Index

The following information can help you decide whether to attempt repair of damaged gyproc yourself, or to hire the experts. Repairing gyproc is not as hard as you may imagine; only a few tools are required. Just like anything else it gets easier as you gain experience, by doing. Digest the following information and decide for yourself.

How To Repair Gyproc Walls

GYPSUM DRYWALL

With the average person in mind, gyproc wall repair tips are provided here.

Gypsum is a mineral which contains 21 percent water in a crystallized form. About 50 percent of gypsum is water. This ability to hold water makes it a very good fire resistant material. When gypsum is subject to extreme heat, water in the gypsum is converted into steam, retarding any flames.

Gypsum wallboard is also great at deadening sound and the board is easy to repair. Gypsum wallboard can be painted, textured and wallpapered.

An 8 ft. sheet of gypsum wallboard weighs about 54 pounds. The sheets are shipped together in two's, but can be easily separated by removing the strip of paper which holds them together.

Gypsum drywall sheets come in lengths of 8, 9, 10, 12, 14 and 16 ft. They come in 1/4, 3/8, 1/2, and 5/8 inch thicknesses.

Drywall was developed in the late 1930's by United States Gypsum Company.
Before drywall, plaster was the popular choice.

The secret to produce a professional looking job

1/ Before applying tape or compound, remove all high spots; use a gyproc knife with a sharp blade to cut away the high spots. Use a hammer to lightly bang in nails that have popped out. You can easily fill a low spot, but a high spot will require a lot of sanding.

2/ Remove all loose material from around the repair area, any loose material will end up in the gyproc compound and will leave streaks as you draw the trowel over the surface. Very frustrating.

3/ Groove the edge of the repair joints to about 1/4 of an inch at 45 degrees. This provides space for the gyproc compound to enter and helps prevent cracking at the joints.

4/ Apply light coats of gyproc compound and allow to dry before applying the next coat.

You can buy gyproc compound unmixed or premixed. When you open the container, mix it gently as vigerous mixing will add air into the mix and will result in bubbles in the patch area; when these bubbles dry, small holes will appear in the dried compound. For small to medium jobs the premixed is the best choice. Apply a thin coat of gyproc compound over the area. Just a quick coat is all that is needed at this point; this will cement the fiber-glass tape to the wall and patch. Leave it for a day to dry thoroughly.
I find a three to four inch gyproc trowel is comfortable to use. Some refer to the gyprock trowel tool as a gyproc taping knife, but I find it confusing to use this wording here, as the term gyproc taping knife may be confused with with the gyproc cutting knife.

Apply enough coats, to allow for sanding and not expose the fiber glass mesh tape. Apply two or three light coats; one coat at a time. Allow enough time for each layer to dry before applying the next layer. Apply the gyproc compound four to six inches pass the end of the patch, which will spread out the height of the patch over a greater distance making it less noticeable when finished.
Remember to run the trowel over each layer when it has dryed, to knock off any burrs and high spots, before applying additional coats, this leads to a professional looking job. Place portable lighting to the side of the wall to show any imperfections on the wall.

Gypsum dust is a nuisance more than a hazard, so you can use a common disposable dust mask when sanding. Sand with a medium grit sandpaper using very little pressure. Finish up in a light circular motion. If you wish you can start with a sandpaper with 120 grit to remove material faster and then finish with a 150 grit sandpaper. An alternative to sanding is to use a polyurethane sponge, which provides a dust free method of removing material. Sanding helps texture the gyproc cement to match the existing gyproc wall. After sanding, it is ready to prime the area with an gyproc undercoat primer paint (gyproc primer is absolutely necessary or the patch will look smoother then the rest of the wall and have a shine). It is now ready for painting.

Patching small holes in gyproc

If you need to patch small holes like nail and screw holes you only need to make sure there is no lumps along the edge of the holes. Carefully cut away any protrusion or tap in the area around the hole to create a small indent. You can always fill a hole, but lumps are much harder to deal with. Apply a small amount of gyproc compound and scape away any excess. Let dry for a day, then lightly sand smooth and you are ready for painting. Even with small holes, the gyproc compound in the hole may shrink while drying and may require a couple of coats. If you have a very tiny nail hole to fill, apply a little gyproc compound or amazing enough, apply a little toothpaste with your finger, and it will do the job.

Patching medium size holes

To patch a medium size hole, just cut away any lumps or bumps with a sharp knife. Cover hole in a criss-cross fashion with fibre-glass tape, extending a couple of inches past the hole. Apply a first coat of gyproc compound and let dry. When dry run your trowel across the patch and knock off any bumps. Apply another coat and let dry. Continue this process untill you have covered the hole and you have a flat surface. Lightly sand when dry and you are ready to paint.

Preparing gyproc surfaces

Because the drywall is only 1/2 inch thick, it will contour to the surface. If the wall studs are not level, this will show in the finished wall, therefore it is very important to carefully prepare your walls before dry walling. Use a string to check your walls for bows, etc. Do a measurement of your wall stud placements and record this on paper for future reference to find the studs. If possible mark each studs position on the floor and ceiling, allowing for the thickness of the wallboard.

Cutting out electrical box placement

Coat the outer lip of the electrical box with soft chalk or lipstick. Next slide the drywall into place at the correct height and press it against the electric box. Lightly tap on the wallboard with the end of the hammer handle. This will leave an accurate impression of the electrical box. Cut outside the line to create a bit of clearance for easy installation.

Installing drywall

Cover the largest areas first. You may be able to use the smaller pieces that have been cut off. An added benefit is if you make a mistake in your measurement, you will still be able to use this sheet somewhere else.

Using joint compound

Before using joint compound from a bucket, mix it, blending it well. A well blended compound goes on smoothly. Don't overdue the mixing, as this can trap air in the compound that will go onto the wall as bubbles. When the bubbles pop, they will show up as small holes.

Sanding drywall

Sand off burrs, ridges and high spots with 120 grit sandpaper. Finish sanding with a 150 grit sandpaper.

Cleanup

When cleaning up don't wash a lot of gyproc compond dust down the drain
as this can clog up your drain pipes. Rather, first wipe down the gyproc tools
with paper towel and then finish up under the tap. Dry the tools to prevent
any rust from forming.

Clean up any spilled cement while wet. Scoop up what you can
and finish with a damp rag.

How to cut gyproc

To cut gyproc, you will need a gyproc knife. Use a sharp blade as dull blades will just tear the paper and will not cut properly. Do your measurements and pencil a line where you will cut. Lay the gyproc face up on a flat surface and lay a two foot square against the line, kneel on the small end of the square to keep it from moving while you are cutting. Draw the knife along the square, towards you and try to cut about half way through the gyproc; go over the cut a couple of times if necessary. Next bend one section of the gyproc to be cut, up at ninety degrees or a right angle. While holding the upped portion, run the gyproc knife towards yourself, along the line to be cut. Other cuts can be made with a handsaw with fine teeth.

If you are cutting out material for a light or electrical outlet use a gyprock saw ( tapered blade saw about six inches long with a handle). To start the cut, place the pointed end of the saw at one of the corners and gently rock the saw back and forth while applying some pressure. Next just saw along the line until you reach the end of the cut. finish with the other cuts.

Gyproc Dust Clean-up

Gyproc dust creates a real mess. if you step on it, it tracks all over the place. The dust is so fine it floats all over the room. The best way to deal with it is to trap as much as possible as you are sanding. Place an old bed sheet on the floor below the area you are sanding, then gently sand. Carefully wrap up the bed sheet and take it out side and give it a good shake. The little bit left around the room can be wiped up with a damp rag. Finish up with a vacuuming. A regular vacuum will tolerate a bit of gyproc dust, a large amount of gyproc dust will destroy your household vacuum cleaner. Empty the bag when you finish, even if is a new one. The dust plugs up the bag and prevents air from cooling the motor, which will cause the motor to overheat. A wet dry vacuum is best to clean up gyproc dust. There is available attachments for a vacuum cleaner which passes the dust through water before it enters the vacuum cleaner.

Popped Nails or Screws

Popped nails/screws occur anytime there is a space between the stud in the wall and the drywall. This is usually caused because the studs were not dried properly and contained excess moisture when it was installed. As the studs dried, a space became between the stud and wallboard appeared. To repair this problem drive the popped nail/screw below the level of the wallboard. Add a nail/screw above and below the popped nail/screw. Finish up with mudding, sanding and painting.

Water Damaged Gyprock

Extreme water damaged gyproc cannot be repaired because the outside paper covering looses it bond with the interior material which has swelled and crumbled. Any strength of the gyproc is gone, The only solution is to remove the water damaged gyprock and replace with new gyproc.

Nailing Framing Strips

When using powder-actuated nailers, to nail framing strips onto a block (cinder-block), aim for the center of the block. Cinder-blocks have a web in the center and ends, the rest is hollow.

If you are using masonry nails, drill pilot holes and drive the nails into the mortar joints.

Types of Gyproc

Standard, Flexible, fire-resistant, moisture resistant, abuse resistant, foil-backed, decorative, blue board, high density, cellulose-fiber sound proofing and mold resistant.

Gypsum wallboard Strength

Gypsum wallboard has a grain that runs parallel to the length, giving panels more strength along the length, rather than across the width.

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Tips on repairing, sanding, and painting gyproc, along with information on various types of gyproc. This article is written for the average person.