Why not just use impervious grout and skip tanking?

[Andrew]

Hi,

Here’s a question (based on the facts that I am debating whether to WB1 tank a domestic shower above a bath for the first time, and that I understand that “waterproof” adhesives and grout only mean they will not break down and NOT that they will stop water passing through):

Why not skip the stupidly expensive BAL tanking system and just use an impervious grout (ie easypoxy) instead?

My products of choice thus far have been either white star / single-part flex, and microflex grout, onto a APD primed (but not waterproofed) area. Served me okay before, I must admit, but now I’m intrigued by this whole issue of a suitably primed plaster background, with plenty of waterproof tile adhesive, glazed tiles, and waterproof grout, and domestic setting only still not being enough to stop the rushing tsunami of water which will melt my walls and cause everything to fail

In all seriousness, comments appreciated.

[royaloakcarpentry]

I quite often add on to my posts that we rip out plenty of bathrooms each year that have been in use for at least 20 years on some of the developments we get work out of. All of them are tile onto plasterboard. They follow two distinct routes:

Good maintenance, silicone replaced periodically and all joints well applied. Immaculate plasterboard when we rip out.

Poor maintenance. Normally the bottom of the plasterboard is shagged and tiles blown.

We have ripped out bathrooms where MDF has been used as the substrate for tiling, hardboard, OSB, tile. Good maintenance and it has all been completely dry. Infact the MDF proved a fecking nightmare to get the tiles off.

We have ripped out bathrooms with supposed useless tiling backgrounds such as MDF where maintenance was non existant and the tiling backgrounds were completely shagged.

We have ripped out bathrooms that have tanked walls, the tiles have blown and the water just finds a route down and rots the floor, seeps through to the concrete slab and tracks along causing damage in other rooms.

We have an insurance price in at the moment for 40K. Large 2 bed flat that has had to be gutted.

This important factor is something either not known to a lot of people or just never advised on here. Tanking systems also have a weight limit of what they can support. That weight limit may be more than the substrate it is being applied to.




My stance on tanking is that there are situations where it is best practice to do it and the extent of it in that situation depends on the bathroom/shower room/wet room layout.

Am I using it for a wet room.......too right. Even with fully vitrified porcy tiles and epoxy grout.

Am I using it round a bath with a handheld shower on slide rail. No.

The biggest factor in the longevity of a bathroom etc (in my experience of doing them and ripping hundreds out) is the workmanship coupled with suitable materials and on going maintenance.

Re-wind back a good few years. Why weren't bathrooms and shower areas only lasting a couple of years before everyone and their dog went 'tank crazy'!

[N8rbos]

Fully agree with your comment there royal, the most problems i,ve come across are due to maintainence or lack of. It amazes me how much folk care for their cars compared to their houses.

[Andrew]

You might have just tipped me over with those comments. You are right, plenty of places are fine without it.

And I work to a good standard so it will not just be thrown in.

You didn't answer my question, but you also kind of have answered my question, so all is good.

[royaloakcarpentry]

Aah second part of question............white star adhesive I would only use in a bathroom with good ventilation and not with an over bath shower. I always use cement based in bathrooms, personally.

Water proof adhesives and grouts. Excusing epoxy. They are normally classed as waterproof if they do not fail after the average shower time.

Marketing and advertising is very clever..........International yacht Varnish, small print on the tin, not for use in wet areas!!