Warehouses often run into high-piled combustible storage requirements sooner than expected. In many cases the simplest way to stay compliant is to set clear height limits and keep higher-hazard materials separated so large portions of the building never cross the high-piled threshold.
Under the California Fire Code, storage becomes high-piled combustible storage when combustibles are stored more than 12 feet high, or more than 6 feet high for high-hazard commodities. Once an area exceeds those heights and is larger than 500 square feet, a high-piled storage permit is typically required and the storage must meet Chapter 32 arrangement and protection rules.
Height limits by commodity class
Class I–IV commodities generally stay low-piled up to 12 feet. High-hazard commodities, including Group A plastics, generally stay low-piled only up to 6 feet. Holding each zone to its respective limit on the storage plan can avoid treating the entire building as high-piled storage.
One practical way to maintain these limits is to mark maximum storage heights directly on the racks. Permanent indicators (tape, painted lines, or labeled signs) at the approved height give operators and forklift drivers a clear visual stop. This reduces the chance that storage creeps upward over time and keeps the area within the low-piled classification that was approved.
Separation of Group A plastics
Mixing Group A plastics into a Class I–IV area can cause the whole area to be protected as Group A plastic storage, even if the plastics themselves are stored low. Keeping them in a dedicated zone with its own 6-foot height limit prevents that.
These controls are usually documented on a simple storage plan that shows zone boundaries, maximum storage heights, and commodity classes. When the Authority Having Jurisdiction can see the limits clearly, the review is often faster and the sprinkler system can remain on a standard design.
Height limits and commodity separation will not work for every building, but they are one of the more common ways to reduce the scope of high-piled storage requirements while still using the available storage height.
Need help with a storage plan or inspection notice?
If you received an inspection violation for high-piled storage, need a commodity classification and storage plan, or want to review height limits before submitting for a permit, contact us.