Drywall, also known as plasterboard, wallboard, or gypsum board, is a popular building material used for interior walls and ceilings in homes and commercial buildings. Though durable, drywall can develop problems over time that require repair. Here we discuss the most common drywall issues homeowners face and provide solutions to fix them.
Causes of Drywall Damage
Drywall can become damaged due to:
- Normal wear and tear – Drywall naturally degrades over time, especially in high traffic areas. The keys around doorknobs can poke holes, corners can get bumped and dinged, and nails or screws can work themselves loose.
- Water damage – Leaky roofs, plumbing leaks, flooding, and high humidity can warp, stain, or deteriorate drywall. Water damage provides an environment for mold growth as well.
- Settlement and movement – If the foundation or framing studs shift over time, drywall can crack at the seams and corners. Earthquakes, reuse an old house’s structure, or wrongly spaced framing members increases the chance of settlement issues.
- Poor installation – Drywall that wasn’t properly installed or secured can sag, crack, and come loose over time as the house settles. Short screws or nails allow the drywall to detach from the studs.
Knowing the root cause of the damage helps determine the best solution. Let’s explore common problems and how to fix them.
Holes and Dents in Drywall
Holes of any size need patching to prevent further damage. Large holes may require cutting and replacing whole drywall sheets. Smaller holes and dents can be easily repaired.
Supplies Needed
- Drywall joint compound
- Joint tape (for large holes)
- Drywall patching compound
- Putty or utility knife
- Sandpaper
- Paint to match existing color
Steps to Patch Small and Medium Holes
- Remove any loose drywall or debris around the hole and clean the area so it’s free of dust.
- For holes up to 3 inches wide, apply a thin layer of joint compound over the hole and surrounding area using a putty knife. Feather the edges so they smoothly taper off.
- Let the joint compound fully dry as per the manufacturer instructions, usually 24 hours.
- Lightly sand the patched area to smooth away any ridges or uneven areas.
- Apply a second thin coat of joint compound over the first coat, feathering the edges again. Let dry completely.
- Lightly sand the area smooth and use drywall primer to spot prime. Once dry, paint with a color matched to the existing wall color.
- For larger holes up to 6 inches wide, secure metal or fiberglass joint tape over the hole using joint compound. Apply a thin layer over the tape and let dry before lightly sanding. Then apply 1-2 more thin coats of compound, drying and sanding between each application to blend with the surrounding wall.
Steps to Patch Large Holes
- Measure the hole and cut a piece of drywall to fit, making sure it’s slightly larger than the hole.
- Secure the replacement drywall with drywall screws into the studs or use nails for wood lath. The patch should sit flush with the existing wall.
- Tape over the seams between the patch and old drywall using joint tape and compound. Let dry.
- Finish as above, applying 2-3 thin coats of compound over the tape, sanding between coats. Smoothly blend edges into the wall.
- Prime and paint the patched area once completely dry.
Cracks in Drywall Seams and Corners
Cracks often appear along drywall seams and corners as homes shift and settle over time. Thankfully they are easy to fix using joint compound and tape.
Supplies Needed
- Joint compound
- Drywall joint tape
- Putty knife
- Sandpaper
- Drywall primer and paint
Steps to Fix Cracks
- Widen the crack slightly using a utility knife to create a “V” shape. This helps the compound adhere.
- Apply joint compound over the crack, forcing it into the “V” shape with a putty knife. Smooth to feather the edges.
- Embed joint tape over the crack using a thin layer of compound over the tape. Smooth it gently over the tape.
- Let the compound fully dry, usually 24 hours. Lightly sand to smooth bumps or ridges.
- Apply a second coat of joint compound, extending it about 2 inches beyond the tape onto the wall surface. Feather the edges.
- Let dry completely, then lightly sand. Follow with a final thin, wide coat of compound, feathering the edges to blend.
- Once fully dry, prime and paint the area. Use a paint color matched to the existing wall color.
For corner cracks, simply embed tape in compound over the cracked seam as outlined above. feathering the edges on each wall surface.
Sagging or Detached Drywall
Over time, drywall can sag or even become detached from studs or furring strips. This requires re-securing it with new screws or nails.
Supplies Needed
- Drywall screws or ring shank nails
- Electric drill with Phillips bit
- Joint compound
- Drywall tape (for detached drywall)
- Sandpaper
- Drywall primer and paint
Steps to Fix Sagging or Detached Drywall
- Identify where the wall studs are using a stud finder. Mark their location.
- For sagging drywall, drive in new screws spaced about 8 inches apart directly into the studs underneath.
- For detached drywall, pull the loose board tight against the studs and drive in new screws every 8 inches to re-secure to the framing.
- If the tear is large, secure reinforcing joint tape over it using joint compound. Feather the edges.
- Apply 1-2 thin coats of joint compound over screw holes and seams to smooth the repairs. Sand lightly between coats.
- Spot prime once fully dry. Paint with a color matched to the existing wall.
Adding insulation between detaching drywall and the studs can help reduce future sagging or detachment too.
Mold or Mildew on Drywall
Excess moisture is the culprit when mold and mildew growth occurs on drywall surfaces. Fixing drainage and moisture problems is key before repairing walls.
Supplies Needed
- Concrobium or similar mold cleaner
- Stiff scrub brush
- Sandpaper (for affected drywall paper)
- Drywall primer and paint
- Joint compound (for damaged areas)
Steps to Remove Mold and Mildew
- Put on protective gloves, goggles, and a mask to prevent contact or breathing in mold.
- Clean the moldy areas using an antimicrobial cleaner like Concrobium by generously spraying and allowing to soak in 5-10 minutes.
- Scrub affected areas with a stiff brush and rinse clean with water. Repeat as needed.
- Once mold is removed, sand lightly to rough up any damaged drywall paper facing. This helps the paint adhere.
- Spot prime sanded areas with drywall primer. Use a stain-blocking primer for any remaining stains.
- Repair any dried out, cracked or damaged drywall using joint compound as outlined above. Smooth and feather edges.
- Once repairs are made and primer dries, paint walls with a mold-resistant paint in a color matched to the existing non-damaged wall area.
Reducing indoor humidity levels can also deter mold regrowth after removing it. Proper ventilation is key.
Water-Damaged Drywall
Water damage can ruin drywall quickly, so it’s important to dry it out and replace damaged sheets promptly after flooding or leaks.
Supplies Needed
- Pry bar
- Utility knife
- Screw gun or hammer
- Drywall sheets
- Joint compound
- Drywall tape
- Drywall screws
- Primer and paint
- Dehumidifier/fans
Steps for Drying and Replacing Water-Damaged Drywall
- Dry out affected areas ASAP using dehumidifiers and fans. Don’t let wall cavities sit wet for over 24-48 hours.
- Remove base trim from wet walls. Cut drywall 2 feet above the water line and pull away. Discard any insulation or vapour barrier.
- Cut out additional damaged drywall as needed to expose wall studs. Remove drywall screws.
- Cut replacement drywall to size and install on studs using drywall screws every 8 inches.
- Fill seams between sheets with joint compound and embed tape. Apply 2-3 thin coats, drying between each. Sand smooth.
- Seal raw gypsum board edges with primer before applying final coat of compound at seams. This prevents uneven absorption.
- Prime and paint once fully dry. Use stain-blocking primer for any lingering water stains.
Take steps to remedy the water source as well to prevent ongoing drywall damage in the future.
Drywall Popping Screws or Nails
As homes shift and settle, drywall fasteners can work loose and pop through the drywall surface. This is common with improperly spaced framing.
Supplies Needed
- Drywall screws
- Electric drill with Phillips bit
- Hammer
- Joint compound
- Drywall primer and paint
Steps to Repair Popping Screws or Nails
- Remove any loose or popped fasteners. If still attached to a stud, drive it back in fully with a hammer.
- Insert new drywall screws about 1 inch away from the original on the same underlying stud.
- Drive in alternate screws spaced evenly, 8 inches apart down the stud line. This spreads out tension.
- Ensure all fastener heads sit just below the drywall surface without puncturing the paper.
- Apply a thin coat of joint compound over the screw heads and any existing nail holes. Feather the edges smooth.
- Let dry fully and sand lightly to blend before priming and painting.
Adding construction adhesive along the studs can help anchor drywall in place to prevent fasteners from popping again.
Fixing Drywall Corner Bead
Metal or plastic corner bead covers and reinforces outside drywall corners. But impact damage or shifting studs can deform or pop it off.
Supplies Needed
- Replacement corner bead
- Utility knife
- Joint compound
- Drywall screws or nails
- Hammer
- Putty knife
- Sandpaper
- Primer and paint
Steps to Replace Damaged Corner Bead
- Carefully cut through the drywall paper seam where the corner bead meets the wall using a utility knife.
- Pull the corner bead away from the drywall without damaging the surrounding paper facing.
- Remove any remaining drywall facing from the corner and cut back detached paper.
- Cut replacement metal or plastic corner bead to fit the corner length using snips.
- Attach the new corner bead with drywall screws or nails every 6-8 inches along studs.
- Embed and smooth joint compound over the corner, letting dry between coats. Lightly sand.
- Finish surrounding damaged facing with compound as outlined above to blend with corner.
- Once corner fully dries, prime and paint to match existing wall color.
Adding wood glue or construction adhesive helps reinforce the bond between corner bead and drywall.
Common Drywall Repair Questions
Below are answers to some frequently asked questions about repairing damaged drywall:
What’s the best drywall primer to use before painting repairs?
Look for an interior drywall primer formulated especially for new drywall repairs. These seal raw gypsum edges better than standard primers. Popular options include Zinsser Drywall Pro-999 and Sherwin-Williams ProMar 200 Zero VOC Drywall Primer.
Should I use mesh tape or paper tape to repair drywall cracks and seams?
Paper joint tape generally provides the strongest drywall seam repairs. Fibreglass mesh tape is easier to use for DIY repairs but is prone to cracking long-term as the house settles. Paper tape withstands contraction and expansion better.
How long does joint compound need to dry before sanding or applying another coat?
Joint compound typically fully dries within 24 hours. Quick-set compounds can dry in under an hour. Always let each coat fully dry before adding another or sanding. Never apply a new coat over compound that feels cool or damp.
What grit sandpaper is best for smoothing joint compound between coats?
Lightly sand joint compound repairs using 150-220 grit sandpaper between coats. Very fine grit around 400 can be used for final touch-ups to achieve an ultra-smooth finish. Be sure to avoid scuffing the drywall paper.
Should I prime repaired drywall before painting or just paint directly over it?
Priming ensures paint adheres properly to joint compound repairs and provides the best finish. The porous compound absorbs paint differently than drywall paper and can leave a mottled appearance without primer.
How do I match the drywall texture after repairs to blend with the existing wall?
Capturing the surrounding texture makes repairs less noticeable. Lightly blot wet joint compound with a wadded paper towel to emulate an orange peel or splatter texture. Use a drywall brush or dull knife over compound to match a knockdown texture.
Summary
Drywall is a versatile and easy to repair wall covering that can develop a variety of issues over time. Settlement cracks, nail pops, water damage, and mold growth are common problems that arise. Thankfully, most drywall damage can be fixed using basic tools and patching techniques. Carefully identifying the issue, prepping the area, and methodically applying thin coats of joint compound creates durable, seamless repairs. With some practice, homeowners can easily restore their damaged drywalls. Addressing problems promptly keeps homes looking their best for many years.