Siniat Watershield is a wet area plasterboard made from a core of gypsum sandwiched and lined with recycled blue paper. Watershield is commonly used as a water-resistant wall and ceiling plasterboard lining and as a substrate for tiles in internal wet areas such as bathrooms, showers, toilets and laundries.

Watershield may also be used as the wall lining for indoor swimming pools provided a waterproof membrane is applied over the wall.