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Securing the Roof-Truss System

Bob talks with Bill York and Rob Davis of FLASH (Federal Alliance for Safe Homes) about the construction of a storm-resistant roof system built with roof trusses. Bob reviews specifications for how to secure a wooden rootruss system to a steel structure. With the addition of steel fasteners, the building's roof will have an uplift resistance of about 850 pounds, making it capable of withstanding wind speeds of up to 140 mph. To secure the wooden structure to the steel shipping container, a steel piece or angle iron is welded to the top of the box and a threaded bolt is welded on to it. The bolt sticks through the wood, where it is secured by a nut and washer, transferring the load back to the steel box. In high winds the ends of the roof experience much greater force, so the first six feet of each end of the roof is secured by steel straps, giving the ends 1200 pounds of uplift resistance. Plywood sheathing that is 5/8-inch thick or 1 1/2 times thicker than sheathing specified by the Florida Building Code. Construction adhesives are also used to secure the sheathing, again going beyond code to make a stronger roof. Building codes require the use of eight-penny nails (2 1/2 inch nails) to secure the plywood to the roof framing, but FLASH's Blueprint for Safety specifies ten-penny nails to give 50 percent greater uplift resistance. With the use of ten-pennny nails and adhesive to secure the roof, the roof probably has twice as much uplift resistance as a roof built to code.

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Revitalizing Bartlett Park, Florida Now Playing

Revitalizing Bartlett Park, Florida

Historic Neighborhoods of St. Petersburg Now Playing

Historic Neighborhoods of St. Petersburg

Installing Impact-Resistant Windows Now Playing

Installing Impact-Resistant Windows

Securing the Roof-Truss System Now Playing

Securing the Roof-Truss System

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Bartlett Park Shipping Container Home

Clip Transcript For:

Securing the Roof-Truss System

computer-generated transcript - may not be 100% accurate

" So now let's go up on the roof and talk with our friends from flash. All right useful. You're seeing a lot of action here is all of these trusses have already been brought up into play some. And since what we have here is a steel box we need to learn how you -- and altogether we have Billy York and rob Davis and flash and just to refresh our minds what does flash stand for federal alliance for safe homes -- home. One of the main things that we're concerned about in Florida in terms of safe homes his. Keeping hurricane is from this. We're gonna just watch them for 12 while they finish -- these fasteners so that we don't have to yell above them. Be sure is putting a lot of know and well we need the nails to be able to carry the uplift resistance. These trusses will have an uplift resistance of about 850 pounds when he's finished with those Clinton -- So that means they'll be able to resist a force. Comparable to 850 pounds how does that translate into wins this house is designed to withstand the 140 mile an hour wind speeds and meet the flash blueprint for safety standards okay. Now. As -- said it Mario we're building a wooden structure on top of a steel structure yeah what's the transition out of our."

" well it's a steel on top of the box and then on top and still they've welded these five days diameter threaded bolts. And then the bolt sticks through the blood and you can see we use a nut and washer at which then holds the -- in place and allows us to transfer the load back into."

" The box sides of the steel that they've welded onto the corner is it running the whole length of this thing -- it is. And it is essentially what we might call angle iron yes it and and is there. All right and then you've got it threaded and bolted down. All right so what's the purpose of this topic type of strapping that's being put down here the clothes that are clearly. Ends of the roof are higher than they are middle -- so for the first approximately six feet of the roof we have to using heavier duty tie down strap. So this connection that putting there. It's gonna give us about 1200 pounds up. Uplift resistance versus the 850 pounds we had from the two clips that we saw earlier -- I understand that system is is at the gable end where there's more. Possibility for uplift. From the external wind. OK. OK so what kind of plywood do we recommend using what you got."

" Right here is they're installing five eighths inch plywood up on the top that's number one and a half times thicker than she regularly see required by the Florida building code. This fight -- it is normally would they grudges -- sixteenths is that right okay. And what about fastening down are they using any kind of construction adhesives. Odd looks like they are in this case and that's not required at all sunny and nice extra and it's a very nice extra OK and what what about."

" Nailing what kind of nails should you use a code requires have been eight penny nail what is who have finished nail the blueprint for safety requires a ten penny nail -- what does a larger nail and gives about 50% additional up. Resistance until -- is using the ten penny nails. And the adhesive they've probably got double the distance of more. Right that's great."

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