Drywall

The board

Gypsum board is a sheet of gypsum plaster faced with paper. Sheets are 4 feet wide, in lengths up to 12 feet or more, with the long edges slightly recessed so tape and joint compound can fill them flush ¹. Half-inch board is the usual wall material because it resists sagging between framing better than thinner board ¹; 5/8-inch goes on ceilings with wide framing and wherever fire resistance is required.

Hanging drywall is where a house’s framing either rewards or punishes you. Studs and joists that are out of line show up as wavy walls, so straighten crowned studs and add a strongback across ceiling joists in an unfinished attic before hanging anything ¹.

Layout

The International Residential Code’s rules are the practical standard (Wisconsin’s UDC doesn’t spell out general drywall fastening):

• Sheets go at right angles or parallel to the framing ².
• Every edge and end that runs parallel to the framing lands on a stud or joist; only edges perpendicular to the framing may fall between members ².
• Ceilings: run sheets perpendicular to the joists. Under a water-based texture, use at least 1/2-inch board at 16 inches on center and 5/8-inch (or 1/2-inch sag-resistant ceiling board) at 24 inches ².
• Walls: either direction. Horizontal sheets mean fewer vertical joints, so use full lengths where you can and put unavoidable butt joints over doors and windows ¹.
• Not where it gets wet: regular gypsum board isn’t installed where it’s directly exposed to weather or water ². Tub and shower walls get cement board or a manufacturer’s waterproof system.

Hang the ceiling first, then the walls, with the top wall sheet pushed up tight to support the ceiling’s edges.

Fasten it

Screws have replaced the nails the 1955 handbook describes. Typical spacing for 1/2-inch board is about 12 inches apart on ceilings and 16 inches on walls at 16-inch framing ². Drive each one so its head sits just below the surface, leaving a shallow dimple without breaking the paper ¹. A screw that tears through the paper isn’t holding anything; put another one beside it. A drywall screw gun with a depth clutch makes this automatic.

Tape and finish

The handbook’s taping sequence is still the method ¹:

1. With a 4- to 6-inch knife, fill the recessed joint with compound and press the paper tape into it until compound squeezes through.
2. Cover the tape with a thin coat, feathering the edges.
3. Let it dry, sand lightly, and apply a second coat wider than the first, feathered.
4. A third coat, wider still, feathered beyond the second.
5. Sand smooth when dry.
6. Fill every screw dimple with compound, twice, sanding between coats.

Inside corners get paper tape folded down the center and bedded in compound; outside corners get metal or paper-faced corner bead ¹. Butt joints (the unrecessed ends) build up a hump, so feather them extra wide.

The garage wall

An attached garage holds cars, fuel, and solvents, so Wisconsin requires a fire separation between it and the house. The walls and ceiling between them, including attic and soffit areas, must be one of ³:

• one layer of 5/8-inch Type X gypsum on the garage side;
• one layer of 1/2-inch gypsum on each side;
• two layers of 1/2-inch on the garage side.

Joints must be taped (or tightly fitted and backed) ³, and the door between garage and house must carry a label showing at least a 20-minute fire rating ³. Beams and columns in the garage that hold up living space above need the same protection ³.

What to take from this

Run ceiling sheets across the joists and land every parallel edge on framing; use 1/2-inch board at 16-inch spacing and 5/8 or sag-resistant 1/2 at 24 inches under texture. Screw about every 12 inches on ceilings and 16 on walls, set just below the paper. Tape in three widening, feathered coats and fill screws twice. Keep regular board out of wet areas, and build the garage separation to SPS 321.08: 5/8-inch Type X on the garage side (or the equivalents), taped joints, and a 20-minute door.