Drywall & Finishing: Gypsum Board Installation

Hanging and finishing new drywall generally runs $2.00 to $3.50 per square foot of wall and ceiling area, materials included. A standard 12 by 12 bedroom works out to roughly $1,400 to $2,400. Small repairs are priced by the job, not the square foot: a doorknob hole is usually a minimum call-out, and a water-damaged ceiling section runs $300 to $900 once the source has been fixed.

The single biggest driver of price is the finish level you need, and it is the part most quotes leave unstated. That is why we put it in writing before starting.

• Level 3. Fine under heavy texture. Not acceptable under flat or eggshell paint, where every joint will show.
• Level 4. The residential standard. Right for most walls under matte and eggshell finishes.
• Level 5. A skim coat over the whole surface. What you need under gloss paint, on a ceiling that gets raking light from a window, or on any large uninterrupted wall. Costs more and is the only thing that hides joints under those conditions.

Standard half-inch board covers most walls. Ceilings should get five-eighths or half-inch sag-resistant board — standard half-inch on ceilings framed 24 inches on centre will sag between the joists over time, and it is a visible wave you cannot fix with paint.

Bathrooms and laundry rooms want moisture-resistant board, and a tiled shower surround wants cement board rather than any paper-faced product. Putting regular drywall behind tile in a wet area is one of the most common shortcuts we get called to tear out, usually a few years later and usually with mould behind it. Garages and walls between a garage and living space have fire-rating requirements, which means five-eighths type X board and properly finished joints.

For anyone in this market: our humidity is high enough for long enough that the moisture-resistant choice is worth making in more rooms than the code strictly requires.

Finishing is three separate coats with drying time between them, not one thick pass. Tape coat embeds the tape, second coat widens and fills, third feathers the edges out wide enough that the transition disappears. Rushing the drying is what produces cracked joints and shrunken seams a month after the painters leave.

Sanding is where a good job is won or lost. We sand to a raking light — a work light held nearly flat against the wall, which throws a shadow off any ridge or dip the naked eye misses under overhead lighting. If a wall is not checked that way, the first sunny afternoon through a window will find every flaw for you.

Dust control matters in an occupied house. We seal openings, run containment and vacuum-sand where practical, and prime before we call it finished, because unprimed compound and unprimed paper absorb paint at different rates and the joints show through the first coat.

A hairline crack running diagonally from a door or window corner is usually normal settlement and a straightforward patch. A crack that keeps returning in the same place after a proper repair is a structural or moisture message, not a drywall problem, and refilling it every year is treating the symptom.

A brown or yellow stain on a ceiling means water, and the leak has to be found and fixed before any board goes back. Patching over an active leak hides it and costs far more later. Nail pops are the fasteners backing out as framing dries and shrinks, common in newer houses; the fix is to reset or replace the fastener and refinish, not to smear compound over the bump.