Each truss component is a part of a system; each truss, when installed in a house, is part of a floor or roof system. Since a truss depends on the interaction of all its members, any damaged or missing members greatly affects the overall strength of the truss. Likewise, any damaged or missing member of an assembly of trusses also affects the ability of the system to provide its intended function. One often overlooked, but critical part of a truss system, is the bracing. Trusses require temporary bracing during installation. But permanent bracing is also required to strengthen the truss system after completion of the house by preventing movement or buckling of the individual trusses.
Roof or floor sheathing serves a bracing function, but sheathing alone is not enough in most cases. It is normal to find bracing attached between trusses along the midpoint of compression web members to prevent buckling. Some truss manufacturers staple paper tags indicating bracing points as guides for installers. If you see these tags or other markings, but no braces, then bracing was omitted. Unfortunately, it is often difficult for a home inspector to know what bracing is permanent versus temporary.
For that reason, it is best to not assume any bracing is only temporary and make note of any apparent broken, loose or missing sections as a precaution. Some contractors make modifications or remove trusses to accommodate new air conditioning units installed in attics. This could compromise the integrity of the truss system.
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