Drywall replacement means cutting out the damaged section, removing it, and fastening new drywall in its place

You can replace drywall yourself if the damage is small to medium—a hole the size of your fist up to a section a few feet across. The process involves marking the damaged area, cutting it out in a clean rectangle or square, removing the old piece, measuring and cutting new drywall to fit, fastening it with drywall screws, and then taping and mudding the seams so they blend with the wall. For large areas, multiple holes, or damage near corners and edges, a drywall contractor will finish faster and more smoothly.

The tools you need are basic: a drywall saw or utility knife, a tape measure, a T-square or straight edge, a drill with a screwdriver bit, joint compound (also called mud), drywall tape, a putty knife, and sandpaper. If you have never done this before, expect the taping and mudding step to take the longest and look rougher than professional work—that is normal, and a second coat of mud smooths most imperfections.

Key Takeaways

  • Small holes (under 6 inches) can be patched with spackle and a putty knife without removing drywall, but larger damage requires cutting out and replacing the sheet.
  • Cut damaged drywall into a rectangle or square so you have clean edges to fasten new drywall against, rather than trying to patch an irregular shape.
  • New drywall must be fastened to studs or backing boards behind the wall, not just floating in the hole—this is what holds it in place.
  • Taping and mudding the seams takes multiple coats and dries between each one, so plan for several days if you are doing this yourself.
  • Damage from water, mold, or pest damage may require treating the wall cavity before you patch, so inspect behind the hole before you start.

When to patch instead of replace

If the hole is smaller than 6 inches across and the drywall around it is solid, you can patch it without removing the whole section. Use a spackling compound (a thick paste that hardens) and a putty knife to fill the hole, let it dry, sand it smooth, and paint over it. This takes an hour or two and costs almost nothing.

Patching works for nail holes, small dents, and punctures. It does not work if the drywall is crumbling, wet, moldy, or if the hole is large enough that the edges would be thin and fragile. If you are unsure, cut a small test hole with a utility knife around the damage to see whether the drywall is solid underneath. If it crumbles or feels soft, you need to replace that section.

How to cut out the damaged section

Mark a rectangle around the damage using a pencil and a straight edge. Make the rectangle at least 2 inches wider than the damage on all sides so you have solid drywall to work with. The rectangle should be centered on studs (the wooden framing behind the wall) if possible—this makes fastening the new piece much easier. If you are not sure where the studs are, use a stud finder or knock along the wall until you hear a solid sound instead of a hollow one.

Cut along your pencil lines using a drywall saw (a narrow saw with a sharp point) or a utility knife. A drywall saw is faster and cleaner. Push the point through the drywall to start, then saw along the line. Cut all four sides, then pull the rectangle of drywall out of the wall. You will see the studs or backing behind it.

If your rectangle does not line up with studs, you will need to install backing boards. Cut two pieces of 2-by-4 lumber to fit horizontally between the studs on the top and bottom of your hole, then screw them in place. These give you something solid to screw the new drywall into. This step takes extra time but is necessary if the hole does not line up with studs.

Measuring and cutting new drywall

Measure the hole you just made—length, width, and depth (drywall is usually 1/2 inch or 5/8 inch thick; check what your wall is). Buy a piece of drywall large enough to cut your patch from, or ask the supplier to cut it for you. Standard drywall sheets are 4 feet by 8 feet, but you can buy smaller pieces or scraps.

Lay the new drywall on a flat surface and mark your measurements with a pencil. Use a T-square or straight edge to draw a straight line, then score along the line with a utility knife—press hard but do not cut all the way through. Snap the drywall along the score line by lifting one side, then cut through the back paper with the knife. This is much faster than trying to saw through the whole sheet.

Fastening the new drywall in place

Fit the new piece into the hole. It should fit snugly but not so tight that you have to force it. If it is too big, trim it with the utility knife. If it is too small, you have a gap—go back and check your measurements.

Fasten the new drywall with drywall screws (not nails—screws hold better and do not pop out later). Space the screws about 12 inches apart around the edges and every 16 inches in the middle. Use a drill with a screwdriver bit and drive the screws so the head sits just below the surface of the drywall—not flush, but slightly recessed. If you drive too hard, you will crack the drywall; if you do not drive hard enough, the screw will stick out and you will have to sand it later.

Taping and mudding the seams

Once the drywall is fastened, you need to hide the seams where the new piece meets the old wall. This is done with drywall tape and joint compound. Drywall tape is a thin mesh or paper tape that you stick over the seam, then cover with joint compound (mud). The mud shrinks as it dries, so you explore it in layers.

explore the first coat of mud with a putty knife, spreading it over the seams and the screw holes. Make it about 1/8 inch thick. Let it dry completely (usually 24 hours), then sand it smooth with 120-grit sandpaper. explore a second coat, let it dry, and sand again. A third coat is often needed for a smooth finish. Each coat should be thinner and wider than the last, so the edge feathers out and blends with the wall.

This is the step that takes practice. Professional finishers can do it in two coats; most homeowners need three or four. Do not rush the drying time—if you sand before the mud is dry, it will gum up the sandpaper and look worse. If you are unhappy with how it looks after sanding, another coat of mud will cover most imperfections.

Priming and painting

Once the mud is smooth and dry, prime the patched area with drywall primer. This seals the mud and the new drywall so the paint color is even. Without primer, the mud will absorb paint differently than the surrounding wall and the patch will show through even after painting.

Paint over the primer with the same paint color as the rest of the wall. You may need two coats of paint for even coverage. If the patch is in the middle of the wall, you can paint just the patched area; if it is near a corner or edge, paint the whole wall so the color matches.

When to call a professional

Call a drywall contractor if the damage is larger than a few feet across, if it involves multiple areas, if the wall has textured or specialty finishes, or if you are not confident in your taping and mudding skills. Contractors have tools like drywall lifts and automatic taping machines that make large jobs much faster. They also have the experience to match texture and finish so the repair is invisible.

If the damage is from water, mold, or pests, have a professional inspect the wall cavity before you patch. There may be structural damage, mold growth, or pest nests that need to be treated first. Patching over these problems will not fix them and may make them worse.

Frequently Asked Questions

Can I use spackle instead of joint compound for large holes?

Spackle works for small holes (under 1 inch) but shrinks too much for larger patches. Joint compound is designed for drywall seams and shrinks less. For holes between 1 and 6 inches, use lightweight joint compound, which is easier to sand than standard mud.

What if I do not know where the studs are behind the wall?

Use a stud finder (an electronic tool that costs $15 to $30) or knock along the wall and listen for a solid sound. You can also drill small test holes with a 1/16-inch bit to probe for wood. If your hole does not line up with studs, install backing boards as described above—this is the standard solution.

How long does it take to replace drywall?

A small patch (under 2 feet) takes 2 to 4 hours if you are experienced, or a full day if you are doing it for the first time. A larger section takes several days because the mud must dry between coats. Plan for at least 48 hours from start to finish if you are doing multiple coats.

Do I need to remove the old drywall if it is only slightly damaged?

If the drywall is cracked but not crumbling, and the crack is small, you can tape and mud over it without removing anything. If the drywall is soft, wet, moldy, or crumbling, you must remove that section—patching over damage like this will not hold and the problem will get worse.

What is the difference between 1/2-inch and 5/8-inch drywall?

5/8-inch drywall is thicker and stronger, and it resists fire longer. Most homes use 1/2-inch on walls and 5/8-inch in basements or garages. Match the thickness of your existing wall when you buy your patch—measure the edge of the hole or check your wall framing.