Replies

1. 
   BobKovacs | Nov 09, 2005 06:35pm | #1

   Metal decking with 5" of concrete fill?   If they're really fire-conscious, you could always add an inch or so of spray-on fireproofing  ;)

   Seriously, how about a layer of 5/8" Type "X" drywall, with the plywood over the top?  That'll give you one-hour, though the framing won't be protected if it's under the drywall.

   Bob

2. 
   xxPaulCPxx | Nov 09, 2005 08:27pm | #2

   There is also Hardipanel in 4'x8'x5/16" sheets, it's smooth surface and thinner than drywall with better fire capabilities.  Mabey a sheet of 1/2" underneith to keep from breaking though if used as a floor.

   Rebuilding my home in Cypress, CA

   Also a CRX fanatic!

3. 
   doodabug | Nov 10, 2005 02:51am | #3

   How about fire code rock under and fire treated ply on top?

1. 
   McMarky | Nov 10, 2005 03:28am | #4

   I was also going to mention Fire Treated ply.  How about metal pan-decking, with either FT ply, concrete, or gyp-crete on top of the pan?  Spendy though.

   Edited 11/9/2005 10:17 pm ET by McMark

4. 
   firedude | Nov 10, 2005 03:43am | #5

   no such thing as "fireproof" except for masonry construction - and even that will fail if the fire's hot enough - most of the problems are contents or interior finish materials - UL has specs for fire-rated assemblies, usually one or two hour assemblies - most call for 5/8th fire rated drywall on both sides of the framing with specific fastening schedules - other assemblies for floor/ceilings use - 3/4 plywood will gave a fair amount of protection - one important thing would be to seal any penetrations so the fire would be contained in the source area and not spread

   what is your client's concern - what's the fire "source" and load? hard wired interconnect smoke detectors will provide early warning throughout the house if there's a fire in the attic

   quick thoughts

5. 
   Piffin | Nov 10, 2005 05:22am | #6

   No such animal in this situation. You already have steel joists which in afire will fold up and fail before wood joists will.

   of course flame spread is going to be slower but fireproofing ain't gonna be happening

    

    

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6. 
   experienced | Nov 10, 2005 07:40am | #7

   Not fireproof but it gives plywood/OSB a 30 minute rating. It's from a company called International Barrier Technology-

   Blazeguard¯ fire rated wood panels consist of a sheet of oriented strand board (OSB) or plywood combined with a thin coating of International Barrier's patented Pyrotite fire resistant formulation.

   • A Blazeguard wood panel is able to achieve a Class A, structural flame spread rating (as measured by ASTM E-84 extended to 30 minutes) and its burn-through resistance (as measured by ASTM E-119) is nearly triple that of untreated wood panels.
   • Blazeguard¯ has been evaluated by code evaluation services agencies for use as structural roof sheathing, exterior fire resistant wall assemblies, interior panels, as a thermal barrier for structural insulated panels (SIPs), and as a component of floor decking.
   • Blazeguard wood panels are stronger than uncoated wood panels, and do not lose strength over time. In contrast, pressure-impregnated, chemically treated fire retardant treated (FRT) plywood loses strength during the treatment process and thereafter.
   • Blazeguard is resistant to periodic wetting, so rainstorms on the job site do not require "redrying," as does FRT plywood.
   • Blazeguard waste (from board trimmings) is environmentally friendly and safe for any landfill that would normally accept plywood or OSB waste.
   • Blazeguard is easy to handle and install, and is impact resistant.

   Blazeguard¯ is used in building applications where either a Class A flame spread or burn through resistance rating is required by building code, or where developers/builders generally desire a high quality, environmentally friendly, non-toxic product that delivers superior fire resistance and attributes such as mold and mildew resistance, structural strength and impact resistance. Insurance rates may be reduced if the fire safety of a building is enhanced by materials like Blazeguard.

7. 
   BillBrennen | Nov 10, 2005 08:42am | #8

   Cloud,

   Is this new construction? Does the owner want to protect against his stuff stored in the attic catching fire and taking the house with it?

   The paint companies sell a special intumescent latex paint that can be used to coat all sides of the floor system before it is covered up with drywall. (Assumes new construction.) In a fire, the paint swells into a refractory foam that insulates what it is covering against the heat. It could act like fireproofing lite on your bar joists, too.

   The special paint will not hold up to traffic very well, so you could give him a price to cover the walksurface with diamond lath and latex cement, 1/4" thick.

   An interconnected smoke alarm up there is a good idea, too.

   Bill

1. 
   CloudHidden | Nov 10, 2005 09:06pm | #12

   >Is this new construction? Does the owner want to protect against his stuff stored in the attic catching fire and taking the house with it?New construction. "No" on the second question. Just wants to choose as many non-combustible materials as possible. Yes, steel will do unpleasant stuff when hot, but his goal would be to not let it get to that point. If no wood, then no combustion, then no melted metal. Most interior walls are shotcrete sandwiches. Wants to not add combustibles where avoidable.

8. 
   rjw | Nov 10, 2005 04:50pm | #9

   >> framed in steel, only need subfloor w/ no finished flooring. Client is ultra fire conscious.

   Is steel the material of choice for the ultra fire conscious?

   I have heard (don't know for sure) that steel is generally considered less protective in a fire than wood because it supposedly deforms and loses structural integrity a lot faster than wood burns to the point it loses it's structural integrtity.

   ---

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1. 
   firedude | Nov 10, 2005 07:11pm | #10

   problems with steel in fires
   - loses strength. starts to deform/"soften" at about 1000 degrees F
   -lengthens when hot -steel truss construction will push down masonry walls..... and shortens/twists when cooled - will pull in masonry wall and change the "pitch" of the roof
   -conducts heat so any combustibles in contract may ignite - big problem in wood truss with steel connection plateshowever, when properly protected (such as 5/8 firecode drywall - side note, from supplier, all 5/8s is supposedly "firecode"?) and no penetrations, is probably good for an hour or more of fire containment - should be enough time for the "boys" to get there and put it out..... if the smoke detectors or fire alarm system is workingunderstand in Oz land, they use double 5/8 each side for protection so there's 1 1/4 to burn through before the structure is affected

1. 
   rjw | Nov 10, 2005 08:43pm | #11

   Thx, good info

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