Drywall Installation Inspection

Per ASTM C840 and IRC R702.3.5, studs shall be spaced no more than 16 inches on center for 1/2-inch drywall and 24 inches on center for 5/8-inch drywall. Studs must be plumb within 1/4 inch in 8 feet.

1. Verify stud spacing with a tape measure — should be 16" or 24" OC depending on board thickness

2. Check studs for plumb using a 4-foot level

3. Look for twisted or bowed studs that would cause bulges in the finished surface

4. Verify backing at all corners and intersections

- Studs spaced too far apart causing board sag

- Twisted studs creating uneven surface

- Missing backing at corners or above openings

- Non-standard framing at windows and doors

Per ASTM C840, screws shall be spaced no more than 12 inches OC on ceilings and 16 inches OC on walls. Screws must be driven so the head is slightly below the surface without breaking the paper face. Minimum edge distance is 3/8 inch.

1. Verify screw spacing — 12" OC max on ceilings, 16" OC max on walls

2. Check that screw heads are slightly dimpled, not driven through paper

3. Verify minimum 3/8" edge distance from board edges

4. Look for any popped or protruding fasteners

- Over-driven screws that break paper face (reduces holding power)

- Under-driven screws that protrude above surface (visible through finish)

- Screws too close to board edges causing crumbling

- Insufficient number of fasteners

Per GA-216, all joints must be taped and finished to the specified level (Level 1-5). Level 4 is standard for most residential applications. Joint compound must be feathered smooth with no ridges, tool marks, or bubbles.

1. Use a raking light (bright light at a low angle) to check for imperfections

2. Run a 4-foot straightedge across joints — deviation should not exceed 1/16 inch

3. Check for tape bubbles or delamination by pressing along taped joints

4. Verify all joints, corners, and fastener heads are properly coated

- Visible tape edges or ridges through finish

- Bubbles under tape from insufficient compound

- Excessive buildup creating visible humps

- Inconsistent finish level across surfaces

Per ASTM C840, corner beads must be straight and securely attached. Metal corner beads should be fastened every 9 inches. Vinyl corner beads must be adhered per manufacturer specifications.

1. Sight down all outside corners for straightness

2. Check that corner beads are securely attached with no movement

3. Verify compound coverage over corner bead flanges

4. Inspect trim pieces around windows, doors, and ceiling transitions

- Dented or kinked corner beads

- Corner beads not straight or twisted

- Insufficient compound coverage showing metal through finish

- Gaps between corner bead and adjacent surfaces

Per IRC R302.4, openings around electrical boxes, pipes, and other penetrations shall be sealed with fire-rated caulk or approved materials. Gaps around boxes shall not exceed 1/8 inch.

1. Inspect cutouts around electrical boxes — should be tight with no more than 1/8" gap

2. Check pipe penetrations for proper sizing and sealing

3. Verify HVAC register openings are clean-cut and properly sized

4. Confirm fire-rated assemblies have proper firestopping

- Oversized cutouts around electrical boxes

- Rough or jagged cuts around penetrations

- Missing firestopping at rated assemblies

- Gaps allowing air infiltration

Per IRC R702.3.8, moisture-resistant (green board) or cement backer board must be used in wet areas. Standard drywall is not permitted in bathrooms, laundry rooms, or other areas subject to moisture exposure.

1. Verify moisture-resistant board is used in all wet areas (bathrooms, kitchens, laundry)

2. Use a moisture meter to check board moisture content — should be below 1%

3. Confirm cement board or equivalent is used behind tile in shower/tub areas

4. Check that bottom edge of drywall is at least 1/2" above floor in wet areas

- Standard drywall used in wet areas instead of moisture-resistant type

- Drywall touching the floor in bathrooms

- No cement board behind shower tile

- Water damage from construction moisture not dried before enclosure