Lower Cost, Easier Installations
One of the reasons that sprinkler systems have become so cost-effective for homes is that now plastic pipe can be used. CPVC (chloro-polyvinyl chloride) is the lightweight material used for plastic piping. Special glue secures the CPVC pipe connections, reducing the problems of sweating copper joints or threading steel pipe.
Either plastic or copper pipe is typically used in unfinished basements. CPVC pipes are fed off a riser passing through the interior wall space to the upper floors.
NFPA 13D does not require sprinklers in unfinished attics. In regions where freezing is a concern, pipes are installed in the walls instead. In finished attics and in warm regions, pipe can be run up into the attic and ceiling sprinklers can be used.
See a typical sprinkler water supply
See some of the new fire sprinkler designs