Limestrong Soap Finish

applying a limestrong soap finish to interior plaster

LIMESTRONG SOAP FINISH is a true castile olive oil soap for interior use over Limestrong finish plasters (Fine Finish and Interior Finish). A Limestrong Soap Finish is optional, but will give the plaster a silky feeling and increase the stain resistance and wipe-abilty of the plaster. Many feel a soap finish deepens the beauty and enriches the aesthetic of the plaster finish.

Packaging and Coverage. Limestrong Soap Finish is packaged as a concentrate in single quart containers—enough to mix with 2 gallons of water in a common 5-gallon bucket. Coverage per gallon of ready-to-apply soap finish is 300 to 400 square feet depending on finish plaster texture and porosity.

Tools and Materials. Soap finish is mixed in a clean 5-gallon bucket and applied with a roller. Use a clean roller frame and a new roller head with a quarter-inch nap. Also purchase a new in-bucket roller screen and a stir stick.


Allow plaster to cure completely. Leave protective tape and masking in place until after applying the soap finish.

STEP 1. In a clean bucket, dilute soap concentrate 8-parts water to 1-part soap.

STEP 2. Using a clean stir stick, mix gently to avoid excess foaming.

STEP 3. Apply the soap with a new or clean roller. Using a clean roller screen inside the bucket, dip the roller in the diluted soap solution and roll off any excess with the screen. Avoid dunking the roller head completely in the soap solution, as this will tend to cause more drips and runs during application. Best to return to the bucket often to reload the roller head rather than apply too heavily and having to fight runs and drips. Work to apply a consistent amount over the entire surface for each coat.

STEP 4. Starting at the bottom of the wall, roll the soap solution on in random, overlapping strokes, taking care to avoid creating linear stroke patterns and drips. Apply two coats of soap, one immediately after the other.