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Sustain Blog

Soap? On WALLS?

By September 5, 2018 December 4th, 2019 No Comments

Soap? On WALLS?

Yes, and not to clean them off.

Since we are a wall plaster installer, we use soap all the time to add to the beautiful effect that bare plaster has. If you recall in the post before this one, in order to properly Tadelakt a wall, the lime plaster has to have a layer of soap troweled on to it in order to give it it’s shine and water-proof capabilities. This addition is required to give Tadelakt it’s proper utility, but it can be added to any plasters that coat your walls for improved design characteristics as well.

The soap we are talking about here is not your everyday hand soap or dish soap which contains added fragrances and foaming agents. The proper soap must be used in order to not ruin the finish of the plaster. In this case, we use either olive oil soap or “black” soap. Both varieties are olive oil based and contain no added fragrances, foaming agents, or alcohols. And they both can still clean your hands! The main difference between regular olive oil soap and black soap is that the “black” part of black soap refers to added black volcanic ash. Only black soap can be used in Tadelakt because the ash is what creates the chemical reaction with the lime plaster that creates a water-proof surface. But that is not to say that it can’t be used with other plasters.

While adding soap to bare, non-lime plasters can give it a certain degree of waterproofing, it is mainly used to add a sheen to the finished product. Many bare plasters absorb moisture really well. This is a defining characteristic of our most requested plaster, American Clay. When adding soap to bare American Clay, the clay quickly absorbs the moisture in the soap. Included in this absorption is the oils also present in the soap. And once dry, the oils in the soap add a degree of waterproofing while enhancing the clay with a very slick shine. This helps to smooth out the clay and also enhance the “motion” of the installed clay. In these terms, “motion” refers to the subtle textures left behind after installing. These can include soft trowel marks, impressions, and other textures that are indicative of plasters installed by hand. In our opinion, adding soap to a bare plaster wall is a fantastic way to not only add to the strength and impermeability of the plaster, but it also provides a pleasing shine to it that brings out the characteristics that are unique to your walls! For more information, check us out on Facebook, Instagram, Houzz, or stop by our showroom to see and feel what a soap-finished wall is really like!

Detail of bare clay plaster, pre-soap.

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