Storage Units on Garage Attic Trusses

Storage Units on Garage Attic Trusses.  Many times during a home inspection I come across garages with storage units and sometimes even living areas that home owners have constructed.  There are two types of roof support systems generally in use,  the rafter system and the roof supported by engineered trusses.

The building’s roof must be designed and constructed to fulfill the following functions:  the roof must be able to transfer wind and snow loads to the house walls;  the roof must be able to shed rain and snow away from the building and prevent water from penetrating into the roof area;  the roof must be also able to provide for the removal of moisture and heat contained in the insulated roof assemblies;  and accommodate the installation of materials designed to restrict the flow of the air and moisture from the house into the roof assembly.

Engineered roof trusses are becoming more popular and are widely used in construction of new homes.  Trusses can reduce material by up to 40% and allow longer clear spans.  An engineered wood roof truss is designed to meet the Building Code requirements for support load, wind load and snow load, which is spread equally over entire roof surface.  If a roof truss is damaged during installation, the installer, must contact the manufacturer to obtain a Repair Detail from Building Designer, Truss Designer or Truss manufacturer.  Because the truss is a designed system any changes or modifications from intended use must first be approved by designer.  The picture above shows the trusses have separated and will require specific repair details to repair.



Hanging storage systems from an engineered truss system would definitely be considered a change of design as you are now creating a hanging load on a engineered system which was designed for a support load for the roof, ice, snow and water.  The problems with attaching storage units to existing truss roofing systems is that it will not meet any requirements of the building code,  you did not get a building permit to perform the work and if truss system failed you could be held liable for any damage or injury.  Also if you are selling your home this problem will be noted on home inspection report, which could affect sale or price of your home.

Renovating parts of your home without obtaining a building permit may seem like a good idea at the time but the money saved can quickly seem insignificant to problems encountered by not being code compliant.  No good contractor will perform work without obtaining all the required permits and you should be hesitant to use a contractor will to do work on your home without a permit.  You only have to watch Mike Homes inspection programs to see the pitfalls of using contractors that are willing to take shortcuts during your home’s renovation.