How to Waterproof Tiled Showers
Here are our top five tips for waterproofing tiled showers. The Guinness Book of World Records tells us that 467 inches is the highest ever annual rainfall. However, a typical American shower floor receives over 2,500 inches of water each year, making this the wettest place on earth.
In addition, all of that water must be diverted to drains, to prevent it from penetrating the surrounding areas. This makes it clear that waterproofing is the most critical element of any tile contractors job. If the waterproofing is not durable or if it’s not installed correctly, that home or business could be devastated by water exposure and the resulting mold. Such failures create an expensive liability for the contractor and can cause serious health problems for the building occupants. So what is the best way for tile contractors to ensure waterproof shower?
1. Choose a Liquid-Applied Waterproofing Membrane
Unlike most waterproofing methods, a liquid applied elastomeric membrane creates a seamless barrier, that includes the drain assembly. The membrane provides thin, smooth and monolithic coverage over an area of any shape or size, in any configuration, in on horizontal, vertical and overhead surfaces.
Liquid membranes are typically ready to use and are fast and easy to apply, eliminating the hassle of measuring cutting and installing prefabricated sheets. The liquid is simply trialed, rolled or sprayed onto the substrate and allowed to dry. There’s no need to purchase corner pieces and waste is minimal. And if there is a space and a change of plane, no problem a mesh tape will help you bridge the gap.
Some liquids, such as Redguard waterproofing and crack prevention membrane, also provide high-performance crack isolation, exceeding both ANSI A118.10 and A118.12 standards. Red guard qualifies as an IAPMO pan liner and meets many rigorous building and plumbing codes. As a low perm vapour barrier, it is ideal for effectively managing moisture vapor, in steam rooms and gangue showers and again with no seams or fastener penetrations. Perhaps try a liquid solution with even faster curing. Redguard speed coat rapid curing waterproofing membrane. This special formula cures in about an hour, even in cold or damp conditions.
2. Ensure Proper Drainage
Regardless of size, the shower floor and the tile assembly, must be properly pitched to direct water to the drain. The Tile Counsel of North America recommends sloping mortar beds and showers at a quarter inch per foot to the drain as illustrated in TCNA B421. The waterproofing membrane is applied on the surface of the mortar bed, not under it. This method prevents the mortar bed and substrate from being saturated with water. If the membrane is applied under the mortar bed, first install a cement based pre-slope.
Always tie the liquid membrane into the drain by applying it to the bottom of the drain flange and clamping it in place. Then surround the drain with pea gravel or weep protector, to prevent mortar from blocking the weep holes. Position drain strainers so that they’re flush with the eventual tile surface, and not above it. Finally, assure that drain assemblies are well secured, so they don’t deflect and damage the membrane.
3. Prepare All Substrates Carefully
In addition to the quarter inch per foot pitch toward the drain, ensure that all horizontal surfaces, including seats and shelves, are sloped and smooth with no low spots or bird baths that could collect water. Standing water in a shower can lead to stained natural stone, premature failures, efflorescence and the growth of mold and mildew. Shower walls must be plumbed, squared and treated with a waterproofing membrane, all the way to the top of the area to be tiled.
Do not use drywall or green board in showers or even tub surrounds create a suitable substrate for tiled walls by using a waterproof cement backer board, such as wonderboard light. Prior to applying the membrane, ensure that all wall and floor surfaces are clean dry and structurally sound, as dust residues and other contaminants can prevent the membrane from achieving a proper bond.
4. Always Read and Follow The Product Instructions
Since the integrity of the waterproofing membrane is so critical, it’s very important to follow directions given by the manufacturer. Make sure that the membrane is applied at the specified coverage rate or thickness without any pinholes or voids. Ensure a continuous film and allow it to fully cure between coats. A fiberglass mesh tape should be embedded on the drain transition and may be needed for reinforcement that changes a plane or at plumbing protrusions. Protect the membrane following application, so it’s not punctured, soiled or damaged by other trades. And don’t neglect flood testing before installing the tile. If you need to repair an imperfection in the membrane, it’s much easier and less expensive before the tile is set and grouted.
5. Use a High-Performance Installation System
Showers are challenging areas. They call for high-performance materials. This is especially true when shower walls are being set with large format porcelain, natural stone or thin gauge porcelain tile. Given the size and weight of these materials and the wet conditions, use a mortar meeting ANSI A118.15T. When formulated for large format tile and stone, thixotropic mortars, such as customs mega light and pro light mortars, hold heavy tile and place on walls without sagging.
When a cement base grout is used in showers, it should be sealed after caring and resealed annually. Or choose a grout that doesn’t require sealing, such as fusion Pro, single component grout. For movement joints and changes a plane in the tile assembly, or for plumbing protrusions, use a color matched mildew resistant sealant.
If these steps seem alien or hard to follow, you can always contact the professional waterproofing agents in Johor.
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This is an aggregator article. The original is found on the Waterproofing Johor Website.