Damp, mould and mildew are the eternal nemeses of any bathroom, and no part of your bathroom is more vulnerable to the deleterious effects of excessive moisture than your shower ceiling. Showers produce large amounts of airborne moisture which can quickly leave an unsuitable shower ceiling damp and mouldy—to make matters worse, shower stalls, shower curtains and splash guards all act as barriers to contain this moisture and reduce air circulation.
As such, a new shower ceiling should be made from materials that do not absorb moisture and do not allow for the accumulation of mould and mildew. Luckily there are a wide range of suitable materials, so you should be able to find the right material for your bathroom's particular needs.
When well fitted and properly grouted and backed with a suitable waterproof substrate a tiled ceiling can provide an extremely effective vapour barrier, protecting your ceiling from accumulating moisture. Tiles are also practically immune to mould and mildew. With bathroom tiles available in a wide range of designs and shapes, and made from a wide range of materials from inexpensive and durable epoxy to luxurious granite and marble, you can rest assured that you will find the right tiling for your overall bathroom aesthetic.
However, while tiling floors and walls can be done yourself with the right tools and knowhow, tiling ceilings is a difficult and awkward endeavour requiring specialised equipment, and you would be well advised to call in a professional tiling firm to tile your shower ceiling. Improperly laid tiles lose their waterproof properties and can be dangerous if they fall. Tiled ceilings will also require regular cleaning and occasional maintenance to prevent the accumulation of dirt and mould in the grouting between the tiles. Make sure any tile you purchase is glazed, as some unglazed tiles (such as terracotta tiles) are too porous for shower ceilings.
When it comes to general ceiling building cement board has been largely supplanted by lighter, cheaper drywall, but this venerable material still has a place in many shower ceilings. Cement board absorbs very little moisture, and its porous nature allows for rapid drying and excellent air circulation to discourage mould growth and displace spores. While a small amount of moist air is allowed to pass through cement board, many cement board suppliers provide a waterproof adhesive substrate to be fitted over the cement board; this provides a vapour barrier to protect the floorboards or roof timbers above.
Unfortunately, cement board is about as heavy as you'd expect something called cement board to be. It also requires special tools to cut, so like tiles your best bet is to go for a professional installation. Bare cement board is also far from the most aesthetically pleasing material, although it can be covered with relative ease.
A cheap, easy and surprisingly effective way to protect a shower ceiling from damp, plastic ceiling panels are generally made from PVC or uPVC, and slot together in a similar manner to easy-lay floorboards. They can be installed over existing ceiling materials, including textured plasters, and only require a simple adhesive to be fixed in place (although they can be stapled or screwed in place to provide additional support). If fitted properly, plastic panels do not require a waterproof substrate to provide a vapour barrier, and their smooth inorganic surfaces are thoroughly resistant to mould.
However, plastic panelling is neither the most aesthetically pleasing or the most versatile material, and will certainly look out of place in luxury or rustic bathrooms. As a relatively new addition to the bathroom ceiling market, plastic panels can also be difficult to find, and are available in a limited range of designs.