Strongback Roof Framing

A typical peaked roof frame consists of two rafters with a cross tie to keep the tops of the walls from spreading.

Strongback roof framing.

I d be expecting the joists to frame into the beam. Intervals one run for a 20 ft. There was no sagging so there was no comment in the inspection report. A strongback is a replacement for sheathing.

Such methods use a 4 foot design module which governs a 16 inch spacing of joists studs rafters and panel sheathing products. The 2x6 serves the same purpose as bridging in a standard floor distributing concentrated loads over a wider area. It serves to make the floor more comfortable for those living and working in a structure. For more information on bracing parallel chord trusses see sbca s bcsi b7 summary sheet.

Modern building codes call for strongbacks to be of equal or greater. If not then you may want to consider tying the brace off with a diagonal brace much like lateral bracing is tied off with diagonal bracing to provide triangulation of the system. The strongbacks should be restrained to solid framing whenever possible. Purlin systems have been built in many ways some better than others.

Underneath 2x6 strongbacks laid on edge should run continuously through the webs of all the trusses at 10 ft. In my opinion the weight of the beam would actually make things worse. The idea is to provide additional support at points in which the failure of the main support network would lead to the collapse of the structure as a whole. But the rafters must resist bending flexion where they are relatively weaker.

Also sometimes known as a strong back a strongback is a type of construction that helps to enhance the strength of some type of structure by adding a secondary support at a key point in the design. Strongback bridging is an excellent and inexpensive way to improve the overall rigidity of the floor system and eliminate vibration. Truss two runs for longer trusses. Use of cripple stud to receive head sill tracks at the jamb studs helps maintain alignment of finishes.

Using a wider flange and thicker jamb stud material reduces cost of installation compared to built up jamb studs. The first approach to achieving a strong durable struc ture involving economical use of materials is to follow a basic modular plan for layout and attachment of framing members. The cross tie exerts its strength in tension so it can be made of smaller size lumber such as a two by four. Strongback infill stud advantages.

It aligns the unbraced joist edges. Back to back or boxed header.