Truss Construction and Installation
A truss is a framed or jointed structure. It is designed so that when a load is applied at any intersection, the stress on any member is in the direction of its length. Even though some trusses look nearly identical, there is some variation in the interior (web) pattern.
Each web pattern distributes weight and stress a little differently, so different web patterns are used to deal with different loads and spans.
Trusses are stored or carried on trucks either lying on their sides or upright in cradles, protected from water.
Before you can install the trusses, there are a few things that need to be done.
• Make sure all the walls are plumb, straight, and the braces are in place on all the walls.
• Make sure that the layout is on the top of the wall for the trusses.
• Build a catwalk through the middle of the house so you have a walkway all the way down the middle of the house; this makes installing trusses a lot easier, and safer.
It also allows you to bulk set the trusses with a crane, and then stand the trusses by hand (thus, saving you more money). If you have normal trusses that need the tails cut, then do that while they are still on the ground.
• Cut the tails an inch and one-half shorter so when you add the subfascia, the measurement will be right.
• Slide a framing square out on the bottom board of the truss until the number that you are looking for comes up. Pivot the square until it is parallel with bottom of the truss. Make your line on the truss tail.
• Make sure the truss plans are available for periodic checks; this will ensure you are setting the trusses in the right place.
• When you bulk set the trusses, have them spread out over the whole length of the house in groups of 3 or 4, and lay them back in the same direction.
Lay the gable-end trusses on top, at the ends, so they can be stood first, with the sheets on, if you choose.
Brace both the sides in this manner if you have to leave it for a while. You already know how much they cost, so you do not want them blowing down and breaking.