Do I Have Drywall or Plaster? How Las Vegas Homeowners Can Tell
You have a hole in your wall. You call a drywall repair contractor and they ask: is it drywall or plaster? You pause. You have no idea. Before you guess, here is how to tell — and why it matters for the repair.
Not sure what you have? Call (725) 337-6885 and we will assess it for free.
Why It Matters in Las Vegas Homes
Las Vegas has a wide range of housing stock. Homes built before the late 1970s — particularly in older neighborhoods near downtown, North Las Vegas, and Henderson — commonly used lath-and-plaster construction. Homes built after that era switched almost entirely to drywall (also called gypsum board or sheetrock). Condos and apartment buildings from the 1960s and early 1970s often used a hybrid system called blueboard with a skim coat of plaster over it.
The reason the distinction matters: drywall repair and plaster repair use different materials, different techniques, and take different amounts of time to cure. A contractor who specializes in one may not do the other well. Knowing what you have before you book anyone saves you a frustrating callback.
The Knock Test
Knock on the wall with your knuckles in a few spots. Drywall produces a hollow sound, especially between studs. Plaster produces a harder, denser sound — less hollow, more solid. This is not a definitive test on its own, but it is a useful first indicator. A wall that sounds completely solid everywhere you knock is more likely plaster.
The Thumbtack Test
Press a thumbtack into the wall surface with your thumb. Drywall paper gives way with moderate thumb pressure — the tack will go in. Plaster is harder and denser; you will feel real resistance and may not be able to push the tack in at all with just your thumb. If the tack goes in easily, you likely have drywall.
Look at a Switch Plate or Outlet Box
Remove a switch plate cover or outlet cover and look at the wall edge around the electrical box. If you see a single layer of grayish or whitish material about half an inch thick, that is drywall. If you see multiple layers — a brown base coat, a gray or tan middle layer, and a hard white finish coat — that is traditional three-coat plaster over wood or metal lath. The total thickness of plaster walls is often three quarters of an inch or more.
You can also look for the lath underneath. Traditional lath-and-plaster uses strips of wood or metal mesh as the base. If you can see through the gap around the electrical box and notice horizontal wood strips or a metal mesh backing, you have lath-and-plaster.
What Damage Looks Like on Each Material
Drywall Damage Patterns
Drywall damage in Las Vegas homes typically shows up as nail pops, settlement cracks at window and door corners, water stains that cause paper delamination, and holes from doorknob impacts. The paper facing on drywall will bubble, peel, or discolor when water gets into it. If you tap a water-damaged area and it sounds even more hollow than normal, the core has likely softened.
Plaster Damage Patterns
Plaster damage looks different. Older plaster tends to crack in map-like patterns (called alligatoring or crazing) as the material ages and the base coat separates from the lath. You may also see areas where the plaster sounds hollow when tapped — this means the plaster has separated from its backing and is now floating. These hollow spots, called blown plaster, can fall suddenly if left unrepaired.
Drywall vs Plaster: Quick Comparison
| Feature | Drywall | Plaster |
|---|---|---|
| Common in Las Vegas homes built | After late 1970s | Before late 1970s |
| Thickness | Half inch (typical) | Three quarters inch or more |
| Knock sound | Hollow between studs | Dense, solid |
| Thumbtack test | Goes in with thumb pressure | Strong resistance |
| Layers visible at outlet | Single layer | Multiple layers |
| Common cracks | Corner cracks, nail pops | Map cracks, blown spots |
| Repair time | Faster (same-day for small repairs) | Longer (multiple coats, cure time) |
The Hybrid: Blueboard with Skim Coat
Some Las Vegas homes and condos from the 1960s and 1970s used a system called blueboard with veneer plaster. Blueboard is a type of drywall with a blue paper face that accepts a thin plaster skim coat. The skim coat is usually one eighth to one quarter inch thick.
From the outside, blueboard with skim coat can look like either drywall or full plaster depending on the finish coat. At an outlet edge it will look like drywall (single layer) but the surface will feel harder and denser than standard drywall. The crack patterns on skim coat also tend to look more like plaster — fine map cracks rather than the corner-focused cracks you see on standard drywall.
Patching a skim coat wall requires matching the hard plaster finish over the patch, not just painting over joint compound. Many drywall contractors do not work with skim coat finishes, so mentioning this before you book is important.
Common Questions About Drywall vs Plaster
Can you repair plaster with drywall compound?
For very small surface cracks, joint compound can work as a temporary cosmetic fix. But it does not bond to plaster the way proper plaster patching materials do. Over time, a joint compound patch on plaster will crack and pull away, especially with Las Vegas’s temperature swings between winter nights and summer afternoons. A proper plaster repair uses bonding agent and setting-type compound or actual patching plaster.
Should I replace plaster with drywall?
Sometimes. If large sections of plaster are blown (separated from the lath) and the walls have widespread map cracking, replacing the plaster with drywall may be more cost-effective than patching each section. This is a bigger project that involves demolition and disposal of the plaster, then hanging and finishing new drywall. Get estimates for both approaches before deciding.
Does plaster contain asbestos?
Plaster itself is unlikely to contain asbestos, but some older texture coatings and joint compounds applied over plaster walls before the mid-1970s may have contained asbestos. If you are working on a Las Vegas home built before 1980 and plan to sand or disturb the surface, have a sample tested before grinding into it. The Las Vegas area has licensed asbestos testing companies that can provide a report within a few days.
How much more does plaster repair cost than drywall repair?
Plaster repairs typically cost more than comparable drywall repairs because they require more labor time, specialty materials, and more cure time between coats. Exact pricing depends on the size and location of the damage. We can give you a written estimate on either material. Call (725) 337-6885.
Ready to get your wall assessed and repaired? Call (725) 337-6885 for a free written estimate. We work with both drywall and plaster in Las Vegas homes.
Related: Drywall Hole Repair Las Vegas | Drywall Crack Repair Las Vegas | Texture Matching Las Vegas