Insulation and Radiant Barrier Certification
Specifying the right R-value is not enough. All insulation must be certified by the state for its conductive thermal performance, and a radiant barrier must have an emittance of 0.05 or less and its own certification.
Certification, not just performance
All insulation must be certified by the Department of Consumer Affairs, Bureau of Household Goods and Services, confirming that its conductive thermal performance is approved under the state's Standards for Insulating Material.
This is a different kind of requirement from the R-values in the envelope sections. Those say how much insulation a wall needs; this says the product has to be one whose performance has been independently established. A material with a claimed R-value and no certification cannot be used to comply, however good the claim.
Radiant barriers: 0.05 emittance
A radiant barrier must have an emittance of 0.05 or less, tested to ASTM C1371 or ASTM E408, and must be certified under the same Standards for Insulating Material.
Emittance rather than R-value is the right measure because a radiant barrier does not work by resisting conduction — it works by refusing to re-radiate heat. An 0.05 emittance means the surface radiates almost nothing, which is why a shiny foil performs a job that inches of batt cannot.
Urea formaldehyde foam has a specific condition
Urea formaldehyde foam insulation may be applied or installed only where a 4-mil-thick polyethylene vapor retarder, or an equivalent plastic sheathing vapor retarder, is installed between the foam and the interior space — in all applications.
"All applications" leaves no room for a judgement call about whether a particular assembly needs it. The requirement exists because of what the material can release into occupied space, so the barrier is not negotiable by climate zone or assembly type.
Flame spread and smoke density
All insulating material must be installed in compliance with the flame spread rating and smoke density requirements of the California Building Code.
That is a Building Code requirement appearing inside the Energy Code, and it is worth noticing because it means an insulation decision made purely on thermal grounds can fail on a fire criterion. Exposed insulation in a plenum or an attic is the usual place this bites.
Liquid applied roof coatings
Roof coatings have their own minimum performance table. This matters on re-roofing work, where a recoat is inside the alteration requirements — the coating has to be a product that meets the stated performance, not simply a reflective paint.
What this means in practice
Check certification, not just specification. The difference shows up at submittal review: a product data sheet quoting an R-value is not the same as evidence the product is certified, and substitutions made on site for availability are where uncertified material enters a job.