Showers that fail in any way - from minor shower screen leaks to major issues with faulty shower trays - cost everyone including trades, contractors, builders and eventually the home owner.

Water is wonderful stuff, indeed, a requirement for life itself. But when it penetrates into unwanted areas, it can be devastating. It takes a remarkably small leak in a shower recess to dampen surrounding timbers enough to cause considerable damage, quite often by encouraging termites as well as the more obvious rotting.

True costs involved with problem showers are hard to define, but every time a problem shower needs to be investigated it costs contractors time, money and possibly reputation.

The following lists highlight the common issues found with current designs and construction methods for fully tiled and enclosed showers.

Recessed into slab:

• Position - often the recess is placed in the wrong position and requires costly re-work. Even if the builder does manage to have the concreter or waterproofer alter the recess without being charged, the problem still creates construction time delays. The re-work is also often not completed correctly, this usually occurs when the contractor is not charging for the repair.
• Depth - the tiler cannot achieve the correct fall to waste if the recess is not deep enough. However, if it is too deep builders risk not meeting concrete thickness standards, which may expose steel work. Concreters also have problems creating a consistent depth across the recess.
• Shape and size - often corner angles are not accurate, recesses are not square to walls and/or the size of the recesses are too small or too big. Also there are usually rough edges that require cleaning up before waterproofing can be successfully applied.
• Cost - the cost of the recess not being itemised on the invoice does not mean that the concreter is installing it for free. Most concreters hate having to mark-out and box up the recess locations. There are also costs involved with repositioning, adjusting and cleaning up recesses that are usually worn by the waterproofer, but in the long run it does cost the builder (supervisors time etc)
• Issues with waterproofing around wall/recess junctions - this depends on how wall sheeting is installed. Sometimes the sheeting stops at floor level leaving a large gap to the bottom of the recess. Very often this is bridged by the water-proofer using plastic angle, creating more and more seams and joins in the shower area and vastly increasing the risk of a future leak.
• Issues with placement and use of thin standard angle waterstop - it is common to find no waterstop installed at all, which breaches the Australian Standard. Often the water-proofer has to install the angle 20mm or more from the edge of the recess to meet the required shower dimension. This creates serious problems for the Tiler trying to "fall" the tile towards the waste, over the top edge of the recess.
• Lack of a waterstop - many people incorrectly believe that concrete forms an adequate water barrier therefore many recesses don't have any type of waterstop fitted. Water actually migrates or wicks through concrete using capillary action.
• Issues with shower screen fitment - even if the waterstop angle has been correctly installed and protrudes 5mm above finished tile height, this type of construction is almost never watertight. Typically the screen is installed with a "H" section glued over the waterstop angle with silicone. Close examination reveals that the screen is actually sealed to the tiles and not to the angle, allowing the transmission of water through grout lines and glue cavities and out of the shower enclosure. In addition, with constant expansion and contraction caused by hot and cold water, the cavity inside the "H" section also acts as a pump and draws water out of the enclosure. In order for any shower design to succeed, there must be a positive, waterproof connection between the shower screen and the water-proofing membrane.
• Final inspection issues - it is impossible for builidng inspectors to know if the construction method was followed correctly because all major waterproofing components are covered by tiles.

Aerated cement/brick and tile hobs:

• Pieced together - relies on mitre joins and it is difficult to get the entire perimeter level. There are usually inaccurate 90 degree or 135 degree angles. The shape is often out of square leaving problems for tilers.
• Aerated cement requires sealing - it is common to find these installed unsealed especially if they are formed or altered on site.
• Does not isolate wet tray area from bathroom floor or walls.
• Inconsistent size and shape - Tilers frequently pack low points in hobs with thick layers of mortar outside of the membrane. This increases the likelihood of water 'wicking' up into hob through the mortar and often pops tiles in short time. (We know of one major builder who converted to mosaic tiles because they are easier to remove "when" the hob fails).
• Dangerous sharp corners and tripping hazards.
• Valuable floor space taken up with thickness of the hob.
• Time consuming and costly to build and tile the hob.
• Cost - while hebel may be low cost ($20-$25) tilers charge by lineal meter and commonly take between 1-1.5 hours to tile a standard hob (approximately $50-$80 per hob). Add to this the cost of investigating why so many showers constructed this way leak - regardless of who or what is at fault, significant amounts of money are wasted by the builder and contractors just identifying problems, not to mention the risk to a builders reputation.
• Screen is glued directly to tiles and not to the water-proofing membrane. Tile grout is porous and is not waterproof. "Sealing" the screen to the tiles allows water to wick through the grout and under the tiles where it travels through the glue cavity to escape the shower enclosure. We repeat, in order for any shower design to succeed, there must be a positive, waterproof connection between the shower screen and the water-proofing membrane, NOT between the screen and the tiles.
• Screen is often positioned incorrectly and does not comply with Australian Standards.
• Final inspection issues - it is impossible for builidng inspectors to know if the construction method was followed correctly because all major waterproofing components are covered by tiles.

Standard (proprietary) angle:

• Pieced together - relies on mitre joins and it is difficult to get the entire perimeter level. There are usually inaccurate 90 degree or 135 degree angles. The shape is often out of square leaving problems for tilers.
• Most angle used is too low - this makes it difficult for tilers to get fall to correct shower waste.
• Thin material used - often damaged by other contractors.
• Shortcuts - many reports of tilers flattening these thin angles and tiling over them to save time.
• Cost - while this system seems cheap to install, when the true costs are assessed including high rates of re-work during construction and rectification work required when problems occur, the cost in time and effort alone becomes excessive.
• Tile level inside to outside shower is critical to allow successful capping of the waterstop when left protruding above tile line (difficult for tilers to do given thin angle commonly used as waterstops... frequently find angle is installed out of level)
• Many shower screen suppliers either do not have or refuse to fit a 'capping' extrusion to fit over the protruding waterstop. Screen suppliers commonly request waterproofers to fit plastic angles as waterstops because they find plastic easier to cut off at tile height, meaning the screen is placed directly on the tiles over the waterstop. This effectively hides the fact the waterstop has been cut off and creates the above mentioned issue of the screen being "sealed" directly to the tiles and not the membrane. "Sealing" the screen to the tiles allows water to wick through the grout and under the tiles where it travels through the glue cavity to escape the shower enclosure. One more time..., in order for any shower design to succeed, there must be a positive, waterproof connection between the shower screen and the water-proofing membrane, NOT between the screen and the tiles.
• Sealing a 'capping' extrusion over the thin angle waterstop forms a pressure difference between the inside of the cavity and the outside air which creates a pressure pump that breaks down the silicon and fills the cavity with water. This "pump" can easily push enough water to flood across the 5mm waterstop and into the grout lines on the other side. Also, the continual expansion and contraction of the aluminium capping extrusion with every shower use eventually breaks down the silicon seal on the outside of the cap and provides a constant supply of water to dry floor substrates or timber frames.
• The latest revision of AS3740 is proposing that the capping only be sealed on the outside of the waterstop angle. The theory behind this is to allow any water trapped in the cavity to drain back into the shower enclosure. In reality, water is pushed by thermal expansion over the waterstop and into the grout lines on the other side where it is free to wick its' way through the notched channels in the glue under the tiles, to a destination potentially many metres from the shower.
• Impossible for certifiers to know if the correct construction method was followed correctly because all major waterproofing components are covered by tiles.

Many of the theories associated with waterproofing a shower enclosure can appear quite sound when viewed on paper. It is not until extensive testing is undertaken that  the causes of so many problems in this area are uncovered. It is not our intention to upset people, but many builders remain tight-lipped about problems they are experiencing and are honestly at a complete loss as to their cause. Some will try to "band-aid" the problem to get through the warranty period when the problem will be passed on to the hapless owner. Others end up cycling through contractors believing the problems are caused by faulty workmanship.

Testing these issues is extremely complex, time consuming and therefore expensive. Leak testing of suspect showers by water-proofing contractors usually involves plugging the waste with an inflatable bladder and filling the shower recess using a bucket of water obtained from another source (to rule out shower plumbing). Very often, a problem shower will hold water when tested in this manner. The water-proofer rightly informs the builder that the membrane is sound and heads off to  the next job.

The builder then calls the plumber who proceeds to pressure test the pipework and finds no leaks. Becoming increasingly frustrated, the builder calls out the only contractor left, the screen installer, who checks the installation, finds all of the silicon sealant intact and correctly applied and tells the builder all is well. Mr builder then heads for the scotch cabinet...

As we say in our advertising,  no matter how good your contractors are, most shower designs cause the problems.

After trying many, our preferred method involves using water of different temperatures dyed in different colours to identify the origin, and repeating the test again and again to completely rule out the effects of chance and other anomolies. Few builders or water-proofers have the time or resources to instigate these sorts of tests, but it was necessary to find the causes once and for all. Time and again, the "leaks" proved to be emanating from grout lines and glue cavities. Careful disassembly of the shower area showed water consistantly wicking through the grout lines in the shower and down to the gap between the membrane and the tiles. The effects of hot and cold water create a pressure pump which pushes the water along in this gap and eventually out of the shower area. Once this was known, it was easy to see that any contsruction method where the screen is "sealed" to the tiles is simply not going to work.

Waterstop Streamline is the only modern, aesthetically pleasing way to positively connect the shower screen to the membrane in a tiled shower.