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Discuss Advice needed - poor tiling job, dot and dab not to BS5385 in the Tiling Advice | Tile Forum area at TilersForums. USA and UK Tiling Forum

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We recently had a bathroom fitting in who said he used dot and dab to fix tiles to the wall and in the shower areas and also stated that any gaps behind tiles e.g. Mosaics would get filled in by grout so it would be fine. We can however hear what we think are some voids behind the large format tiles.

We have challenged him with info from tile association and what we know of British standards but he has now said (to counter our argument against dot and dab) he "back buttered" and this is recommended. He also stated "the skill of the installer is paramount".

We also challenged him and said that the shower area should have been waterproofed. He said it was unnecessary and now is saying water resistant https://www.tilersforums.com/forums/tile-adhesive/ and grout is enough. We don't believe this is the case according to tile association but don't know re British standards. Also is a domestic shower classed as a "wet area"?

He also said the British standards can't take into account "differing situations that may be encountered in different properties " but surely a standard house and bathroom installation shouldn't cause so many issues and should still be covered by what is stipulated in Brit standards ?

Lastly he has said there is no excess lippage as per bsi recommendations. Does anyone know the recommendations and how we can check them? We know there are some significant dips in the mosaic especially at the edges next to large format tiles...

Any advice greatly received. The tiler has accused us of picking out our own grout and has lied throughout our comms with him. It's heading towards full on dispute :-(
 

Andy Allen

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Dot and dab method of tile is wrong especially if there are voids behind the tiles....
There's no excuse for it and it should be all replaced and done properly.
 
T

Tile Shop

We recently had a bathroom fitting in who said he used dot and dab to fix tiles to the wall and in the shower areas and also stated that any gaps behind tiles e.g. Mosaics would get filled in by grout so it would be fine. We can however hear what we think are some voids behind the large format tiles.

We have challenged him with info from tile association and what we know of British standards but he has now said (to counter our argument against dot and dab) he "back buttered" and this is recommended. He also stated "the skill of the installer is paramount".

We also challenged him and said that the shower area should have been waterproofed. He said it was unnecessary and now is saying water resistant https://www.tilersforums.com/forums/tile-adhesive/ and grout is enough. We don't believe this is the case according to tile association but don't know re British standards. Also is a domestic shower classed as a "wet area"?

He also said the British standards can't take into account "differing situations that may be encountered in different properties " but surely a standard house and bathroom installation shouldn't cause so many issues and should still be covered by what is stipulated in Brit standards ?

Lastly he has said there is no excess lippage as per bsi recommendations. Does anyone know the recommendations and how we can check them? We know there are some significant dips in the mosaic especially at the edges next to large format tiles...

Any advice greatly received. The tiler has accused us of picking out our own grout and has lied throughout our comms with him. It's heading towards full on dispute :-(

Wow.... sounds like he is proper on the defensive.....

As far as I am aware, British Standards don't use exact words saying that spot fixing or dottin' and dabbin' is wrong. However it does say that the tiler should achieve as close to full coverage as possible, which most spot fixing will not do, whatever anyone says.

If he is back buttering and applying more spots of https://www.tilersforums.com/forums/tile-adhesive/ on top, he is wasting his time as most of the back spread of https://www.tilersforums.com/forums/tile-adhesive/ is now elevated from making contact with the substrate and still leaving voids.

A "wet area" is anywhere of regular/intermittent contact with water or steam. https://www.tilersforums.com/forums/tile-adhesive/ and grout being water resistant is fine providing the coverage is solid (no voids) and compressed sufficiently when fixing as this will drastically reduce the flow of water from making contact with the substrate in such quantities that would potentially cause a problem. Again, spot fixing allows free movement of water which can saturate all contacting https://www.tilersforums.com/forums/tile-adhesive/ and reducing the already limited bond strength.

Lippage is specific in BS. no more than 1mm on joints less than 6mm, 2mm allowance on joints 6mm and over. This is dependant on the tile so if it is rustic or bowed it may not be possible and BS would still allow it. If the tile however is perfectly flat with minimal to no surface texture, he has no excuse. Fixing thinner mosaics against thicker tiles is difficult, but not impossible if he knows what he is doing. There are ways of leaving a solid coverage and small notches for the mosaic to press into. But I have never had to do it so would be better if someone with more experience can advise you better on that one.

Alot of "old school" tilers say that tiles need spot fixing to allow better adjustment over uneven surfaces. Good modern tilers will spread the https://www.tilersforums.com/forums/tile-adhesive/ on the wall and back spread the tile with a variety of different trowels (trial and error) to get the correct level AND full coverage.
 
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Soso

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OP
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Soso

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Wow.... sounds like he is proper on the defensive.....

As far as I am aware, British Standards don't use exact words saying that spot fixing or dottin' and dabbin' is wrong. However it does say that the tiler should achieve as close to full coverage as possible, which most spot fixing will not do, whatever anyone says.

If he is back buttering and applying more spots of https://www.tilersforums.com/forums/tile-adhesive/ on top, he is wasting his time as most of the back spread of https://www.tilersforums.com/forums/tile-adhesive/ is now elevated from making contact with the substrate and still leaving voids.

A "wet area" is anywhere of regular/intermittent contact with water or steam. https://www.tilersforums.com/forums/tile-adhesive/ and grout being water resistant is fine providing the coverage is solid (no voids) and compressed sufficiently when fixing as this will drastically reduce the flow of water from making contact with the substrate in such quantities that would potentially cause a problem. Again, spot fixing allows free movement of water which can saturate all contacting https://www.tilersforums.com/forums/tile-adhesive/ and reducing the already limited bond strength.

Lippage is specific in BS. no more than 1mm on joints less than 6mm, 2mm allowance on joints 6mm and over. This is dependant on the tile so if it is rustic or bowed it may not be possible and BS would still allow it. If the tile however is perfectly flat with minimal to no surface texture, he has no excuse. Fixing thinner mosaics against thicker tiles is difficult, but not impossible if he knows what he is doing. There are ways of leaving a solid coverage and small notches for the mosaic to press into. But I have never had to do it so would be better if someone with more experience can advise you better on that one.

Alot of "old school" tilers say that tiles need spot fixing to allow better adjustment over uneven surfaces. Good modern tilers will spread the https://www.tilersforums.com/forums/tile-adhesive/ on the wall and back spread the tile with a variety of different trowels (trial and error) to get the correct level AND full coverage.
He has definitely gone off and read some of the British standards to try and mitigate anything we might say is wrong but looks like he has misquoted some of it. Does the British standard say anything about it being essential to waterproof regardless of water resistant grout and https://www.tilersforums.com/forums/tile-adhesive/ being used ? This is what the tile association told us anyway.
 

Andy Allen

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Waterproofing or tanking a shower area is not a regulatory practice as it is in other countries, it is always recommended but at the tilers / customers discretion..
 
T

Tile Shop

BS5385 part 4:2015:

7.2.3 Installations not immersed but subject to occasional wetting.
In installations where contact with water is only intermittent, and the installation has had the opportunity to dry out between periods of use, e.g. domestic (not power) showers, 7.2.1 and the following should apply: (have checked 7.2.1 and all it says relating to your query may be not to use plaster or gypsum based materials in wet areas as they are unstable when wet or when combined with cement based materials).

a) The background should preferably be cement and sand rendering or dense concrete. Sheets and boards should not be used unless they are dimensionally stable in changing moisture conditions. Tiles should be solidly bedded in water resistant https://www.tilersforums.com/forums/tile-adhesive/.

b) The joints between the tiles should be water-resistant but additional protection can be obtained by using an impervious grout.

c) The gaps between wall and shower tray/bath should be sealed, particularly where the installation is located on a suspended floor.

NOTE 1, for water sensitive backgrounds e.g. gypsum plaster, additional protection in the form of a waterproofing tanking system may be considered.

NOTE 2, The use of impervious grouts and adhesives is no substitute for a tanked installation.

More to follow when I get a bit more time.... 7.2.4 which is for wetrooms and domestic power showers. or you can have a browse yourself:
British Standards no longer available at Newcastle Library.... But here's another way. - https://www.tilersforums.com/threads/british-standards-no-longer-available-at-newcastle-library-but-heres-another-way.83947/
 
T

Tile Shop

Ahhhhh...... found it. Or at least part of it. In the June update of BS5385 Part 1.... but now they should amend part 4 to suite!

6.1.1.3 Tanking
In Wet areas, e.g. showers, wet rooms and steam rooms, substrates should be protected with a suitable proprietary tanking membrane system.

The weight capacity of the tanking system should be capable of carrying the load of the tiles and https://www.tilersforums.com/forums/tile-adhesive/. If mechanical fixings are to be used the membrane manufacturer should be consulted.

Where the substrate is to be protected with a tanking membrane the weight restrictions of the installation might be reduced therefore the membrane manufacturer should be consulted.

NOTE This can be a proprietary sheet membrane or a liquid applied water impermeable product.
 
T

Tile Shop

One other amendment made is in 7.2.1.6 Tile Joints (quite why it was put in here I don't know.... think they messed up and it should have gone in 7.2.1.5.......... damn I'm such a geek!)

"Tiles should never be fixed with butt-joints, as an adequate width of joint is necessary for the relief of local stress.

Tiles should not be fixed using the dot and dab technique."

BOOM!
 
OP
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Soso

TF
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Ahhhhh...... found it. Or at least part of it. In the June update of BS5385 Part 1.... but now they should amend part 4 to suite!

6.1.1.3 Tanking
In Wet areas, e.g. showers, wet rooms and steam rooms, substrates should be protected with a suitable proprietary tanking membrane system.

The weight capacity of the tanking system should be capable of carrying the load of the tiles and https://www.tilersforums.com/forums/tile-adhesive/. If mechanical fixings are to be used the membrane manufacturer should be consulted.

Where the substrate is to be protected with a tanking membrane the weight restrictions of the installation might be reduced therefore the membrane manufacturer should be consulted.

NOTE This can be a proprietary sheet membrane or a liquid applied water impermeable product.
oh my gosh, that is perfect ! Thank you so so much. He fitted our bathroom in May 2018 but I'm sure the new standard should still apply given its what the tile association said too before ?
 
OP
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Soso

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One other amendment made is in 7.2.1.6 Tile Joints (quite why it was put in here I don't know.... think they messed up and it should have gone in 7.2.1.5.......... damn I'm such a geek!)

"Tiles should never be fixed with butt-joints, as an adequate width of joint is necessary for the relief of local stress.

Tiles should not be fixed using the dot and dab technique."

BOOM!
I guess this hits on two counts. Some of the mosaics are right next to each other without any room for grout as he hasn't spaced some properly and also dot and dab expressly mentioned is fantastic !
 

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