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I am in the process of adding a pitched roof to 25′ x 100′ 100 year old masonry building with a flat roof. I had planed on using conventional 2×4 wood trusses with metal plate connectors spaced every 2 feet and 5/8 plywood. The roof is to be covered with metal sheet roofing.
I’ve recently seen a number of commercial buildings going up in my area (northern Illinois) using trusses constructed of light gage metal.
Does anyone have any experience with these trusses?
I suppose I’m curious about various pros and cons. One obvious pro would be their inherent noncombustibility, though I can’t see them holding out too long before buckling under the heat of a fire. Any comments would be appreciated
The Wood Doc
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The engineering standard is the same. Decisions are based on cost. Include the cost of learning to do steel framing.
*Advantages of steel are that the trusses will be straighter, no knots or wane, and (as you said) they aren't combustible. They definitely aren't "fireproof", but at least will not contribute more fuel to a fire. The disadvantages are that they're pretty danged expensive to buy and install. Lead times tend to be quite a bit longer. You need special clips to hang gutters and subfascia on them, which often don't get included in the initial estimates. My first reaction would be to say that it's a fairly small building, and no one will want to mess with metal trusses for it anyway. Have you checked to see who might be building them up there? Last I knew, no one in the Chicago area built them. But that certainly could have changed. I'd be interested in hearing who's doing it, if you find out.
*Ron,I'll start stopping at sites that are putting up the metal trusses. I've seen quite a few of them, though they tend to be shopping mall type buildings.
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I am in the process of adding a pitched roof to 25' x 100' 100 year old masonry building with a flat roof. I had planed on using conventional 2x4 wood trusses with metal plate connectors spaced every 2 feet and 5/8 plywood. The roof is to be covered with metal sheet roofing.
I've recently seen a number of commercial buildings going up in my area (northern Illinois) using trusses constructed of light gage metal.
Does anyone have any experience with these trusses?
I suppose I'm curious about various pros and cons. One obvious pro would be their inherent noncombustibility, though I can't see them holding out too long before buckling under the heat of a fire. Any comments would be appreciated
The Wood Doc