waether. I've never used a pedestal system where the deck would be exposed. MY concern is what happens over time as the deck deteriorates? This would be a long term issues but worth considering on the front end.
RE: Steel Porch/Deck Framing System
Considering you're concerned about deck rusting out and loosing the diaphragm, shouldn't you be more concerned abut not having the concrete for gravity loading if deck is to deteriorate? What is to transfer the gravity load from pedestals to the framing, surely rigid insulation won't cut it....
Maybe a 'belts and suspenders' method is in order like slab on deck with some horiz bracing to substitute for diaphragm if it rusts away....
RE: Steel Porch/Deck Framing System
RE: Steel Porch/Deck Framing System
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