Question 1

What are the drywall finish levels?

Accepted Answer

Drywall finish is graded from Level 0 to Level 5 under the Gypsum Association's GA-214 recommendations. Level 0 is board left as installed with no tape or finishing, Level 1 has tape embedded in compound at joints and angles, and Level 2 adds a coat over the tape and is used as a tile substrate or in garages and storage areas. Level 3 adds another coat for areas that will get medium or heavy texture. Level 4 is the common smooth wall finish for flat paint or light texture, and Level 5 adds a skim coat over the entire surface.

Question 2

Which finish level do I need for painted walls?

Accepted Answer

For smooth walls with flat paint or light texture, Level 4 is the typical specification. Level 5, which adds a skim coat over the whole surface, is recommended for non-flat or glossy paints, dark or deep-tone colors, and critical lighting conditions. Choosing Level 4 under a semi-gloss or a dark color is a common reason joints and fasteners show through. Agree on the finish level in writing before the job starts.

Question 3

What is the difference between 1/2 inch and 5/8 inch drywall?

Accepted Answer

The main differences are thickness, weight and fire resistance. 5/8 inch board is commonly sold as Type X, such as USG's Firecode X panels, which comply with ASTM C1396 and provide additional fire resistance over regular panels. That makes 5/8 Type X the usual choice where a fire-rated assembly is required. 1/2 inch board is lighter and easier to handle for ordinary walls. Your local building code and any fire-rated design on the plans decide where Type X is required.

Question 4

How long does joint compound take to dry between coats?

Accepted Answer

It depends on whether you use drying-type or setting-type compound. Drying-type compound hardens as water evaporates, so its time varies with temperature, humidity and airflow. Setting-type compound hardens by chemical reaction on a known schedule; USG lists Easy Sand 45, for example, as setting in 50 to 65 minutes, which allows same-day joint finishing. USG also requires surface, water, mix and air temperatures of at least 45°F until joints are completely dry.

Question 5

What does critical lighting mean for drywall?

Accepted Answer

Critical lighting is strong side lighting, such as sun through a large window or wall wash fixtures, that skims across a wall and exaggerates every ridge and dip. Under these conditions even a good Level 4 finish can show joints and fasteners. The Gypsum Association guidance recommends Level 5 where critical lighting conditions occur. Identify these walls during estimating so the finish level and price match.

Question 6

How do I estimate how many sheets of drywall I need?

Accepted Answer

Add up the wall and ceiling area, then divide by the area of the sheet size you plan to hang. Measure each room's perimeter times wall height for walls and length times width for ceilings. Larger sheets mean fewer joints to finish, so plan sheet layout around the room's dimensions rather than total area alone. Add an allowance for waste, cutouts and damaged sheets based on your own past jobs.

Question 7

How should a drywall contractor bid a job?

Accepted Answer

Bid from the plans or a site measure, broken into hanging and finishing, with the finish level stated. Note ceiling heights, stairwells, access, board types such as Type X or moisture-resistant panels, texture, and any patching or demolition. Specify who handles cleanup, debris and priming. Pricing varies by market and job, so base your production rates on your own crews' history.

Question 8

Is drywall dust a silica hazard?

Accepted Answer

It can be, so check the safety data sheet of each joint compound and board for crystalline silica. OSHA has a respirable crystalline silica standard for construction, and employers can comply by following the control methods in Table 1 of that standard or by assessing worker exposure themselves. Whatever the SDS says, controlling dust with vacuum sanders, wet methods, ventilation and appropriate respiratory protection protects your crew and your client's home.

Question 9

Does the EPA lead rule apply to drywall work?

Accepted Answer

Yes, when the work disturbs painted surfaces in housing or child-occupied facilities built before 1978. Cutting out painted drywall or plaster, demolishing painted walls and large patch jobs can all trigger the RRP rule. Work disturbing six square feet or less of paint per room inside is exempt, but demolition of painted surfaces is always covered regardless of size. Covered work requires an EPA or state certified firm and a certified renovator.

Question 10

Could the joint compound in an older home contain asbestos?

Accepted Answer

Possibly, in older homes. The Consumer Product Safety Commission banned consumer patching compounds containing asbestos in 1977, citing the risk of inhaling fibers during mixing and sanding, so compounds from before that era may contain it. EPA advises leaving undamaged asbestos-containing material alone and having removal or major repair done by people trained and qualified to handle asbestos. If you suspect it, have the material tested before you sand or demolish.

Question 11

What drywall should be used in bathrooms?

Accepted Answer

Use moisture and mold resistant panels on bathroom walls and ceilings, and a tile backer made for wet areas inside showers and tub surrounds. Standard paper faced board is not designed for areas that get wet regularly. Requirements differ by product and jurisdiction, so follow the panel manufacturer's installation guide and your local building code.

Question 12

Why do drywall seams show through the paint?

Accepted Answer

Seams usually show because the finish level was too low for the paint or lighting, or because the surface was not primed evenly. Joint compound and the board's face paper absorb paint differently, which can make joints look duller or shinier than the field. A proper primer and, under gloss paint or critical lighting, a Level 5 skim coat reduce the problem. Ridged or crowned joints need to be corrected in the finishing, not covered with more paint.

Drywall FAQ: Finish Levels, 1/2 vs 5/8 and Safety Rules