What is Skim Coat Plastering?

Years ago houses were built with plaster walls that were typically hand troweled 3-coats thick, required a skilled plasterer, and took up to 30 days to cure before being ready for painting. They were slow and expensive to install, but extremely durable and beautiful.

Why did we ever stop using plaster you may ask. It’s simple. After WWII the baby boom caused America to need a lot of housing and quickly. The old ways of building were replaced with the assembly line which was implemented in places like Levittown, New York with stunning efficiency.

The need for quick, affordable housing butted heads with the artisan trade of plastering that required years of training, and even with that resulted in slow to be applied and even slower to cure plaster walls and ceilings. A new form of wall covering called “drywall” aptly names because unlike plaster it was applied dry became immediately popular with builders. Relatively unskilled laborers were needed to screw the drywall into place cutting production times down dramatically and opening up the labor pool massively to almost any able bodied man with a drill.

Unlike plaster which is traditionally made of slaked lime and san, drywall was made from gypsum sandwiched between layers of paper. The sheets are screwed onto the studs and the seams taped and bedded with more gypsum which is cured and ready for paint in just a couple days.

Initial Problems With Drywall

While the builders loved the speed of drywall the public felt a general unease with such a cheap and quick product even though they were clamoring for quick, affordable housing. The appearance is significantly different from a plaster wall and being that drywall is cheaper than plaster, houses made with drywall were seen (rightly so) as inferior to houses with plaster walls.

No homeowner wants to brag about the cost saving parts of their house or show them off to the Joneses next door. Drywall fell into that category and people began looking for options to dress up their drywall. One of the best ways was skim coat plastering.

What is Skim Coat Plastering?

Skim coat plastering is a hybrid of the old 3-coat plaster wall and the new world of drywall that provides the speed and ease of drywall while delivering some of the notable benefits and beauty of older plaster walls. A laborer hangs the drywall the same way as before and covers the seems with tape before a skilled plasterer comes through to apply a thin, 1/8″ thick layer of gypsum plaster overtop of the drywall.

The system results in the appearance of a high-end troweled plaster wall finish without the additional time and skill to build up the 2 bases coats of plaster. With skim coat plastering you also save the time and expense of needing to install wood or metal lath behind the plaster. The drywall serves as the lath.

The drywall used for skim coat plastering is slightly difference from traditional drywall in that it has a thicker paper facing on one side that has a very fine texture to it. Typically called “plasterboard” or “blueboard” because of the color paper used, it is almost indistinguishable from typical drywall. The thicker paper facing and texture provide a strong key for the veneer plaster to grab onto and prevents delamination.

Veneer plaster can be applied to regular drywall if plasterboard is not available but it requires application of a bonding agent first or you can use a modern plaster blend that I use have used for years which combines veneer plaster and joint compound to increase workability and bonding strength. You can watch the technique in the video below.

Advantages of Skim Coat Plaster

The biggest advantage is the cost when compared to traditional 3-coat plaster systems. You can get a skim coat plaster wall at prices between $3 to $5 per SF as opposed to a traditional plaster system that will run $11 to $15 per SF including labor and materials.

The appearance is almost identical and a good plasterer can accomplish almost any pattern or texture with skim coat plastering as they could with 3-coat plaster. Here are some of the other benefits that you’ll find for plaster over basic drywall.

• Stronger resistance to damage than drywall
• Faster curing time than 3-coat plaster
• Availability of various textures and patterns
• Lower price than 3-coat plaster
• More availability than 3-coat plaster

If you haven’t thought about using plaster to upgrade your current walls or maybe even in new construction you should definitely take a look at it because it is an option for almost any home.

Old houses in particular that have had their plaster walls removed can regain some of that historic character they are missing by skim coating their walls with plaster. Plaster creates a slightly imperfect surface that in my opinion shows the hand of the maker. It’s perfectly imperfect and that’s what makes it so beautiful. No wall is the same and it’s in that uniqueness that its beauty really shines through.