Installing Trusses Over Flat Roof

A professional roofer will use exact measurements from the home s construction along with framing and truss dimensions to calculate the type of roof over will work best.

Installing trusses over flat roof. Once in place the workers nail the truss to the wall. If you want to build a flat roof then you will need to build a flat roof truss. A flat roof truss is also known simply as a flat truss and is not completely flat but rather slightly sloped in order to allow water to run off of the roof. Homes with flat roofs of bowstring trusses pose a problem because they are not strong enough to withstand the weight of a new roof.

How to install trusses on a roof. Installing the new roof to provide a framework for the new trusses nail 2 by 6 inch strips of wood around the perimeter of the roof. Workers manually move the first truss to the end of the roof and stand it up positioning it on the corresponding number on the wall plate. Or if you want to raise the roof a bit more install fascia around the roof perimeter attached to the new soffit and nail the new roof deck to crown molding above the fascia.

Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option a properly installed layover roof can look and function as well. This four foot truss spacing allows for 2 4 roof purlins to be placed flat on top of the trusses. These purlins are attached by driving nails through the wide face of the purlin into the tops of the trusses. After constructing your trusses now you have to get them safely to the top portion for installation.