Space / gaps and mould behing shower tiles.

[jj74cycling]

Hi all, this is my first post and it is 'asked' in the hope that i can fix the problem without the need for a professional (and save money) my DIY skills are okay - I certainly don't mind giving most things ago.
I recently moved into a newish house hence 'movement' (I think) had caused slight gaps in the grouting between some of the tiles in our en-suite shower room. Thinking that I could just scrap out the old grout and apply new grout.
However, upon scrapping out the old grout, it soon became clear that there was very little supporting the lower tiles in terms of plasterboard / backing. Hence, water had been getting through the gaps in the grout and causing mould in the cavity. Obviously, the original 'builders' have been slack and not finished a job to a satisfactory standard.
Anyhow, can anyone recommend a long term fix - I am not interested in short term - make do fixes. At a guess, i would 'kill' the mould with a spray, fill the cavity with expanding foam and re-grout; What would a professional do?
Any help would be greatly appreciated. pics enclosed. Only the tile shown is loose, the others are firmly fixed. There is some solid matirial towards the top of teh loose tiles but cavitys which go back about 4cm lower down (behind teh tile in the pic).
Ideally, I want to avoid retiling altogether or adding a plastic 'screen'. unfortunately, i do not have any spare tiles of teh same type.

[thescruff]

If the plasterboard has got wet, the long term fix is a rip-out, backer board and re-tile.

Depends how bad the Plasterboard is really.

[jj74cycling]

hopefully here are pics

At the top of each index it tells you how to post pics, and how to re-size them. Jpeg format is best.

[Simon Site Manager]

Whoops, pics didn't work!

S

[dewaltdisney]

Have a look at this http://www.knauf.ie/aquapanel/

And the DIY guide http://www.teachmediy.co.uk/NetsiteCMS/ ... panel.html

Use self mix adhesive and grout too. Have a look here http://www.bal-adhesives.co.uk/products/microflex

DWD

[jj74cycling]

lets try the pics again!!!!

[wine~o]

As Said earlier, depends on how bad the plaster/board is behind the tile, remove the affected tiling, allow to dry thoroughly, try the plaster.for strength...if ok use a waterproof adhesive to re-apply the tiles, wait 24 hours, then grout using a quality grout,wait 24 hours for grout to dry beforeusing shower.. you will have to re-do the silicone as well...

[jj74cycling]

Thank you for all comments. How easy is it to remove tiles complete (without breaking them). All but one tile is firmly stuck and I don't have any spares.

[wine~o]

Thank you for all comments. How easy is it to remove tiles complete (without breaking them). All but one tile is firmly stuck and I don't have any spares.

That's the good news...just remove the loose one for now...and don't use the shower until everything has properly dried out..

[Colour Republic]

I'm going to take a stab at what's happened here...

Is there grout in the internal corner? if there is, then there shouldn't be! Internal corners should be left free of grout and siliconed instead (not siliconed over grout) this allows for movement in the substrate.

What might have happened is the seal in the internal corner has failed and water has worked its self behind the tiles. This may have happened because of expansion or contraction which would cause the tiles to tent and debond.

I assume that the adhesive is a tubbed adhesive judging by the colour (but could be a white cement based addy) and if you have a void behind this tile then the tubbed adhesive has failed as it is not designed to go so on so thick.

I would rake out all grout, playing attention to the internal corner. Re-fix any loose tiles with a cement based adhesive, Re-grout with a good quality grout such as BAL or Mapei being careful to keep the internal corner clean, then silicone internal corner and round the bath.

This may or may not work depending on how damaged the plasterboard is. I would give it a go and monitor it, failing that i'm afraid it's a strip out and redo, if that is the case you can use a water resistant tile backerboard or plasterboard tanked with a paint on membrane to keep costs down (BAL WP1 or Mapeigum)

-- Fri Aug 20, 2010 6:55 pm --

As Said earlier, depends on how bad the plaster/board is behind the tile, remove the affected tiling, allow to dry thoroughly, try the plaster.for strength...if ok use a waterproof adhesive to re-apply the tiles, wait 24 hours, then grout using a quality grout,wait 24 hours for grout to dry beforeusing shower.. you will have to re-do the silicone as well...

Whilst most people will use a freashly grouted shower just a few days later without issues, you'll find that a lot of grout manufacturers will not guarantee thier products unless it has been given 14 days to cure

[wine~o]

Whilst most people will use a freashly grouted shower just a few days later without issues, you'll find that a lot of grout manufacturers will not guarantee thier products unless it has been given 14 days to cure

14 Days!!!! my armpits could knock a Donkey out at 50 yards if I don't shower for half that time

[Colour Republic]

Whilst most people will use a freashly grouted shower just a few days later without issues, you'll find that a lot of grout manufacturers will not guarantee thier products unless it has been given 14 days to cure

14 Days!!!! my armpits could knock a Donkey out at 50 yards if I don't shower for half that time

I know, I know!! Don't shoot the messenger!

[royaloakcarpentry]

3 days for addy to go off and then 14 days for grout.........plenty of manufacturers combine to get that figure. Some are less.

Hard to diagnose from the pics what has been the route cause of it. As pointed out it could be a number of reasons and this would include the tray being improperly installed. There could even be a leak on the trap, soaking onto the floor and spreading up the plasterboard. This would not necessarily affect the floor tiles.

We deal with these sorts of problems on a regular basis in a lot of various developments of apartments. Normally it is down to poor workmanship but you are never 100% sure until you start to rip out.

You can take tiles off with a little bit of ''softly softly catchey monkey''. Any adhesive can be cleaned off by soaking in water and then scraping it back.

[wine~o]

14 Days!!!! my armpits could knock a Donkey out at 50 yards if I don't shower for half that time

I know, I know!! Don't shoot the messenger!

CR....I don't need to shoot the messenger...I can knock them out...and if the wind is in the right direction...Dorset to Brighton

[royaloakcarpentry]

Sounds like you live in new Milton lol