According to cal fire s solar photovoltaic installation guidelines below are illustrations of currently enforced fire setbacks pathways for residential solar system installations.
Roof ridge setback for solar panels fire department.
Roof setbacks from ridge for ventilation relaxed from 36 inches to 18 inches for solar systems that take up less than 1 3 of the plan view total roof area.
While some areas have local ordinances requiring setbacks and pathways others do not or the system may have been.
R324 6 roof access and pathways.
It also says in article 605 11 3 2 4 that panels modules installed shall be located no higher than 3 ft below the ridge to allow for fire department ventilation operations combined these codes require a 3 ft clearance down from the ridge of a pitched roof to allow for fire departments to ventilate the building.
This excess weight doesn t seem like much but it can reduce the precious time that firefighters usually have to fight the blaze before a typical roof collapses.
A typical solar panel weighs around 40 pounds so an average sized 5kw installation with 20 panels adds another 900 pounds with additional hardware to a roof.
For homes with sprinkler systems if the system takes up less than 2 3 of the plan view total roof area the setback for ridge ventilation is also relaxed to 18 inches.
3 clear width measured from the load bearing wall to the pv panel to the ridge on all sides of each roof slope where panels modules are located.
Los angeles fire department requirement no.
Any roof with pitch equal or less than 2 in 12 9 46 degrees doesn t require any setbacks pathways.
In laboratory based fire tests of roof assemblies 1 2 the maximum allowable fire spread is between approximately 20 and 40 ft 2 1 9 and 3 7 m 2 depending on whether an a b or c rating is desired.
Full text of the california residential code regarding the access and pathways for residential single and two family dwellings.
Use relaxed fire pathway codes to build bigger arrays on roofs.
200 to 400 square feet.
Roof access may be limited by solar panels of any type see photo 1 below.
The following is the los angeles fire department s.