If you have drywall, then installing backer board before adding tiles is usually seen as a necessity. Backer board, often made of concrete, gives the wall an increased load-bearing capacity, meaning that you can add tiles, or other heavy objects to the backer board, and they are more likely to stay upright. It functions rather like the drywall itself, and gives you additional support for all kinds of materials. While installing backer board will never be a replacement for the lath systems used by professional tilers, if you need to give extra support to a wall, you can do it using the backer board.
Using with Tiles
Backer board was invented to be used with tiles, and it is still a great way of securing tiles and other fabrics to your wall. The inner walls of modern homes may not always be strong enough to hold up a full tile surface, as might be laid in a bathroom, and so adding a backer board greatly increases the chances of getting your tiles to hold in position for a long time.
Backer board can be ideal for supporting tiles in areas where the wall has been damaged, or in places where the wall is particularly old. Look for signs of crumbling, and have a builder assess the load which your wall will be able to bear. If you have any doubts at all about whether the wall can support the tiles alone, installing backer board will save you problems in the future.
Using with Underfloor Heating
Another way in which backer board can be very useful is in supporting floors after electric underfloor heating has been installed. These types of backer board are often made of polystyrene and fiberglass and are particularly tough and hard-wearing. The backer board is laid under the heating mat systems, and then covered with a layer of tile adhesive. The floor is then laid using tiles, with the backer boards supporting the extra weight of the heating mats underneath the floor.
Tile backer boards can be used with underfloor heating systems, and are preferable to XPS boards, which are much less able to bear weight, and can only be used in small areas. If you have a larger area to cover with the underfloor heating, then installing backer board is necessary to prevent the floor giving way.
Using After Damage
As backer boards are so lightweight, and yet are still able to support tiles and other heavyweights, this makes them ideal replacements for broken and damaged walls. If you have had to remove part of the wall in order to add electrical cables or do some plumbing, you can repair small holes by installing backer board. Obviously, this is not a suitable repair for load-bearing walls, but if you need to put kitchen cabinets or shower heads onto the wall, then adding a backer board is a good idea.