Written and maintained by CASRAI Editorial Board
Last updated
Not medical advice. This page gives general product information for clinic and supply staff and for patients and caregivers. Cast care instructions come from the treating clinician.
Short answer
A shower cover for a cast is a removable waterproof barrier that goes over the outside of a cast or splint so it stays dry while bathing. It is not the same thing as waterproof padding, which is a material the clinic chooses when the cast is applied. OrthoInfo (AAOS) and the Royal National Orthopaedic Hospital (NHS) both say the cast must be kept dry, and OrthoInfo adds that even a covered cast should never be submerged or held under running water.
Definition and scope
“Shower cover”, “cast cover” and “cast protector” describe the same kind of product: a sleeve, bag or shield that fits over a cast or splint and is taken off after the shower. It is sold separately from the cast. The American Academy of Orthopaedic Surgeons patient site OrthoInfo describes the options as “2 layers of plastic” or “waterproof shields” used “to keep your splint or cast dry while you shower or bathe.”
The reason is practical. OrthoInfo states that “moisture weakens plaster, and damp padding next to the skin can cause irritation.” It also notes that fiberglass is lighter and stronger than plaster, while plaster is less expensive. Which material a patient has, and whether it can tolerate any moisture, is a question for the treating clinician.
How a cover is used in practice
OrthoInfo and the Royal National Orthopaedic Hospital (RNOH) agree on the core point and differ in emphasis.
- OrthoInfo (AAOS): “It is essential to keep your cast dry.” Use two layers of plastic or purchase waterproof shields. Even if the cast is covered, do not submerge it (in a bathtub, sink or pool) or hold it under running water such as a faucet or hose. It also warns that “a small pinhole in the cast cover can cause the injury to get soaked.”
- Royal National Orthopaedic Hospital (NHS): patients are told to keep the cast dry at all times, and that “you can purchase specially designed waterproof covers to go over the cast for this purpose.” It adds that “you may need someone with you to achieve this safely,” and that a “strip wash” may be necessary if it is not possible to use the bath or shower safely.
Neither OrthoInfo nor RNOH gives a step-by-step wet-cast procedure here, so this page does not either.
OrthoInfo and RNOH side by side
| Point | OrthoInfo (AAOS) | RNOH (NHS) |
|---|---|---|
| Keep the cast dry | Yes, “essential” | Yes, “at all times” |
| Cover named | Two layers of plastic, or waterproof shields | Specially designed waterproof covers |
| Submerging or running water | Do not, even with a cover | No statement |
| Leak risk | A small pinhole can soak the injury | No statement |
| Safety and alternatives | No statement | Have someone with you if needed; a strip wash if a bath or shower is not safe |
Cast cover, waterproof padding and liner: where the product sits
Search terms such as “cast liner”, “waterproof cast padding” and “cast sock” are often mixed up with cover products. The useful distinction is position, not name.
Outside the cast: cover or protector
A cover goes over the finished cast and comes off afterwards. It is a barrier only; it does not change the cast itself.
Inside the cast: waterproof padding
OrthoInfo notes that “in some cases, special waterproof padding and cast material may be used.” That choice is made by the clinic when the cast is applied, not by the patient at home. Waterproof padding is therefore a clinical decision, and it is not a reason to skip asking the clinician how to bathe.
Names that vary
Product names such as cast liner and cast sock vary between sellers. Ask of any product: does this go over the cast, or is it part of the cast the clinician applies? Follow the clinician’s instruction for anything that sits against the skin.
Where it matters for clinics and supply decisions
The checklist below follows the OrthoInfo and RNOH guidance described above.
- Confirm the cast material and padding with the treating clinician. OrthoInfo says special waterproof padding and cast material are used in some cases, so a cover question starts with what is on the limb.
- Treat the cover as a barrier, not as waterproofing. OrthoInfo says not to submerge a covered cast or hold it under running water.
- Plan for a single failure point. A small pinhole can let water in, so a damaged cover is a reason to stop and ask the clinician.
- Include the safety conversation. RNOH notes that a helper may be needed and that a strip wash is an alternative when the bath or shower is not safe.
- Related supply reading. See the rent versus buy guide for home medical equipment, the sports medicine clinic supply checklist and the podiatry office supply checklist. For other bathroom-related equipment, see what a bedside commode is.
Common misunderstandings
“A waterproof cover means the cast can go under water.”
OrthoInfo says the opposite: even if the cast is covered, do not submerge it or hold it under running water.
“A cover and waterproof padding do the same job.”
They sit in different places. A cover is external and removable; waterproof padding is part of the cast and chosen by the clinic.
“Any plastic bag is the same as a purpose-made cover.”
OrthoInfo and RNOH word this differently. OrthoInfo accepts two layers of plastic or waterproof shields; RNOH names specially designed waterproof covers. Follow the instruction the patient was given.
“A small tear is fine.”
OrthoInfo warns that a small pinhole can soak the injury.
FAQ
What is a shower cover for a cast?
A removable waterproof sleeve, bag or shield that goes over the outside of a cast or splint to keep it dry while showering or bathing.
What is the difference between a cast cover and a cast liner?
A cover goes on the outside and comes off. Waterproof padding is a material used inside the cast, and OrthoInfo describes it as used in some cases when the cast is applied.
Is a cast sock waterproof?
Neither OrthoInfo nor RNOH describes cast socks as waterproof. Ask the treating clinician about anything worn against the skin under a cast.
Can I swim or soak with a covered cast?
OrthoInfo says not to submerge a cast, even if it is covered, and not to hold it under running water. Ask the treating clinician about swimming.
What if the cast gets wet?
Neither OrthoInfo nor RNOH sets out a procedure for a cast that has got wet. Contact the treating clinician for advice.
Sources
- OrthoInfo (American Academy of Orthopaedic Surgeons), Care of Casts and Splints, checked 2026-10-30.
- Royal National Orthopaedic Hospital NHS Trust, Instructions for patients in an arm cast, checked 2026-10-30.
