I've put my fair share of holes in walls in my youth. When I bought a foreclosure for my first home, I learned about fixing them. It's actually pretty easy, but a professional might charge you a few hundred dollars anyway. I'm going to show you how to fix huge holes so that you never knew they were there.
Step 1: Gather Your Tools
Don't waste money on those drywall repair kits. Here's what you need:
- A drywall "project panel". These are usually less than $5 at your home improvement center, and they measure 24"x24". If you think you'll need to repair more than a few holes, than a 4'x8' sheet of drywall is about $12.
- Polystyrene 1x2 moulding and...
- A saw to cut it with.
- Spackle or joint compound. You can't go wrong either way. Spackle makes sense for most people - joint compound is more for if you're going to be putting up a lot of drywall. I'm going to use the two terms interchangeably here, but know that there are subtle and important differences between them - mostly in the area of cost.
- A can of paint that matches your walls color. If it wasn't the original paint, then just get close for now, and commit yourself to repainting the entire wall later on. The funny thing about paint is that even the same paint code doesn't look the same over time because manufacturers often change the chemistry of the base.
- Painting tools, including a paint brush, paint roller and paint tray.
- A timber framing square.
- A carpet knife.
- A putty knife.
- A screwgun.
- Drywall screws.
- A sanding block with 100 grit paper attached (or a 100 grit sanding sponge).
Any project that involves guns and knives ought to be fun...
Step 2: Measure Your Hole
Using your timber framing square, measure an area around the hole for length and width. I like to add plenty of room because however big the hole is on the surface, it's often bigger on the outside. Give yourself 2" to 3" extra, or use a minimum panel size of 6" x 6".
Step 3: Transfer Measurements
Using your timber framing square, transfer your measurements onto your patch panel. You can also use your timber framing square as a straight edge to score the cuts with a carpet knife. After 2-3 firm passes with the carpet knife, you won't need the square anymore.
Don't try to cut through the drywall all at once. Just keep making repeated passes with the carpet knife. Yes, this will kill the blade almost immediately, but it gives you a nice clean edge. Blades are cheap, and you probably are due to replace it anyway.
You could use a drywall saw or other tool to saw this panel out. I find that they leave very rough edges that require additional cleanup. The carpet knife leaves a nice, clean, almost surgical edge. My OCD compels me to that result.
Step 4: Your Patch Is Your Guide
Lay your patch over your hole, and trace around it. The result is a hole that is only slightly larger than your patch panel. This is part of the secret to making the repair invisible. If you tried to cut a hole then cut a patch to match the hole, there would be huge gaps between the two. The joint compound in those gaps would eventually separate, leaving tiny cracks.
Step 5: Make Support Braces for the Patch
Cut the polystyrene 1x2 trim into two sections that are 2" - 3" longer than the hole is top to bottom. Place these inside the wall, the drive drywalls screws through the drywall and into the 1x2's to hold them firmly against the inside of the wall. This is what your patch will attach to.
I can't emphasize the importance of this step. Actually, I can: the choice of polystyrene over just wood is for two reasons. One, wood tends to split when you drive a screw into it. That doesn't make for a very secure connection. For another, wood swells with moisture, causing it to shift around. Polystyrene doesn't have that problem. If you had anchored this piece of drywall to an existing stud or used wooden 1x2's, a few years of changing indoor humidity would push and pull the patch around, causing it to separate from the surrounding drywall.
Real quick - with a piece of sandpaper on a sanding block, go head and knock off the edges both around the hole and the patch. This will prevent them from sitting proud and leaving a visible seam.
Step 6: Install the Patch
Now put the patch into the hole, and secure it in place with a few screws. A few things to watch for:
First, make sure all screws are slightly countersunk below the surface - about 1/8" of an inch is fine, but not much more than that. We'll want to press the joint compound into these holes in the next step to hide the screws.
Second, make sure you leave an even gap around the edges of the patch. If the patch is butted against the drywall, we won't be able to force any joint compound (or spackle) into this gap, and that will leave a noticeable seam.
Step 7: Spackle That!
But wait... pro-tip... if you try to apply spackle/joint compound to dry drywall, the paper covering on the drywall will suck the moisture out of it. So get yourself an old rag, make it damp - not dripping wet - and wipe down the surrounding wall and patch panel. This will also help the joint compound adhere to the paper.
Load your joint compound on your putty knife, and just smash it into the gaps. We want to fill those gaps, and also the holes left over the drywall screws. Push it in, then knife it smooth. Technique helps here. Hold the knife at a 45-ish degree angle as you pull the joint compound around. Use a medium pressure and a medium speed. Once you've filled in all the gaps and holes, go ahead and spread light film over the patch and out to a 1" margin around the patch panel. If it helps you feel better about this part of the job, then do your best Bob Ross impression. Mix a little titanium white with some thalo blue...
Step 8: Sand It Smooth
Give the joint compound plenty of time to dry. We're talking 3 hours here. Much of it will dry within an hour, but the screwheads and seam will take longer.
With your 100 grit sanding block (I prefer the block, but you can use a sponge), slowly sand over the entire patch using a circular motion. Don't stay in one spot too long, or you'll leave a dip.
It's hard to visually tell when you're done sanding - the bright white of the joint compound tends to hide defects that magically pop out when you start to paint. But your hand never lies - gently rub your hand over the patch panel, and feel with your finger tips. High spots will need to be sanded a little more. Dips will need to have more joint compound knifed on. (Really thin layers only need about an hour to dry.)
This step creates a lot of dust. For a small patch panel like this, you can just try to avoid the dust like I did in the video, but I highly recommend that you use a face mask or respirator, as well as goggles. This is particularly true if you're going to do a lot of drywall work - the dust is listed as an occupational hazard, and tradesman typically wear googles and respirators, if not body suits. (It makes cleanup easier, too.)
Step 9: Paint Like a Boss
Note: User giedrius.dyra pointed out that I didn't put down anything to protect the carpet. I actually plan to put in laminate flooring - and yes, there will be an Instructable for that - so I wasn't worried about it. You, on the other hand, should definitely get some thick plastic sheeting and tape it to the base board. When you roll, little bits of paint will get flicked around, so cover the floor about 4 get in all directions.
First, the freshly sanded joint compound will soak up moisture like a sponge, and that will show up as a difference in color and texture in the finished product. To start, I recommend loading up the end of a brush with a generous level fo paint, and tabbing it around the seams and over the screw heads. After a few seconds of excess paint sitting on those areas, brush it out in long feathering strokes. Again, feel free to channel Bob Ross here.
After that first brushing of paint has dried, come back with a roller. Chances are, your wall was originally painted with a roller, and that resulted in that specific "egg shell" texture. Using a roller will achieve that same texture and blend in the patch area. You'll want to roll the paint over a much wider area than the patch itself, and let the roller run dry - that is, don't reload the roller, but just let the paint kind of roll off into the dry areas. This will help the patch area blend better. As the paint dries, the difference in colors will disappear. The end result: a perfect patch.