- Code table
- C402.1.3, Zone 1
- Attic and other
- R-38
- Above-deck roof
- Not this service
- Return plenum
- We do not blow into it
The commercial number is not the house number
Houses in Palm Beach County and Broward County are Climate Zone 1A. The residential ceiling minimum is R-30, and our house standard is R-38. A commercial building in the same county uses a different table.
Table C402.1.3 of the 2023 Florida Building Code, Energy Conservation, Zone 1, lists attic and other roofs at R-38. That row is the same for Group R, such as an apartment building, and for other occupancies, such as an office or a store. R-38 is the prescriptive target for a commercial attic. It is not a sales upgrade.
A low-slope roof with insulation entirely above the deck is a different row: R-20 continuous for most occupancies, R-25 continuous for Group R. That is a roofing assembly. We do not install it. A metal building with a liner system is R-19 plus R-11 LS in Zone 1. A loose blow is not that system either.
Where the blow goes
The fill goes on the thermal boundary. On a building with a real attic over a hard lid, that is the attic floor, the same as a house. Open-web joists get the same treatment if the ceiling below is the boundary and the space above is vented or open to an attic.
Depth is checked against markers. The commercial energy code calls for blown ceiling insulation to be marked in inches, at least one marker for every 300 square feet, facing the access. You should be able to read the depth without crawling the whole building.
Fiberglass or cellulose follows the same installed R-values we use on houses: about R-2.5 per inch for new fiberglass, about R-3.6 per inch for new cellulose. From a bare lid, R-38 is about 15 inches of fiberglass or about 10.5 inches of cellulose. Existing dry fill counts, at the settled R-value, and only the gap gets blown.
A return-air plenum is not an attic
A lot of commercial ceilings are the return path for the air conditioner. The space above the tiles is a plenum, not a place to store insulation. Loose fill in that airstream gets into the unit, the coils, and the rooms.
We do not blow into an open return plenum. If the thermal boundary is a lid above that plenum, the blow goes on top of a sealed lid, out of the airstream. If there is no lid, this is not a blown-in job. Tell us which one the building is before we schedule.
Occupied buildings
Stores, offices, churches, and clinics do not empty out because an insulation crew is coming. We schedule around the occupancy. Furniture, stock, and desks under a ceiling access get covered. The hatch gets closed and cleaned at the end of the day.
Wet, moldy, or rodent-contaminated fill comes out first, at its own price. We do not blow over it because the building is open tomorrow. A roof leak is a roofer's repair. New insulation does not fix the leak, and we will not cover an active one.
What we need for a number
Ceiling area, photos of the access, and whether the space above the ceiling is an attic or a return plenum. A set of plans helps. So does knowing if people will be in the building. The house planner on this site is for a house attic. A commercial bid is priced from the building, not from that form.
The shops are still 4263 NW 1st Ave in Boca Raton and 955 S Congress Ave in Delray Beach. Call (561) 654-7698 and say it is a commercial ceiling.