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We have moved into an older house which needs re-wiring - the plaster is also in poor condition so a fair amount of plastering is going to be required over the next few months.

We are trying to save cash and I'm generally a "have a go at most things myself" sort of person. From looking at videos on YouTube plastering doesn't seem too difficult, doesn't require any particularly expensive equipment, and if I make a mess of it I can either sand it down or re-do it.

That said, a couple of people have recommended to me that a good plasterer can get a lot done quickly for not too much money, and that if I get it wrong bad things can happen (like the plaster blowing in a few months time because I've not mixed it properly). Is plastering a low-risk job that I can have a go at myself, or am I likely to waste time and cause myself problems later?

The house is brick masonry with a small lath and plaster internal wall (which contains several small holes). The problems include several large-ish (1m x 1m) areas of blown plaster, cracks, screw holes and a generally poor old finish.

user20127
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Justin
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3 Answers3

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If you have failing plaster and lathe interior walls, the process is a bit more complicated than just troweling on some new top coat plaster. The scratch coat, or first coat that bonds with "keys" through the lathe. When these keys fail or break off behind the lathe, portions of the plaster will become loose and often fall off the wall. The correct fix is to remove all the compromised material exposing the lathe and apply a new scratch coat creating new keys between and behind the lathes. After that coat cures, then the finish coat is applied. The materials used are completely different for each step. Although it is not a very difficult job, like anything else that is very visible, the quality of the bond and finish are important to the structural soundness and visual appeal.

True plastering is becoming a lost art in a world dominated by sheetrock. Plastering is one of those jobs that takes a long time and lots of practice to become proficient at. I certainly wouldn't discourage you from trying, but don't expect perfection on your first attempt. Even though the finish coat is what you see, pay special attention to the scratch coat as that is what holds the surface to the lathe. If the scratch coat fails, a perfect finish coat is worthless. If your project is fairly small, go for it, but if you are looking at a whole room or rooms, it might be worth your time to get an estimate from a pro. With all the time and money you will spend doing a large project yourself and suffering through the learning curve, you may decide your time is better spent on doing something else.

shirlock homes
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    +1 Even mudding joints of drywall is an art that professionals can do a high quality job in little time, while a DIYer will end up with lots of sanding and uneven joints. It's not impossible to learn, but with volunteer projects that I've done, they contract out the mudding to the pros while allowing volunteers to frame walls. – BMitch May 23 '14 at 13:33
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    Hey BMitch, I've been doing drywall mudding off and on for 20 years, I'm not bad, but I can't hold a candle to the subs I hire. It is an art form! – shirlock homes May 23 '14 at 20:06
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Plastering isn't difficult, but like most trades it is difficult to do it to a high standard until you've done it a lot.

Why not have a go?

What's the worst that can happen? You decide that you don't like your results and decide to pay a tradesman to do it - you're no worse off.

If you make a decent job of it, you've learned a new skill and saved yourself some cash.

John
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I've successfully patched plaster walls with drywall. It's a pain, but it can be done.

  1. Chip away the plaster to expose half a stud on either side of the hole.
  2. Cut your drywall patch for the hole.
  3. Check the depth. Usually the plaster coat will be thicker than the drywall by a good amount. You want the drywall to sit inside the plaster by about 1/8" of an inch or less. I've managed to shim out the studs with paint stir sticks to achieve the correct depth.
  4. Sand off the paint on the plaster edge of the hole -- about the width of the sanding block.
  5. Tape the joint.
  6. Skim coat the drywall, and feather the tape joins out to match the plaster. This means your patch will be ever so slightly thicker than the original plaster, but good feathering will make it indistinguishable.
  7. Sand, prime, and paint.

With drying times, this will take about 1/2 an hour a day for 3 or 4 days.

Alternatively, you can mount the drywall directly to the studs, and do a scratch coat to thicken it to the plaster depth. This takes a different compound, and will need a skim coat to finish it.

Chris Cudmore
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