Return to the Home Repair Forum | Post a Follow-Up

Skim coating an old plaster wall

Posted by shannon185 (My Page) on
Fri, Aug 29, 08 at 10:43

Its time for us to remodel our 1922 bathroom. The walls are lath and plaster, which is in relatively good condition except for a few hairline cracks. Over the plaster is a layer of "Keenes Cement" which is scored to look like subway tiles and is not in good shape.

We would like to smooth over the wall and remove the subway tile markings plus correct other chips and gouges in this wall. Also we need to repair the cracks in the walls.

How is the best way to fix the wall? We were thinking about taping the cracks and skim coating the wall with a lot of layers of joint compound and sanding it to a smooth finish.


Follow-Up Postings:

RE: Skim coating an old plaster wall

Pre-mixed drywall mud will just make a mess of the surface.

Durabond is not water soluble once set up, and as hard as the Keenes that is there.

It will NOT sand, so do a smooth job.

RE: Skim coating an old plaster wall

Thanks brickeyee for this information. I've found out from doing some kitchen repair with Keenes Cement that we do not have the touch to do a good smooth job. Is there any other material like Durabond we can use that can be sanded? What about Easysand 210?


RE: Skim coating an old plaster wall

You can use Easysand, but it often requires extra coats of primer and paint, especially if sanded heavily.

RE: Skim coating an old plaster wall

Use a 50/50 mix of plaster of paris and joint compound.

We've been slowly doing rooms in our 1890's house, and the results with this mix have been excellent. Did the first room 12 years ago and it still looks terrific.

RE: Skim coating an old plaster wall

You might try regular topping over the easy sand to achieve a harder finish surface.
So far the advice is well taken, there is a learning curve and the sooner you learn, the less you will need to sand.

RE: Skim coating an old plaster wall

"You might try regular topping over the easy sand to achieve a harder finish surface."

Easysand is softer than Durabond, but any pre-mix is even softer.

The plaster finish is usually a mixture of gaging plaster and lime putty.
Lime putty takes months to finally harden (it absorbs CO2 from the air).
Plaster harden way to quickly for good workability, even with a lot of retarder added.
The mixture of lime putty and plaster provides a good shot term hardness, and an even better long term result.

RE: Skim coating an old plaster wall

Veneer plaster is made for skim coating. Mix it with 90 minute compound mix -- 3 parts compound to 1 part plaster. Don't use plaster of paris as it will harden up so fast you'll end up throwing most of it away before you get it on the wall.

You can try the above suggested mix and/or work with the veneer plaster mix alone or experiment.

Use a large, wide trowel to smooth it on and make up your own "darby" with a 2 x 4 about 2' long and attempt your final smoothing with that, wait and then sand and then fill your dips again until you get a reasonably decent surface.

Try to work fast, working slowly and methodically will cause more errors and you will lose sight of the "big picture" and with this kind of work you want to focus on the whole wall -- the whole job and not just a line or a lump here or there.

Also, irregularities that you can't get rid of can be feathered out and a fool the eye effect can be achieved by spreading the lump or problem over a larger surface so as to remove focus on one problem area.

RE: Skim coating an old plaster wall

The best way to repair the cracks in the plaster is to use a plaster adhesive.

In order to repair the cracks permanently, you are going to have to ensure that the plaster is solidly attached to the lath behind it (if not, the crack just comes back).

Using a plaster adhesive is pretty simple to do yourself. You drill down to the lath with a masonry bit all along the crack, spray the holes with a conditioner, and then fill with your adhesive. After that, you temporarily clamp the plaster to the lath with screws and washers. Wait 24 hours, remove the screws and you are done! Your plaster is structurally reattached to the lath.

Here is a link that might be useful: Plaster Adhesive

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Home Repair Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here