Is plaster of Paris waterproof?

Hi Bhavna, I came across your question regarding is Plaster of Paris water resistant and would like to answer it. No, PoP is not resistant to water. It is dry and porous. When it comes in contact with water, it soaks up the water. It is like a porous cloth when dried and will take in water that touches it.  If you wish to make the PoP water-resistant for outdoor use, you must fill in as many floor pores as possible. Let me tell you more about this below.

How to make Plaster of Paris Water Resistant?

You can use fillers like resin, wax and shellac to fill floor pores and reach a decent stage of resisting water. I want to tell you that it isn’t possible to create a flawless water-resistant PoP. This is because a bit of moisture will pass through the floor treatment. So, you’ll only be able to reach a certain level with the filling technique. 

This is all I have to share with you. I hope you now know is Plaster of Paris waterproof when set.

Plaster of Paris, often referred to as POP, is a white powdery chemical substance which is obtained from heating gypsum. But did you know where the name “Plaster of Paris” came from? From ancient times, plaster of Paris is named so because of the abundance of gypsum material found in the region of Paris. Now since you have asked for is plaster of paris waterproof, let me share the details with you. Short answer is No. Let me explain it in detail below.               

Is plaster of paris water resistant or waterproof?

As I have previously mentioned, the answer to this question is very simple, No. Plaster of Paris or POP is not a waterproof substance. It is originally a dry and powder-like substance and when it is kept uncovered and exposed to water, it will soak a considerable amount of water. 

Although some substances like wax can be used to make the plaster of Paris more water resistant by sticking to its natural properties, the plaster of Paris can never be completely water resistant. 

Plaster of Paris is mainly a construction material that is used in ceilings and as a protective layer in the walls so that the durability of the wall remains intact. It is also used in hospitals in fractured bones cases. The POP is so hard that when it becomes totally dry, it can not be broken easily and this hardening results in immobilising the limb thus helping the bones to heal faster. It also has a use as a moulding and casting agent for the decorative items.