CSLB C-33 Painting & DecoratingSurface PreparationMedium
A painting contractor is preparing an interior wall that has extensive wallpaper residue and some adhesive still present after removal. What is the most effective next step before priming and painting to ensure a smooth, durable finish?
- AApply a coat of oil-based primer directly over the residue.
- BSkim coat the entire wall with joint compound.
- CSand the wall aggressively with coarse-grit sandpaper.
- DWash the wall thoroughly with a wallpaper adhesive remover solution.
Show answer & explanationAnswer & explanation
Correct answer: D. Wash the wall thoroughly with a wallpaper adhesive remover solution.
Wallpaper adhesive residue must be completely removed before priming and painting. Washing the wall with a wallpaper adhesive remover solution dissolves and loosens the remaining glue, allowing it to be wiped clean. Failing to remove it can lead to primer/paint adhesion failure, bubbling, or an uneven finish.
Why the other options are wrong
- A. Applying primer over adhesive residue will likely lead to adhesion problems, bubbling, or an uneven finish.
- B. Skim coating is a valid step for smoothing, but only after all adhesive residue has been completely removed.
- C. Aggressive sanding can damage the drywall paper and is not the primary or most effective method for removing sticky adhesive residue.
Wallpaper Adhesive Removal
The essential process of completely eliminating all residual wallpaper adhesive from a wall surface before painting or re-wallpapering.
- Crucial for proper paint adhesion.
- Adhesive removers or warm water/vinegar solutions are common.
- Failure to remove leads to bubbling, peeling, or uneven finish.
Memory trick: Glue gone, then prime, or your paint will moan.