C33 Wallcovering Installation and Preparation 3

Question 1

Under California building codes, what fire-rating requirement applies to wallcovering installed in commercial occupancy corridors?

Accepted Answer

Wallcovering must meet a Class A (Class I) flame-spread rating per ASTM E84

Answer

California requires Class A (flame-spread index 0–25 per ASTM E84) for wall finishes in commercial corridors to limit fire spread.

Question 2

When a wallcovering strip develops a bubble after installation, what is the correct repair method for a small bubble?

Accepted Answer

Inject adhesive under the bubble with a syringe, press flat, and roll the seam

Answer

Injecting adhesive under the bubble and rolling it flat re-bonds the material without damaging the surrounding installation.

Question 3

What does the term 'selvage edge' refer to in wallcovering?

Accepted Answer

The factory-finished, untrimmed edge of the wallcovering roll that must be removed before hanging

Answer

The selvage edge is an unprinted factory edge that must be trimmed off before hanging to ensure clean, tight seams.

Question 4

Which tool is used to firmly smooth out air bubbles and ensure full adhesion when hanging vinyl wallcovering?

Accepted Answer

Plastic smoothing brush or broad knife

Answer

A plastic smoothing brush or broad knife pushes air out from the center toward the edges without scratching or stretching the vinyl surface.

Question 5

When calculating how many double rolls (bolts) of wallcovering are needed for a room, what measurement is typically used to account for doors and windows?

Accepted Answer

Subtract one single roll for every two standard-sized openings

Answer

A common industry rule is to subtract one single roll of coverage for every two standard doors or windows to account for the saved material.

C33 - C-33 California Painting Contractor License Practice Test

C33 - C-33 California Painting Contractor License Practice Test

C33 Wallcovering Installation and Preparation 3