What should you know about mix plaster of paris?

Plaster of Paris is a powder that becomes mouldable when combined with water. A trained clinician applies the wet layers around padding or a protective liner, shapes them to the body and allows them to set. The setting process creates heat, so the amount of water, handling time and layer thickness need professional control. The finished cast can hold a fracture still or maintain a corrected position during staged treatment. It is different from fibreglass in texture and handling, and the choice depends on the clinical task.

Do not mix or apply casting plaster at home. Keep a new cast uncovered while it sets and protect it from pressure, moisture and heat. Once the cast is firm, keep it dry and avoid pushing objects inside. Follow instructions about elevation, exposed-joint movement and weight-bearing. A cast may need a planned review because swelling can change the fit. In children receiving clubfoot casting, attend each scheduled appointment because gradual adjustment is part of the treatment plan.

Contact the clinical team urgently if the cast causes burning, escalating pain, numbness, tingling, unusual finger or toe colour, or difficulty moving exposed digits. Report a cast that becomes soaked, breaks, loosens, rubs the skin or develops an unpleasant smell. These changes can require a fit check or replacement.

Ask how long the cast needs to remain dry, which movements are allowed, when it should be checked, and how you will know it has fully set. If it is for a fracture, ask whether fracture casting is the complete plan and what would prompt a change.