Pre-constructed wood trusses are a great way to simplify construction of a commercial or residential building. But what if you need to install a sprinkler system?
The Importance of Incorporating Sprinklers
Many municipal codes require functioning sprinklers in newly constructed buildings, and the National Fire Protection Association (NFPA) strongly recommends their installation to save lives and minimize property damage when fire does break out. The NFPA has found that 96 percent of operating sprinklers were effective in meeting the goals of protecting life and property.
What's more, functioning sprinklers can often save the building owner money in reduced insurance premiums. They can also make the building's resale value higher. So including them in a building, even if they are not required by law, can be a smart move during construction.
The Need to Properly Calculate Sprinkler System Weight
But when it comes to installing a sprinkler system into pre-made wood trusses, there can be some challenges. The main issue comes from the added weight of the system's pipes and fixtures, which may require a re-calculation of what load the truss can support.
Why is this important? After all, most wood trusses should easily be able to support the additional weight of a few pipes, right? While the trusses may be able to support the sprinkler pipes with no problem, building codes require that the weight be incorporated into calculations and supports be considered so that buildings are ready for earthquakes.
To do this, the dead load, or added weight, of the sprinkler system has to be determined first. The building designer or structural engineer involved with the construction also has to figure out the locations for where the sprinkler pipes should be attached. The trusses may need to be reinforced or a different style of truss must be used in order to support the additional weight of water-filled pipes at the attachment point.
Finally, an additional weight of 250 pounds per attachment is often required by code or NFPA guideline -- this is included to cover any accommodations that the system installers need on a short-term basis while the pipes are being installed.
Fortunately, most manufacturers of wood trusses have already incorporated these additional weights and calculations when designing and constructing the finished product. In fact, many types of trusses are available that already have incorporated ways to attach and brace sprinkler pipe. Usually, these supports are in place for the top chord of the truss, but if you need to attach pipe to bottom chords on your trusses, the manufacturer can make special accommodations.
For more information, contact Campbell Truss Company Inc or a similar organization.