Having finished its job in the Cape provinces, the rainy season is upon the northern provinces, and homeowners may find that their tiled balconies, decks or roof slabs have not been waterproofed correctly.
It is essential to carry out the correct background preparation and to waterproof exterior suspended areas before tiling commences, to prevent water seeping through the grout and adhesive into the substrate, and consequently into the levels below,” says Sharon Margon, technical adviser at TAL.
Water leaks or damage shown on the ceilings and walls of levels below a waterproofed and tiled balcony or terrace could be as a result of either the area not being waterproofed prior to tiling; that the waterproofing compound was incorrectly applied or damaged; or that the floor water outlet is not draining properly and is flooding the balcony.
Some tiles, particularly porous natural stone tiles, and even light-coloured ceramic tiles, may change colour when the tile installation is experiencing moisture ingress from the surface of the installation.
To determine the problem, Margon says it is best to consult a professional tiling contractor who’ll be able to establish if the problem is related to failed waterproofing or cracked grout. If the waterproofing system has failed, it’s recommended to remove the tiles and start the waterproofing and tiling process from scratch.
It is possible to waterproof and tile over existing tiles, provided the existing tiles are in good condition and firmly attached to the substrate. Make sure that the tiles are not cracked, loose or hollow sounding, and that the level of the current floor allows for a height increase, especially concerning door entrances.
It is possible to waterproof and tile over existing tiles, provided the existing tiles are in good condition and firmly attached to the substrate.
“Attend to the water damage as soon as possible as water leaks will cause damp patches on the ceilings of rooms below the installation and this leads to peeling paint and costly repairs,” she says.
Keep in mind that the tile installation is an aesthetic finish and doesn’t act as a complete moisture barrier.
Here are the steps to follow when waterproofing and tiling an area exposed to the elements:
Waterproofing
Waterproof the substrate with a waterproofing compound, such as an acrylic based liquid waterproofing system, readily available from tile and home improvement retailers.
You will need: A primer, waterproofing system, reinforcing membrane, block brush, roller and silicone sealant.
Step 1: Priming
– The substrate must be in good condition, clean and dry.
– Prime rough, porous surfaces with TAL floor primer and smooth, dense surfaces with a TAL floorkey slurry coat (one part TAL floorkey to two parts tile adhesive powder or 1.5 parts ordinary Portland cement, by volume).
– Paint the primer onto the surface using a block brush, and allow to dry completely before proceeding.
Step 2: Application
Make sure that the tiles are not cracked, loose or hollow sounding, and that the level of the current floor allows for a height increase, especially concerning door entrances.
– To allow for movement, apply a 10mm silicone bead in all internal corners and interfaces. Due care must be taken to ensure that the silicone bead is not flattened out. Allow the silicone to cure for approximately 12 to 24 hours.
– For the corner and interface applications, apply the first coat of TAL superflex1. Immediately bed the TAL superflex1 membrane, 200mm wide, into the wet TAL superlex1, ensuring that there are no wrinkles or air bubbles trapped beneath the membrane.
The membrane must be pushed into the corners, ensuring that the entire interface is covered with TAL superflex1 membrane. Apply a second coat of TAL superflex1 to completely saturate the membrane before the first coat dries.
– For the main area application, apply the first coat of TAL superflex1 over the clean, primed surface. Immediately bed the TAL superflex1 membrane into the wet TAL superflex1.
Ensure that there are no wrinkles or air bubbles trapped beneath the membrane and that the membrane is adhered to the substrate by rolling out the membrane with the roller in two different directions. Apply a heavy coat of TAL superflex1 over the membrane to completely saturate it before the first coat dries.
– Ensure that the main application overlaps the corner applications by at least 50mm.
– Allow the TAL superflex1 system to dry completely (at least three days, depending on ambient conditions) before commencing with tiling.
Keep in mind that the tile installation is an aesthetic finish and doesn’t act as a complete moisture barrier.
– Don’t start the waterproofing application if it is about to rain, as rain will dilute uncured TAL superflex1 and cause run-off. Protect the system from rain or water immersion for at least three days after application.
Tiling
Step 1: Tile selection
– Use slip-resistant and textured tiles when tiling an exposed and wet area. Avoid smooth and polished tiles. Remember that natural stone tiles require sealing after installation.
Step 2: Adhesive and grout system
– It is recommended to always use rapid or quick-setting adhesives as, due to the impervious nature of the waterproofed substrate, standard-setting adhesives will take longer to set.
– The adhesive and grout system has to accommodate thermal expansion and contraction in the installation to withstand temperature fluctuations and frost. The tile installation also has to be water resistant as it will be exposed to rain.
– Use a water-resistant, flexible adhesive and grout system to install the tiles. This system is achieved by mixing the adhesive and grout with a latex additive.
– When using a latex-based additive in the adhesive or grout mixture, it is important to use the full amount of additive as stipulated in the instructions on the packaging. The latex additive should be used as a total water replacement in the mix.
Do not dilute the latex-based additive with water as this will weaken the mix strength, and the adhesive and grout will not perform to their designed specifications in terms of enhanced flexibility and water resistance.
“Keep in mind that a latex-based additive improves the water resistance of the adhesive and grout, but doesn’t make the installation waterproof,” says Margon.
– Seal the grout and porous tiles after installation.
SOURCE: www.property24.com
