On our tile wall, about 99% of the area is tile and the rest is grout. This particular ceramic tile has a glass-like finish that is completely non-absorptive. On the other hand, the grout (the one percent) is uncommonly thirsty and indiscriminate about its thirst.
But get this: Our tile is finished only on the top--its back and sides are red Mexican clay that has been baked in an oven and is as parched and thirsty as a desert lizard in July. A drop of water immediately disappears into this clay.
What does this mean? When we take a shower, water rolls off the tile and is sucked into the grout. The sides of the tile then begins to suck water away from the grout until the insides of the tile can get wet. (This is also called trickle-down, the effects of which are nearly impossible to measure.) So even after the shower is over and the walls are dry on the outside, some of the moisture remains trapped where it cannot be seen and from where it cannot easily evaporate and escape.
Over time this one percent provides the perfect breeding ground for ugly black mold, ruining things for the 99.
The best defense is to soak the grout with silicone sealer, an outrageously expensive substance that is difficult to apply to walls and especially to the ceiling, causing an unavoidable measure of waste. It seems that using a spray bottle and sponge may be the best approach. My Scottish side cannot help worry about the cost, but it must be done.
In any case, the one percent cannot be ignored. It has an insatiable appetite, consuming more than it possibly can use, and with no ability to control itself.
The Divot Method
6 years ago