hi, can anyone explain to me what is the point of tanking?
assuming you use correct addy, grout and mastic, how will any water get behind the tiles?
and surely if it does your tiles are in trouble? am i missing the point?
confused of carshalton

Hi Confused

Quite simply tanking will totally ensure that your shower wont leak water into the rooms below !
you can readsome of the posts here - all adhesives are not the same. Whilst they claim to be waterproof or water resistant that only means they will not break down and dissolve in water- it does not mean they provide a waterproof barrier to prevent water passing through them hence the need for tanking. Grouts are the same.

Tile grout is water resistant not waterproof (unless you use epoxy) the same goes for adhesive.
In a normal light duty shower area you will probably have no problems with the tiles but when it comes to heavy duty shower use ie, big families using the shower.
Then you start to have problems, the water will not have time to dry and it will work its way through the grout and to the adhesive where it will have no where to go except the surface to which the tiles were originally fixed. If it is plasterboard then it will become wet and the board will break down.
Tanking the walls will provide a waterproof barrier that will stop water getting to the boards.
IMO tanking is not necessary on low use domestic showers. As long as good quality adhesive is used which is suitable for the job such as Bal White star and grouted with suitable grout then all will be fine.
Depending on the tiles being fixed you may want to use a bagged adhesive if fixing larger formats. I know a lot of tilers here only use bagged adhesives but thats down to personal preferences.

thanks for your replies!...interesting reading.
I have been using keraquick/keraflex lately, would this be one that requires tanking then? what about straight on to hardibacker in a shower, lets say heavy use to be on the safe side.
Is there an adhesive and a grout that would not require tanking? you mentioned epoxy, is this user friendly?
ps if you have water behind the tiles, surely they will fall off eventually?
thanks in advance
slightly less confused of carshalton

My answer is Tank it and be safe rather than sorry. Even if a shower is low use with one family Imagine they sell the house and it become high use. For what a bucket of tanking costs it's worth it every time and its a good add on moneywise for the tiler.

I used to have a dozen tiles fixed to a sheet of clear perspex in my van. Run it under a slow house tap and show the client the water working its way through the grout. It sold the tanking every single time

Kev

I regularly do insurance jobs and nine out of ten of those are water damage in showers. I would say half are due to poor grouting or tiling the other half are settlement related. Anyway by the time the customer noticed the water in the next room or staining on the ceiling below the shower walls where well and truly knackered. Tanking would have stopped this damage to the walls and reduced my time & cost to retile. Tanking wont stop the water getting in if there is settlement and cracking of grout and addy but it sure makes the problem easier to resolve!

as cliff anger says,

its abouts about damage limitation to other rooms and not just the tiling aspect of things.

as a plasterer i have made a lot of money via insurance claims going out to properties and replacing ceilings due to water damage. tanking is actually a plastering process which was brought about in cellars below ground level were damp was rife so why not tanking?? its a proven watertight system and can make you more money on top of your tiling and give the customer extra reassurance and peace of mind, surely thats what a pro tiler should be recommending to his/her customers, unless they dont understand it or arnt up to installing it??

Also just to add to this...you can use tanking membranes as well...........a lot quicker and easier than solution kits.......

in response, as a professional tiler specialising in domestic work, i want to guarantee my customers that their shower enclosure wont leak, not that if or when it does there is damage limitation in place!
this is the point i have been driving at and no-one so far has convinced me otherwise!
if epoxy grout stops this, why not just use it?
also hardibacker boards are waterproof anyway.
ps i dont want to "sell" tanking i want to do the best tiling job possible.
i am happy to put the stuff on, god knows its not rocket science, i am just uncomfortable with the thought of water behind my tiles!
best regards, adam

The reason why we all do tanking is because of water reaching the substrate. Tiles can be proous with ceramic being 40% porous and natural stone being 60% porous. Grout can also be porous.

Customers expect a lot from their showers and bathrooms and sometimes do not matain them correctly. The number one failure in new houses is bathroom area!!

Just think what a power shower does to grout lines after time!

Ok brief run down:

Water and plasterboard = mush
Water and chipboard/plywood = warping and popping tiles

There are two breeds of substrate:

Water resitstant and Waterproof

Obvioulsy you have water resistant plasterboard but it can still break down in contact with water and if you read the literature it says light use only.

When you have Backer boards i.e. water resistant these are boards that can absorb water and control release it back into the atmosphere however these boards do not "warp, swell./ Crack etc"

Waterproof means the water will not penertrate the substrate.

There are plus sides and downsides of all of these. The main thing is where are you at and what condition will your bathroom been in when you start. I.e. have you already had plasterboard installed? Then go for a tanking system!

Hope this helps

Just remember some prevention is cheaper than no prevention!

hi northern bird
where can i get all the info i need on backerboards ie sizes, types, how to install, tech spec etc
ross

Originally Posted by Unregistered

in response, as a professional tiler specialising in domestic work, i want to guarantee my customers that their shower enclosure wont leak, not that if or when it does there is damage limitation in place!
this is the point i have been driving at and no-one so far has convinced me otherwise!
if epoxy grout stops this, why not just use it?
also hardibacker boards are waterproof anyway.
ps i dont want to "sell" tanking i want to do the best tiling job possible.
i am happy to put the stuff on, god knows its not rocket science, i am just uncomfortable with the thought of water behind my tiles!
best regards, adam

If you use cement based adhesives then it will with stand as much water as you can throw at it .. so to speak...after all swimming pools are tiled in it and are immersed in water for very long times.......if the correct adhesives are used then water will not affect them..it's the substrate that needs protecting from constant wetting.......not the adhesives or grouts........if correct ones are used.....

what i would like to add about tanking is that its a very easy process that seems to confuse a lot of people and some of the prices that some people charge dont reflect the cost/labour ratio. i have heard of some people charging upto 250-300 to tank a shower area and that is blatantly ripping the customer off in my opinion. everything has its price!

ross,

try..... www.backerboard.co.uk and www.aquapanel.co.uk

hope this helps

ed

I usually charge for the tanking kit and fit it for free. As Ed said - it's easy to install and one tanking kit will do about 3 or 4 bathrooms.

Waterproofing is mandatory over here, but since customers generally want to get away as cheap as possible with materials, I charge labour in relation to application time and drying time.

New regs say waterproof membrane or waterproof substrate with sealed joints for domestic bathrooms, but until the 1st of July, you can get away with using the older, cheaper, roll on systems. [Sidenote: over here, the whole bathroom is tanked, not just around the shower and bath tub]

I discourage that by charging more labour for those, as most of them take almost a day to dry (especially the cheap ones), and I still need to get paid for the entire day you know.

The membrane systems are faster to apply, and dry alot faster.
Thus, I can usually begin to tile the same day I apply them, saving me time and allowing me to do more work in shorter time. There is little or no cost increase for the customer, even though the materials are much more expensive (about 30%). The end product is also better and more durable, which is good for business.

I use the same approach when leveling. I don't use cheap crap which dries 1-2mm per day; I use high quality gear which is tileable the same day, or the day after if it's in a bathroom. This approach allows me to focus on one job at a time, and that saves me stress, and gains me more money, as I have more chargeable time than I would otherwise.

those web sites are excellent, just found www.wedi.co.uk and theres loads of info on you tube if you type in wedi....got all the info about fixing today from that but it mainly echoed whats been said on here, really interesting stuff
thanks,ross

Tanking is an essential part of a bathroom installation whether its for a shower, general bathroom or wetroom. Todays buildings being made like boxes that will turn to mush if you add water have seen to the importance of tanking.

In Europe its law and its on its way over here, if your honest who in his right mind would have accidental spillage of water over an electrical socket no one yet people happily put showers, wetrooms, free standing baths over kitchens etc. with no waterproof membrane.


If your doing a bathroom then tank the floor it litteraly takes an hour to do a good job and you know its safe, walls around. A bath shower can be done but go to the floor costs a few pennies more and its a solid job. Showers/wetrooms need the walls tanking 200/500mm outside the shower area and the floor below so say 5m2.

There are a few waterproof membranes to be had which are made for the job.

Membranes vary :

Tilebacker boards are ok but are generally more expensive than a really good membrane. Tilebacker (Wedi) 5m2 £140 + tapes

Paint on membrane (mapeigum) is there to be used but due to thickness variations when applying working conditions and differing ideas on how it should be used its not the most consistant of products. 5m2 coverage £35/45 + tapes

Tanking mat durabase is a system on a roll which is stuck to the walls with flexible adhesive so no paint brushes and seperate tubs required. Put it on like wall paper and it is an actual barrier between tiles and substrate. 5m2 £55

Tilesafe, the market leader pays for all its advertising by charging £175 for a 5m2 kit but like all others it has its place.



As a solution that is consistant and proven then Durabase or Kerdi ( no drying time, waterproof absolute) are the solutions the pro's should be using as they are the the undoubted way that this sector is going to go........ a sheet membrane system.



Not being unfair to any we sell them all at www.wetdecs.co.uk, if they arnt on the site then a simple email or call will get it sorted.

Hope this helps out a little

tiler

..

Let me put it like this:

In Sweden, it's been law to waterproof entire bathrooms and such, since the eighties. The standards have developed, and the rules have become more and more stringent. For about 13 years, roll on kits and joint tapes have been standard, but it's not enough it seems, because the insurance co's still pay up to the equivialent of £10m every week for water damaged properties, and that's in a country of about 9m people. Granted, the water damage claims are nothing now compared to what they were, but it's still a helluvalot of money.

No reflextion on the fixers then lol


..

Of course there's alot of cheating and skimping, but that's only part of the problem. I'm not entirely sure what the english terminology is here, but the main causes of damage, in no particular order, are:

• Faulty installation of the waterproofing
• Insufficient vapor diffusion resistance in the waterproofing
• Insufficient waterproofing of punctures in the waterproofing made during or after fixing of tiles or sanitary wares
• Faulty installation of plumbing resulting in failiure and water leaks, often for an extended period of time

The first, third and fourth points are being addressed with increased training, and greater demands on tilers/plumbers who wish to qualify for a wetroom license (domestic bathrooms are classified as wetrooms over here), or a plumbing licence. The waterproofing/plumbing systems are also being modified accordingly.

The second point is being addressed through increased demands on the waterproofing manufacturers. Waterproofing needs to be both water and vapor diffusion proof now. This excludes almost all roll on systems, unless they used in combination with water and vapor diffusion proof membranes. The reason for this is that the water vapor which does get through the waterproofing, even very little, is likely to cause mold growth.

The use of gypsum based board materials isn't permitted in bathrooms any more. The use of wood based substrates has been prohibited for many years.

The materials needed to waterproof an average bathroom today, costs in the region of £400-500, compared to £200-300 just six months ago.

Originally Posted by Unregistered

in response, as a professional tiler specialising in domestic work, i want to guarantee my customers that their shower enclosure wont leak, not that if or when it does there is damage limitation in place!
this is the point i have been driving at and no-one so far has convinced me otherwise!
if epoxy grout stops this, why not just use it?
also hardibacker boards are waterproof anyway.
ps i dont want to "sell" tanking i want to do the best tiling job possible.
i am happy to put the stuff on, god knows its not rocket science, i am just uncomfortable with the thought of water behind my tiles!
best regards, adam

A little note on epoxy grout....
Firstly it is mainly used in situations where cleanliness/ sterility is of the upmost importance such as commercial kitchens or hospitals.
Secondly it works out very expensive compared to cement based grouts.
Thirdly is is/can be almost impossible to remove from tiles if left on for too long
Fourthly its nasty stuff.... it carries a COSHH warning so if you do use it wear gloves and if it gets on your skin wash it off as soon as possible as it is very corrosive to the skin. I was told it can burn the flesh down to the bone.
Just so you are aware

Originally Posted by sibs

A little note on epoxy grout....
Firstly it is mainly used in situations where cleanliness/ sterility is of the upmost importance such as commercial kitchens or hospitals.
Secondly it works out very expensive compared to cement based grouts.
Thirdly is is/can be almost impossible to remove from tiles if left on for too long
Fourthly its nasty stuff.... it carries a COSHH warning so if you do use it wear gloves and if it gets on your skin wash it off as soon as possible as it is very corrosive to the skin. I was told it can burn the flesh down to the bone.
Just so you are aware

I have an allergy to some epoxy grouts, my skin will turn red and in the worst case it will blister. Very painful indeed, it takes weeks to clear up. No good wearing gloves either as it makes no difference. It wasnt always the case though so i dont know what changed but after 3 cases of this happening to me i dont touch epoxy anymore.

Originally Posted by Sir Ramic

I have an allergy to some epoxy grouts, my skin will turn red and in the worst case it will blister. Very painful indeed, it takes weeks to clear up. No good wearing gloves either as it makes no difference. It wasnt always the case though so i dont know what changed but after 3 cases of this happening to me i dont touch epoxy anymore.

Ouch!! SirRamic that sounds nasty. It really isn't pleasant stuff is it. Sounds like you have developed a sensitivity to it

Also remember that most epoxies emit toxic fumes which can cause nerve damage if you're exposed to it for long enough.

Wear. A. Proper. ****ing. Face. Mask. When. Using. Epoxy. Period.