Here’s the defining clause in a Level 5 Drywall Finish as described in ASTM C840’s Standard Specification for Application and Finishing of Gypsum Board: And although Level 5 consistently provides better results than Level 4, unfortunately it’s no guarantee of a perfect finish. So now, we specify a Level 5 Drywall Finish to guarantee an acceptable surface in areas of critical lighting or where a glossier finish is required. And regulations have moved the industry to virtually eliminate alkyds for interior walls, replacing them with multiple coats of latex at a higher cost and lower volume solids, which means less material is deposited to smooth out the surface. That enamel undercoat could then be topcoated with an eggshell or semigloss alkyd, especially on walls subject to abrasion, marking, or wet areas (bathrooms, showers, janitor closets) - and there was no discussion of texture imperfections telegraphing through the surface.įlash forward to today: alkyd undercoat enamels are, in our experience, virtually never specified for new construction products, and a sandable, inexpensive, VOC-compliant replacement does not appear to exist. It was inexpensive and offered the additional benefit of being sandable, versus the latex intermediates we use today that don’t buff down like an alkyd can. This enamel undercoat was thick enough to mask fine surface irregularities and fill the paper texture. Here’s a history lesson: not so very long ago, walls finished with an ASTM Level 4 Drywall Finish could be finished with one coat of latex sealer followed by a very different intermediate than we commonly use today namely, an enamel (alkyd) undercoat such as the products approved under MPI #46. It depends on a variety of factors - including whether or not you ask a painter or a drywall finisher. Question: can an ASTM Level 5 Drywall Finish produce a satisfactory painted finish in critical lighting areas and/or when using higher sheen paints? Based on the experience of Paint Quality Assurance inspector Dave Lick
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