The Best Way to Remove Plaster from a Wall or Ceiling

*******

This post is a rework from an essay originally published with the title Ten Hammers. I left a bulk of it in the Outtake below (jump to it clicking that link). It featured a procedure I used with a friend to neatly remove a section of plaster from a ceiling. I think it has value, so please read on. And as always, I welcome constructive feedback on this technique in the Comments section at the bottom. Thanks. ~jb

Removing Plaster in Old Houses

Any old house owner that has removed plaster knows just how, well, miserable it can be. The amount of debris and waste it produces is simply shocking. In terms of demolition, the best case scenario – your plaster is only ⅜” thick. But from experience, I find instead that most plaster and wood lath surfaces are often easily twice as thick – around 3/4″.

The most common and flat-out brutish way to go about removing plaster: Whack the wall with the claw of a hammer, work in a long pry bar and have at it. Feeling tough, some might grab a sledge hammer. It’s a great way to take out some frustration and with it, removal seems to go twice as fast.

Plaster Removal Creates a Lot of Dust

Best practices – you’d set up dust containment and perhaps a means of negative pressure ventilation. At minimum, you could sit a box fan in a window and point it outward. Things get extremely dusty in this process.

Beyond that, maybe you’ve considered questions about the lead content in the plaster itself (and its dangers, especially when released in airborne form). Of course, that’s not to mention the paint that has been chosen to cover it through the years.

Feeling a little sly, you might grab a shingle remover and pry. In most cases, it doesn’t matter if you just scrape off the plaster and/or yank the lath right off while you’re at it. The plaster crumbles straight down to the ground – creating a heap and a fog.

As your pile of crumbled plaster starts to grow, and when it reaches about shin height, you pull out a snow or other shovel. You use it to transfer your pile of deconstructed plaster to a contractor bag. And after you’ve filled your third, you get the idea to just stab at the wall with that shovel.

As a helper removes the plaster from the room (boy, those bags are heavy), you finish exposing the framing below.

*Now, we’ve all done it – fast and dirty. Well, at least – dirty. And I’m sorry – there is a much better, or at least – a smarter, way.

Making Cut Outs in Plaster / Removing Plaster in Sections

The below procedure is designed for the case when you have access to the back side of the plaster. That is – as is the case with say a cutout for a set of attic pull down stairs and/or as I did with my kitchen’s passthrough. (Regrettably I did not take pictures at the time.)

When making a cut out, you are usually cutting into a stud or joist bay, tight to the inside edge of framing. Cut outs are usually required for smallish house modifications, but repeat this operation if you removing more of a surface, like an entire wall.

It requires two people (three is actually preferable), and note the resulting waste will be surprisingly heavy! So . . . SAFETY FIRST! Work gloves, a particulate respirator and eye protection are a must.

The Steps:

1) Mark Off your Desired Cut with a Pencil and a Straight Edge

2) Cut Scrap Framing Material to Make Cleats

Cut two pieces just short of the length of the desired cut out. We’ll call these pieces cleats. Then cut four pieces just short of the width of the cut out. Furring strips will do just fine for this operation.

3) Set up Cleats on the Back Side of the Surface (Wall or Ceiling)

With two people, one working on the back side of the plaster – hold the longer cleats about 4″ from the perimeter of the planned opening. (These cleats should run perpendicular to the lath.)

4) Screw Shorter Cleats through Plaster (and Lath) into Longer Cleats

With a solid point of reference (gained maybe from several pilot/probe holes driven through the plaster), agree upon a means of communication with your helper.

The second person, working from the front, holds the shorter cleats at regular intervals across the proposed opening. Working together, screw two 3 1/2 inch screws into each cleat intersection (four screws total per short cleat).

These screws go through the outside cleat, through the plaster and the lath, and into the cleat behind. (Trust me – this will not be easy, and there is some risk.) The person working on the back side of the surface will need to be conscious of their hand placement and communication throughout must be effective.

Optionally, and employing flat washers, add additional shorter screws on diagonals and around the perimeter of your cut out. These grab not the cleats but the only lath. Further, and to ensure that the plaster that is to remain, remains intact – set a handful of washered screws off the edge around this perimeter as well. With these washered screws, attempt to sink them into framing.

5) Preparing to Cut Out the Plaster

Note: We are going only for a rough cut, but with a little more precision, you could have made a full-blown jig for the cut out. We could build a full “ladder” – placing additional cleats on the front side, and still offsetting those on the backside. Use this then as a guide for the fence on your sawzall as you execute the cut.

Drill starter holes, approximately 1 ¼”, just inside each corner of the planned cut out.

6) Support the Plaster that is to be Removed

Optionally, take a sturdy rope, a 16-foot length (or longer), and attach it the back side of the assembly in some manner. Attach it at two points. Then, take the free end (the middle) of the rope and, if feasible, tie it off somewhere. Leave two to three feet of slack.

7) Cut Out the Plaster

Along the cut line, score with a utility knife first and make your cut with a reciprocating, or a mess-making circular, saw. Use a discardable bi-metal blade. Important! At each corner, stop about two inches short of connecting the cuts.

8) Remove the Plaster Section and Haul it Away

Have the person on the backside of the plaster come around to the front side. Give each uncut corner a couple of firm whacks with the hammer. Complete cuts by hand with a jab saw. Pry the lath away from the framing, supporting the plaster section. The helper quickly returns to their original location and unties the rope. They then use the rope to help lower the slab of now freed plaster and lath to the ground. The person on the outside of the cut, spots and guides the cut out.

*******

In doing this, and while it may seem excessive to some – you will keep the plaster and lath coupled – greatly minimizing dust and debris. It also makes the clean up process more efficient and less back breaking. You do need to be conscious of existing framing members (if they are to be saved). But it simply sets you up nicely to return later to complete whatever larger job you’ve intended – installing plumbing, installing a door, removing the wall, etc.

*******

Now if you are in fact removing an entire wall, just repeat. While it my seem slow at times, I think in the end you’ll find – it’s, at minimum, a wash and your job site remains more, well, orderly.

But what if I don’t have access to the back of the plaster … dude?

A similar technique can be transcribed to fully finished walls. Using some probing (with the claw of that hammer) locate studs. Take a ⅜” sheet of plywood (or OSB) and cut it to a reasonable size. I’ll say no more than 4×4 (again – the resulting waste will be heavy), but an odd size might work just as well. It can either be the exact size or just smaller than your planned cut.

Using washers, screw the plywood to the face of the wall. This screw pattern does not have to be exacting or even pretty. Screws just need to sufficiently grab lath. (Understanding how plaster walls are constructed can help greatly at this point.) An 8” screw spacing, in this case, will likely work very well.

Then working from the top of the wall down, execute your cut outs, strategically placing them in relation to framing. Still with two people, catch the plaster sections as you remove them. Heck, in this configuration,  you could even add handles to your ply – this make grabbing, carrying, and removal in general much easier on larger jobs.

Reuse your cleats, jigs and/or ply as you see fit.

*******

Outtake :: The Backstory

I have only spoken briefly about my last, last house – a 1920s cedar-shaked Colonial. It was a large hulking structure on a street filled with duplexes, I-houses, and bungalows. And that’s exactly what my neighbor, we’ll call him – Tom, had – a bungalow.

Tom and I are actually quite different. He is full-on craft brew, while I’m, you know – more Miller Lite. A smart, gritty, street-savvy entrepreneur, the owner of a local coffee establishment. He is in all ways representative of the DIY super-culture that exists here in Baltimore.

Tom didn’t call me over for my expertise that weekend; he had the matter well in hand. That day, he needed, well, another hand. He had been working on installing pull down attic stairs.

Like many bungalow owners with growing families, he was concerned about, and trying to access an underutilized portion of his house. With stairs, he’d be able to use a small bit of his third floor for storage.

The ceiling on his second floor was finished with plaster and lath. He had a very solid plan of attack for it. I would be his spotter. We started by protecting his refinished floors from falling debris. (I always recommend Ram Board for this operation.)

That day, he made some cuts and a smallish section of the ceiling (approx. 2 x 3) was removed almost perfectly to plan. I did my part; I eased the cut out, extending from the existing attic access, down to the covered floor.

When it was all done, it was heavy, hoppy micro-brew Time!

Ten Hammers – a Deconstruction

So as Tom and I hung for a bit, talking over a beer, I told him about my time working for a general contractor. He told me that his dad was a sheet metal contractor.

We laughed about my first experience with demoing plaster – just as it was detailed above. He told me he worked for a bit in set construction on stage crews.

Let’s be fair, too, and I will show my age, and expertise, I probably have as much experience with pneumatic tools as I do with a hammer. But I still know what one is. The first known iteration of an impact tool; it is used to drive things, like nails.

Does it take skill and focus to wield a hammer?

Yes, absolutely. I find that you (general) must focus dead set on your target, an extension of your hand, and becoming one with it, you deliver a blow.

Further, the hammer is a symbol of the worker, of the god, of the warrior, of the carpenter.

There are many different kinds of hammers, each with a design for its specific purpose. And you may have a favorite one for each of the myriad of construction-type tasks you must perform. (I always hear about Tom Silva‘s series of hammers, you know, with the wooden handle shopped to look like Swiss cheese.)

Question: Why don’t hardware stores or home centers give you a place for a good test drive of their hammers. A table where you could, I don’t know, bang some nails? …Liability?

Picking and using a hammer is all about feel. Sure, it’s OK to look for features, and to take your time when selecting. But hammers even in the same lines seem to be slightly different one to the next.

*******

For more essays from us, please see our Category = Essays. For more on Old Houses and Plaster, see our article – How to Repair a Large Crack in Plaster. ~jb