The Complete DIY Guide to Skim Coating Textured Walls

Outdated, damaged wall texture can make a room feel tired and dingy. While fully removing texture is an option, it creates a huge mess and requires re-drywalling the entire surface. For a fast, affordable way to smooth over textured walls, skim coating is the perfect DIY solution.

Skim coating involves applying a thin layer of joint compound or "drywall mud" over the existing wall texture. This conceals the bumps, peaks and imperfections to create a blank slate for painting or wallpaper.

With some basic tools, materials and technique, skim coating can transform the look of a room over a weekend.

There are several cases where skim coating shines as the ideal fix for textured walls:

• Concealing outdated popcorn or heavy knockdown texture
• Creating a smooth finish for painting or new wallpaper
• Masking uneven texture when doing wall repairs
• Covering painted texture that is impossible to remove

Skim coating provides a cost-effective way to rid walls of unsightly texture without the huge mess and tear-out of removing it. The thin mud layer smooths irregular bumps or peaks for flawless results.

Benefits Over Other Texture Removal Options

Compared to other options, skim coating has some clear advantages:

• More affordable than removing texture which requires new drywall
• Less messy than sanding or scraping texture
• Faster than adding new 1/4" drywall over existing walls
• Creates a pristine level 5 finish for any decor

While it takes a bit of patience and elbow grease, a DIY skim coat project yields professional-looking walls on a budget.

Skim Coat Materials Checklist

Skim coating requires just a few supplies, most of which are available at any hardware store:

• Drywall joint compound - pre-mixed all-purpose or lightweight formula
• Drywall knives and trowels in 6", 10" and 12" sizes
• Sandpaper and sanding blocks - 120 and 220 grit recommended
• Dust mask, drywall gloves, work clothes
• Low-odor drywall primer
• Paint roller, brushes and paint for the finish coat

Joint compound and applicator knives are the two essentials. Investing in high-quality tools helps make the job faster and achieve better results.

Preparing Textured Walls for Skim Coating

To ensure proper adhesion, the wall surface must be prepped before applying joint compound:

Cleaning and Degreasing

Use TSP cleaner and water to scrub away any grime. Rinse thoroughly. Degrease any areas around stoves or near kitchen ceilings.

Filling Cracks and Holes

Fill dents, cracks, or deep crevices with joint compound and let fully cure before skim coating.

Sanding Glossy Paint

For slick or glossy walls, sand lightly with 120 grit paper to help the mud adhere.

Mixing the Joint Compound

Joint compound (or drywall mud) is available pre-mixed or in powder form. Pre-mixed, all-purpose compound is the easiest to use for skim coating projects.

Thinning With Water

For a smooth consistency, thin batches with water up to 50%. Add slowly and mix thoroughly to avoid lumps.

Mixing Small Batches

Mix only what you can apply in 45 minutes before drying. Discard any hardened compound.

Applying the Skim Coat

Using a drywall trowel or knife, apply a tight, thin layer of joint compound across the textured surface:

Applying From the Top Down

Always start at the top and work downward to avoid lumps. Apply slight downward pressure with the knife.

Loading Thin, Even Layers

Spread a smooth, tight layer that conceals texture without changing surface level.

Working in Small Sections

In 2x2 ft. sections, apply compound edge-to-edge in overlapping rows, holding the knife at a 45deg angle.

Building Up Layers

For heavy texture, thin coats may require 2-3 passes. Allow proper drying time between layers.

Achieving a Smooth Finish

Proper technique ensures an even surface and avoids issues like trowel lines:

Maintaining a Wet Edge

Overlap compound into previously applied sections to blend the transition.

Feathering Out the Edges

Blend the skim coat seamlessly into surrounding texture without ridges or edges.

Filling Low Spots

Look for missed areas and fill low spots that could telegraph texture.

Drying and Sanding the Skim Coat

Allow 24 hours between coats. Before priming or painting, sand the skim coat layer:

Ensuring Joints Are Cured

Test dryness by scoring the surface with a knife. Dry compound won't leave a mark.

Pole Sanding Large Areas

For big walls, use a drywall pole sander with 150-220 grit paper.

Hand Sanding Small Areas

Finish inner corners or detail spots by hand sanding. Take care around edges.

Priming and Painting the Walls

A quality drywall primer helps paint adhere to the thin skim coat layer:

Applying Drywall Primer

Use a low-odor, water-based primer made specifically for prepared drywall.

Top Coating With Interior Paint

Apply desired interior paint finish and enjoy your beautiful new smooth walls.

Skim Coating Dos and Don'ts

Follow these tips to ensure skim coating success:

DO

• Prep surface thoroughly - clean, sand, fill holes
• Apply thin coats and build gradually
• Feather out edges for a seamless blend
• Allow proper drying time between coats

DON'T

• Overthin compound - leads to shrinkage
• Rush through coats - can telegraph texture
• Skim coat over unpainted drywall
• Spot-sand too aggressively - risks damage

Frequently Asked Questions

How many coats of skim coat are needed?

Expect to apply 2-3 thin coats for full texture coverage. Heavily textured walls may need additional coats.

Can I use lightweight spackle instead of joint compound?

Lightweight spackle dries faster but may require additional coats. Joint compound leaves an ultra smooth finish.

What grit sandpaper is best for skim coating?

Use 120 grit paper for the initial sanding, then 220 grit for final smoothing before priming.

How long does it take for skim coat mud to dry?

At 70degF and 40% humidity, compound dries in 8-24 hours. Cooler/damper conditions slow drying.

With some handy DIY skills and joint compound, you can breathe new life into rooms plagued by textured walls. The thin skim coat hides imperfections for a smooth, fresh finish primed for painting. Conquer outdated popcorn ceilings, heavy knockdown or uneven wall repairs.

It does take some patience - a single wall may require 2 days from start to finish. But the messy labor of removing texture is avoided, and the total cost is under $100.

Follow these tips to ensure your skim coating project checks all the boxes for an elegant, flawless finish. Take your time to master the techniques, and you'll be impressed by the dramatic transformation.