{"id":512,"date":"2013-03-08T00:42:54","date_gmt":"2013-03-08T00:42:54","guid":{"rendered":"http:\/\/bathursthandyman.ca\/?p=512"},"modified":"2013-03-08T00:42:54","modified_gmt":"2013-03-08T00:42:54","slug":"shower-benches-and-knee-wall-detail-prevent-leakage","status":"publish","type":"post","link":"https:\/\/buildingology.com\/?p=512","title":{"rendered":"Shower benches and knee walls: How to prevent water leakage"},"content":{"rendered":"
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Greatly detailed knee wall.\u00a0 There is an overhang, and a clear silicone drip edge created just under the lip.\u00a0 If you have trouble seeing it, that’s a good thing.<\/figcaption><\/figure>\n

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It is all too common that in showers, water leaks into the wall causing damage to the studs insulation and substrate holding the shower in place.\u00a0 This usually happens happens from a crack in the grout from where one shower wall meets another.\u00a0 The leakage that usually causes this type of damage is very often a small of water adding every day as you take a shower and occurs over the course of months, years and possibly decades.\u00a0\u00a0\u00a0 It can also happen between shower grout, but that usually occurs in older showers.\u00a0 Usually.\u00a0 But that will not be the focus of this article.<\/p>\n

Do not use grout in shower wall corners or under benches<\/h2>\n
\"Grout<\/a>
Grout cracks due to inability to accommodate movement.\u00a0 The crack is very small but it is enough to leak water in the walls.\u00a0 This small leak can swell the wood structure causing the crack to become larger, and more water would enter.\u00a0 Within a few months or years, a crack like this can soak the wood frame behind it to rot and cause mould.\u00a0 Fortunately I caught it soon after installation, and fixed the problem wit a bead of silicone on top in addition to the silicone drip edge (discussed later)<\/figcaption><\/figure>\n

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The issue with grout is not so much that it cracks, but that is has no accommodation for expansion movement like any masonry based product. Every concrete building has steel rebar to counteract the expansion forces.\u00a0 This has nothing to do with the way it was installed, it is just a characteristic of a home with a wood frame that moves with seasonal humidity fluctuations.\u00a0 Everything moves even to such a small degree as seen in the photo above.\u00a0 Look how small the horizontal crack is.\u00a0\u00a0 So during your installation, you must plan for this eventuality.\u00a0 You might think bah, that crack is tiny, whats the worry?\u00a0 I can tell you that it is big enough for water to enter, and that is all that matters.\u00a0 This scenario leading to failure is more common than you may think.\u00a0 The solution is\u00a0 twofold.\u00a0 Do not<\/span> install grout in the corners flush to the tile because grout is so strong in compression, it does not allow for as much movement as no grout.\u00a0 Those walls need the ability to move towards each other without the grout in the way.\u00a0 It is possible that the surrounding tiles crack or adjacent grout joints to fail because of having the grout there.\u00a0 The best solution is to put grout a small amount the corners, and not very deep.\u00a0 The intention would be that the grout provides a substrate for your silicone sealant on top.\u00a0 It helps provide continuity, but don’t expect it to stop water.<\/p>\n

So how is that problem addressed?<\/h2>\n

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It is actually quite simple and for those of you who have older showers, you can do this too. Just make sure your tiles are as clean as the day they were installed.\u00a0 You must have no soap scum on the surface or it wont work, so give it a good scrubbing.\u00a0 Just install thick dose of silicone sealant on top of that grout, and that should be the finished product.\u00a0 It is definitely most difficult to tool the silicone over natural stones like this one, and doesn’t provides the cleanest look.\u00a0 In this scenario the walls can move and the joint will not delaminate or crack as silicone can accommodate the movement.<\/p>\n

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This is not the cleanest look, but it give you less headaches in the future<\/figcaption><\/figure>\n

Just a note about the silicone:\u00a0 Quality tile stores sell acrylic sealant that closely matches the colours available.\u00a0 That is great, but the only issue is that acrylic sealants don’t accommodate movement as well, and have a much smaller service life especially in regards to mould.\u00a0 The mould will appear much quicker if it is in contact with a lot of water which looks disgusting.\u00a0 This is not “A” brand vs “B” brand, it is just the properties of the acrylic, additives included.\u00a0 Silicone is the best choice, however the palate is very limited to about five colours.\u00a0 My favourite silicone is “GE silicone II” sold almost everywhere, but it is more expensive at about $5-6 each.\u00a0 Two tubes should do an entire shower with some left over.\u00a0 If your shower or bathtub drains correctly, the silicone can last upwards of 20 years or more.<\/p>\n

Create a drip edge using silicone<\/h2>\n
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Creating a drip edge such as this one (its hard to see because the silicone is clear)\u00a0 allows the water to fall straight into the pan, as opposed to running down the wall<\/figcaption><\/figure>\n

In addition to putting silicone in the corners, applying a bead of silicone under the edge of the lip creates a drip edge that ensures that water doesn’t run down the wall, but instead falls straight into the pan.\u00a0 Don’t expect your contractor to do this unless you ask for it.\u00a0 Drip edges are vitally important for reducing water entry into a wall.\u00a0 Drip edges can also be created during the installation by cutting a thin line (saw blade thickness) on the underside of the tile where the lip is exposed.\u00a0 I don’t like this method as much, because in a shower setting,\u00a0 not everyone remembers to seal the tiles in the new crevasse that was created with the saw blade, which is hard to do.<\/p>\n

\"Buildingology<\/a><\/p>\n