Getting a Riverside room ready for drywall repair
Most of the trouble in a drywall repair shows up before the first knife of compound goes on. Dust travels into every room, the furniture is in the way, the wall is still damp from the leak that caused the damage, or the old paint is peeling at the edges of the patch. A few hours of preparation in a Riverside house saves a day of rework, and the steps are the same whether the damage is a single hole or a whole stretch of wall.
What should be moved out of the room first?
Everything that can be carried comes out: lamps, rugs, wall art, curtains and anything on a shelf near the repair. Large furniture that cannot leave gets pulled to the middle of the room, away from the wall, and wrapped in plastic sheeting. Sanding joint compound makes a fine white powder that gets into upholstery, vents and the gaps around books, and it does not wipe off cleanly once it settles.
Switch plates and outlet covers come off as well, because compound lands on them and a repair that stops short of the outlet box looks unfinished. Take a photo of the wiring behind a cover before removing it if there is any doubt about which wire goes where. If the repair is close to a light fixture or smoke detector, turn off the breaker for that circuit before anyone works nearby.
How is dust kept from spreading through the house?
Dust control has three parts: sealing the room, catching dust at the source, and cleaning in the right order. Sealing means taping plastic sheeting over the doorway and closing the heating and cooling vent in the room. In the Inland Empire the air conditioner runs for much of the year, and an open return vent will pull fine drywall dust into the ductwork and distribute it through the whole house.
Catching dust at the source means sanding with a pole sander or a hand block attached to a vacuum hose, or using a damp sponge on the final pass. A wet sponge leaves a very light surface on the compound and puts almost nothing in the air, though it takes more care near the edges of a patch. Cleaning goes from top to bottom: ceiling and walls, then the floor, and a vacuum with a fine filter, not a broom, which only lifts the dust back into the room.
How dry does the wall need to be?
A wall that feels dry to the hand can still be damp at the core. After a plumbing leak or a roof leak the gypsum board holds moisture longer than the paper face suggests, especially along the bottom edge and around the framing. A pin-type moisture meter pressed into the board will read the water content, and the numbers should match a section of untouched wall in the same room before any compound goes over the damaged area.
Riverside's dry air helps a great deal. A room with the windows cracked and a fan running will often dry out in a day or two in summer, where a coastal house might take a week. The Box Springs Mountains channel warm, dry air through the valley for much of the year, and that same dryness can cause trouble later, since compound applied over a wall that is still damp will blister and shrink as the moisture leaves.
What happens with old paint around the repair?
Loose paint is removed first. Scrape the area around the damage with a flexible putty knife until the blade stops catching on flakes. Paint that is still tight to the surface can stay, but the edge where it meets bare board has to be feathered with sandpaper, since an abrupt step in the paint will show through the new coats as a ridge. In older homes near the University of California Riverside campus and downtown, there may be several layers of paint, some of them oil-based, and these chip in sheets rather than flakes.
Houses built before the late 1970s can have lead in the paint, and sanding it releases dust that is hazardous to breathe. The sensible approach is to test the paint with a home kit before any sanding, and to hire a certified renovator when the result is positive. Dry sanding old paint with an unknown history is the one step in preparation that cannot be undone once the dust is in the air.
Do the edges of a hole need any shaping?
Yes. A hole with ragged paper edges takes compound badly, because loose paper fibers lift and bubble as the mud dries. The edges should be cut with a utility knife so the paper is cleanly severed, with the cut sloping slightly inward toward the center. Where the paper face has torn away from the gypsum core around the hole, cut back until the paper holds firmly when pressed with a finger.
A square or rectangular opening is easier to patch than a circle, because a straight-edged piece of new board fits tightly against four straight sides. Draw the square around the damage with a pencil and a straightedge, cut along the lines with a drywall saw or a knife, and the patch piece can be traced directly from the opening. Leave the corners square and slightly sharp, since a rounded corner leaves a gap that takes extra compound to fill.
What tools and materials should be on hand?
A tidy set of materials makes the work go in order, with no stopping halfway to find something. For most patches the list is short:
- A utility knife with fresh blades and a drywall saw
- Six inch and ten inch taping knives, plus a mud pan
- Setting compound for the first pass and all purpose compound for the finishing coats
- Mesh tape or paper tape, matched to the type of seam
- A pole sander, fine sanding sponges and a dust mask rated for fine particles
- Drop cloths, plastic sheeting and painter's tape
- Primer, a roller, and a small brush for cutting in
Mixing is where many beginners lose time. Setting compound hardens on a clock, so only as much as can be used in about twenty minutes should be mixed at once. Ready-mixed all purpose compound keeps for months in a closed bucket, and a small amount can be thinned with a splash of water to improve how it spreads on the final coats.
How long should the whole job be allowed to take?
A single small patch takes two or three working sessions, with the drying time between them being the real schedule. A hole filled with setting compound can take a second coat after an hour or so. Coats of all purpose compound need to dry overnight in most conditions, and a thicker application takes longer. Sanding, priming and painting add another day if each step is allowed its full cure time.
Rushing the cure is the most common way to ruin an otherwise clean repair. Compound that looks dry on the surface can still be wet beneath, and sanding it clogs the paper, smears the surface and leaves a rough patch that has to be redone. Pressing a thumbnail into the edge of the compound is a simple test: if it leaves a mark, the coat is not ready.
Is it worth checking the wall behind the repair?
Before closing up any opening larger than a hand, look into the cavity with a flashlight. Wiring, pipes and insulation are all visible, and so are signs of earlier trouble, such as stained wood, rusted fasteners or a musty smell. In houses near the Santa Ana River, where the ground stays damp in places, moisture problems in a wall cavity are worth a closer look before a new piece of board hides them.
Where do Riverside homes differ from others?
Riverside County covers a wide range of housing, from Craftsman bungalows around the Mission Inn district to tract houses built in the decades after the war, and each style brings its own repair conditions. Older plaster-and-lath walls look like drywall from the outside but behave differently, and a plaster wall needs a different patching method. A quick knock on the wall tells the story: plaster sounds hard and dense, while drywall sounds hollow.
What is the last check before work starts?
Walk the room once more with a flashlight: floor covered, vent sealed, covers off, edges cut clean and the board behind dry. With those in place, the repair itself is the easy part.