Myths and Misunderstandings: Testing the water resistance of grout

[Rizzle from the Portizzle]

...in the words of my daughters hero Elsa..let it go, let it go

time to let this go but respect to any tiler that will spend his free time doing test .showing results weather right or wrong we all learn did you know 99.99% of all bathrooms and shower rooms in the uk are untanked .

 

[Dan]

And 99.9% of failures in them are down to that too!

Yeah fair play for Deano to going well out of his way to prove a point. Not everybody has time for that.

 

[Rizzle from the Portizzle]

You mean like this Dean with no tanking.

View attachment 75202 View attachment 75203 View attachment 75204

And 99.9% of failures in them are down to that too!

Yeah fair play for Deano to going well out of his way to prove a point. Not everybody has time for that.

i am sorry having to disagree here having inspected many failed shower and bathrooms .75% bad pluming ie joints behind shower leaking when under pressure bath not silconed to the wall shower tray under plaster board and so on .10% no silcone any were apartanly plummer ment to come back and do it .
15% realy bad tiling very lippy poor grouting allowing water to make very easy in roads.so what do i make of all this .well all you need for a great job is a plummer who knows how to seal his work .and a tiler who double checks .then seals again .tanking is for when you dont trust anyone .not even your self
.

 

[John Benton]

And jumping out of a plane with one parachute is for the more experienced skydiver

 

[Ajax123]

Swimming pools are rarely tanked. They also rarely fail. The failures you see in showers tend to be a result of what the tiles are stuck to not the fact that the grout allows the passage of moisture. Plywood, plasterboard, mdf etc etc... I also still maintain that whilst grout is not resistant to the passage of moisture more failures occur as a result of poor corners.

 

[Ajax123]

And jumping out of a plane with one parachute is for the more experienced skydiver

To my thinking Jumping out of perfectly good aeroplanes with any number of parachutes is for the more experienced madman....

 

[Rizzle from the Portizzle]

And jumping out of a plane with one parachute is for the more experienced skydiver

tiling the clouds

 

[widler]

Like I said before, most if not all failures are Down to bad workmanship , my ensuite is not tanked, ten years it's been in, only leak it has had is the stupid crappy bathroom.com shower screen I got ,leaking under the 'skirt' andthrough the floor boards

 

[SJPurdy]

Years ago when a new PCI (remember them?) grout came out and was being marketed as suitable for power showers I did a simple experiment:
I took a left over tile and cut some slits through it with an angle grinder. One slit grouted with what I had previously been using - Palace white wall tile grout ( CG1 unmodified); one slit with the Palace and grout addative (that was hell to wash off whenever I used it); and the third slit with the PCI aquafug (I think it was called).
When all the grout had been set for a few days a hosepipe jet was played on the surface for a while (filled a 210 litre water butt and more).
When inspected the unmodified grout had changed to its duller wet colour on the back of tile surface showing that the grout contained water in its "porosity" (that's probably the wrong word). No free water was visible on this back surface but a dry tissue would get damp from it eventually.
There was no change at all to the other 2 grouts and no water seemed to have passed into or through them.
The same result was obtained with a pool of standing water on the surface of the tile for several days (held on the surface using a ring of plastercine).
After these tests I always used the double the cost modified PCI grout in all my shower areas.
Even though I grouted a slitted tile with my replacement choice (CG2) grout when I couldn't get the PCI anymore I never finished repeating the experiment!

On the tanking subject I always felt it was my duty as the professional to inform the customer that the BS for tiling advises that water sensitive substrates are protected from any water penetrating the tiling layer (grouts are water resistant not waterproof etc) by a tanking layer. It was then usually the customers choice wether to pay the extra £'s or not. I would insist in situations (eg mosaic) where I thought it was essential.

 

[widler]

Is tanking BS in domestic showers?
I mean in wetrooms , its obvious , but in a domestic shower ?

Ps as mentioned in my comment about my ensuite, it gets used every day by 4 people, and the eldest is in it for a good 15/20 mins, im sure after ten years,thats over 14000 times it would be abit FUBAR if not tanked ?

 

[Dan]

BAL always recommend tanking in showers used anything more than intermittently. And to use water resistant (not proof) adhesive.

So yeah, always tank showers up to head height.

 

[The D]

BAL always recommend tanking in showers used anything more than intermittently. And to use water resistant (not proof) adhesive.

So yeah, always tank showers up to head height.

I just called the BAL rep and had a chat about this and funnily enough he doesn't agree with dans technical advice ether. He found the idea that water behind the tiles is a normal occurrence ridiculous and his first thought was this would be a health and safety issue.

 

[Dan]

I just called the BAL rep and had a chat about this and funnily enough he doesn't agree with dans technical advice ether. He found the idea that water behind the tiles is a normal occurrence ridiculous and his first thought was this would be a health and safety issue.

The things you'll do to prove a guy wrong lol

How is tanking a health and safety issue? PMSL

 

[Dan]

Oh look. I've just used PowerSpec online and selected power shower and it said this.

Here is the job specification sheet. It would not let me unselect WP1, as tanking IS ESSENTIAL according to BAL. What was the reps name? I think he needs reporting.

Full spec as below.

BAL M40 Tiling Specification (Contractors)

Specification Title: Shower

110
TILING TO STAFFORDSHIRE

Tiles:    Porous Stone / Non Translucent (e.g. Dark Marble) - Mrs Jones Bathroom
Size:    2000mm x 1mm x 1mm
Base/Background:    Plasterboard
Preparation:    General preparation as clause 300
Apply BAL WP1 Tanking as clause 520
PRIMING:    BAL Prime - APD (Apply priming coat of BAL-PRIME APD as clause 462)
TANKING:    BAL-WP1 TANKING SYSTEM (Apply BAL-WP1 TANKING SYSTEM as clause 520)
Bedding:    BAL-THIN BED SOLID BED TROWEL (WALLS) as clause 740
Adhesive:    BAL RAPIDSET FLEXIBLE FIBRE (white)
Grout:    BAL MICROFLEX WIDE JOINT GROUT
Colour:    Grey
Joint width:    3mm


GENERAL REQUIREMENTS

200
BAL PRODUCTS: will be applied strictly in accordance with the sitework instructions on the manufacturer's product data sheets.
All BAL products are covered with a 25 year guarantee, except cleaning products

205
MICROBAN®: Microban® antibacterial protection is not a substitute for good hygiene practices. In order to obtain the best possible long term antibacterial protection, it is strongly recommended that the tiled surface is regularly cleaned with BAL-Microshield cleaner incorporating Microban® antibacterial protection from the BAL-Pro-Hygiene Systems range. Microban and the Microban Symbol are trademarks of the Microban Products Company, Huntersville, NC.

210
INSTALLATION: will be carried out by trained operatives only, using safe working methods and where necessary, suitable protective clothing and equipment.

220
SUITABILITY OF BACKGROUNDS/BASES: Before starting work it will be ensured that backgrounds/bases are:
-    Sufficiently flat to permit the specified flatness of finished tiling.
-    Suitable for tiling in the service conditions to which they will be exposed.
-    Sufficiently strong and rigid to support the tile finish.
If any of the above requirements are not met, the Site Supervisor will be informed and
corrective measures agreed.

280
SAMPLES: Before placing orders representative sample(s) of _ will be submitted. It will be ensured that delivered materials match the sample(s).

290
CONTROL SAMPLE(S): Sample area(s), being part of the finished work in agreed location(s), will be completed and approval of appearance will be obtained before proceeding.

PREPARATIONS

300
EXISTING BACKGROUNDS/BASES GENERALLY: -    Any efflorescence, laitance, dirt and other loose material will be removed.  
-    Any deposits of oil, grease and other materials incompatible with the bedding will be removed.
-    All tile, paint and other non porous surfaces will be cleaned down by washing with water containing detergent, then with clean water.  
-    The background/base will be allowed to dry before fixing tiles.

340
GYPSUM PLASTERBOARD BACKGROUNDS: It will be ensured that sheets are dry, securely fixed and rigid with no protruding fixings and the face intended
to receive the decorative finish is exposed.
Gypsum plasterboard is a suitable background:
- where the weight of tiling does not exceed 32 kg/m? (equivalent to tiles with a thickness of 12.5mm).
- The plasterboard should comply with BS EN 520: 2004 + A1:2009 and be:
- Type 3 where there will be any exposure to moisture.
- Not less than 12.5mm thick.
- Fixed with screws or nails at 300mm centres both horizontally and vertically to seasoned timber or suitable
proprietary framed supports.
- Rigid and free from springiness and surface undulations.
Plasterboard wall linings fixed with plaster dabs or adhesive should be allowed to stand for 10 days before being tiled.

462
PRIME WITH BAL-PRIME APD: Where required, the undiluted primer will be brush applied to the background/base and allowed to dry.
Note: In the case of Anhydrite/ Calcium Sulfate apply two coats. The first coat should be diluted 1:1 with water
and allowed to dry before applying a second, undiluted coat. It may also be used diluted 1:1 with clean water on
concrete floors for example to prevent the formation of air bubbles when applying BAL self smoothing compounds.
Allow to dry before tiling commences

520
TANKING WITH BAL-WP1 COATING: -    All surfaces will be primed with BAL-PRIME APD and allowed to dry.
-    BAL-WP1 COATING reinforced with BAL-WP1 POLYESTER TAPE will be applied at the following locations:
-    Internal and external corners of walls/partitions and their junctions with bases, upstands, columns, etc.
-    Pipe penetrations, drainage channels and outlets.
-    Junctions of different base/background materials.
-    Cracks and joints in background/base.
-    BAL-WP1 COATING will then be applied to the walls.
-    BAL-WP1 COATING will then be applied to the floor. For heavy duty wet areas (e.g. communal showers and industrial wet process areas) and where some vibration or deflection in the base may be expected (e.g. timber bases) BAL-WP1 POLYESTER MATTING will be used as reinforcement.
-    The membrane will be allowed to dry for at least 24 hours before tiling.

FIXING

600
FIXING GENERALLY: -    It will be ensured that there are no unintended colour/shade variations within the tiles for use in each area/room.
-    Variegated tiles will be thoroughly mixed.
-    Tiles will cut neatly and accurately.
-    Before the bedding material sets, adjustments will be made to give a true, regular appearance to the tiles and joints when viewed under their final lighting conditions.
-    Surplus bedding material will be cleaned from the joints and face of the tiles without disturbing them.

610
ADVERSE WEATHER: - Do not fix tiles if the temperature is below 5�C or in damp conditions.
- Do not use frozen materials or apply adhesives to frozen or frost covered surfaces.
- Do not fix tiles if the temperature of the background/base is in excess of 65�C.
- Take adequate precautions to protect work from inclement weather, frost and premature drying out.

620
SETTING OUT GENERALLY: -    Joints will be true to line, continuous and without steps.
-    Joints on walls will be truly horizontal, vertical and in alignment round corners.
-    Joints in floors will be parallel to the main axis of the space or specified features.
-    Cut tiles/slabs will be kept to a minimum and will be as large as possible and in unobtrusive locations.  
-    Joints in walls and floors will be in alignment where practicable.
-    Where positions of movement joints are not specified they will be agreed with the Site Supervisor.
-    The setting out of _ will be in accordance with drawing(s) _.

640
FLATNESS OF TILING: Sudden irregularities will not be permitted. When checked with a 2m straightedge with 3mm thick feet at each end, placed anywhere on the surface, the straightedge will not be obstructed by the tiles and no gap will be greater than 6mm.

721
FIXING STONE (WALLS/FLOORS): If required the tiles will be sealed prior to fixing as per manufacturer's recommendations.
As tile sizes and
thicknesses increase, however, solid bed fixing can become more difficult to achieve and the weight of the stone
increases. BS 5385: Parts 1 & 2 recommend the use of mechanical fixings, particularly for areas of tiling which are
above first floor height. Seek further instructions where there is any doubt.

Before fixing the stone tiles they will be checked to ensure that the surface to be adhered to is clean and free from
dust. If present, dust will be removed

740
ADHESIVE BEDDING: THIN-BED/SOLID-BED: A BALTHIN BED SOLID BED TROWEL will be used, or where the background/base is not sufficiently flat to achieve a
solid bed of adhesive with this trowel, a BALTHICKBED SOLIDBED TROWEL will be used.  
The adhesive will be applied to the dry background/base in areas up to 1m?. For porous backgrounds/bases, a skim coat
of adhesive will first be applied prior to combing the remaining adhesive while the skim coat is still wet.
Any depressions (ribbed, keyed profiles, etc.) to the backs of tiles will be filled with adhesive.
Tiles will be pressed firmly into the adhesive with a twisting/sliding action ensuring that as far as possible no
voids are left behind the tiles.
The use of a BAL Mosaic Trowel should be considered when fixing mosaic tiles.

880
CHECKING CONTACT AREA: As work proceeds and before the bedding has set, random tiles will be carefully removed to verify that the contact area is as specified. The initial bedding material will be removed and the removed tiles will be buttered with fresh material and refixed.

GROUTING / COMPLETION

900
GROUTING: -    The bedding material will be allowed to harden sufficiently before grouting.
-    It will be ensured that joints are 6mm deep (or the depth of the tile if less), and are free from dust and debris.
-    Joints will be completely filled using a rubber grouting squeegee and tooled to an approved profile. The surface will be cleaned off and left free from blemishes.

910
COLOURED GROUT: The potential risk of staining will be checked by applying the grout to a few tiles in a small trial area. If discolouration occurs BAL-PROTECTIVE SEALER will be applied and the trial repeated.

911
GROUTING JOINTS GREATER THAN 3mm: When grouting joints that are greater than 3mm in width a suitable grout from the BAL range will be used, e.g. BAL-WIDE JOINT GROUT. When using such materials a test will be performed to ascertain the risk of the grout scratching the face of the tile and the application techniques amended accordingly.

960
PROTECTION (GENERAL): All completed areas will be adequately protected and kept clean. Any droppings will be cleaned off immediately.

 

[Dan]

This time with Ceramic tiles. Power shower still.

Again WOULD NOT LET ME UNSELECT WP1 BECAUSE IT IS ESSENTIAL.

Job spec.

BAL M40 Tiling Specification (Architect)
Specification Title: Shower
110
TILING TO STAFFORDSHIRE

Tiles: Porous Stone / Non Translucent (e.g. Dark Marble) - Mrs Jones Bathroom
Size: 2000mm x 1mm x 1mm
Base/Background: Plasterboard
Preparation: General preparation as clause 300
Apply BAL WP1 Tanking as clause 520
PRIMING: BAL Prime - APD (Apply priming coat of BAL-PRIME APD as clause 462)
TANKING: BAL-WP1 TANKING SYSTEM (Apply BAL-WP1 TANKING SYSTEM as clause 520)
Bedding: BAL-THIN BED SOLID BED TROWEL (WALLS) as clause 740
Adhesive: BAL RAPIDSET FLEXIBLE FIBRE (white)
Grout: BAL MICROFLEX WIDE JOINT GROUT
Colour: Grey
Joint width: 3mm

111
TILING TO MRS JONES CERAMICS SHOWER

Tiles: Glazed (Porous Body) - Shower with Ceramic Tiles and Wide Joint Grout
Size: 200mm x 200mm x 4mm
Base/Background: Gypsum plaster
Preparation: General preparation as clause 300
Apply BAL WP1 Tanking as clause 520
TANKING: BAL-WP1 TANKING SYSTEM (Apply BAL-WP1 TANKING SYSTEM as clause 520)
Bedding: BAL-THIN BED SOLID BED TROWEL (WALLS) as clause 740
Adhesive: BAL WHITE STAR PLUS
Grout: BAL EASYPOXY
Colour: Grey
Joint width: 3mm