Finish TradesQuestion 406 of 700

Before applying finish paint to new interior gypsum board, which step is MOST important for a uniform finished appearance?

a.Applying two topcoats without any primer
b.Applying a primer or sealer to equalize porosity between paper and joint compound
c.Sanding the entire wall down to the gypsum core
d.Thinning the topcoat with water by half

Explanation

A primer or drywall sealer equalizes the different absorption rates of the paper facing and the joint compound so the topcoat looks uniform and joints do not flash. Skipping primer causes uneven sheen, sanding to the core damages the board, and heavily thinning the topcoat ruins coverage.

Practice all 700 questions free — no signup required.

Related questions on this topic

Last reviewed: · editorial process

PrepPass Editorial Team · Verified against California CSLB General Building (B) Trade Examination · How we review
Report