New shower - sealant not sealing...

[daneaston]

Hi all

I've just re-done our shower. New shower tray and new tiles. I've finished off with sealing around the bottom of the tiles and shower door, but the sealant has all lifted from the shower tray. I know it's leaking because about 5mins after running the shower a little bit, water was leaking onto the bathroom floor from under the shower door.

I used Unibond transluscent sealant and a Moretti shower tray from Screwfix. ANY help gratefully received!

http://www.diy.com/diy/jsp/bq/nav.j...<{9372100}/specificationsProductType=sealants

http://www.screwfix.com/p/moretti-shower-tray-square-805-x-805-x-45mm/47999

 

[HERTS P&D]

Were the tiles completely dry when you applied the silicone? and free from dust?

Andy

 

[daneaston]

Yes - but the sealant seems to have stuck to the tiles fine. It's jus the tray (which was also dry/dust free).

 

[ic1927]

Did you remove the protective cellophane from the tray before installation ?

 

[daneaston]

I removed it once all the tiling was done (to protect the tray) but obviously before I sealed.

I'm glad everyone else is as stumped as me so far...

 

[elrobbo82]

did you weigh the tray down while sealing and until the sealant had set. you need to do this because when you stand on the tray for a shower you will push the tray down slightly and the sealant will peel off it!

 

[p4ult]

I have been told this stuff is the best,
http://www.screwfix.com/p/dow-corning-785-white/58308

Used it in my shower and has worked a treat.

Did you clean the joints with meths before hand?

 

[Richard C]

Chances are the tray will still have traces of the release agent used to ensure the tray separates from the mould when it was made. This release agent is silicone based & must be thoroughly cleaned off; do not use white spirit & even meths is not ideal, use an alcohol based cleaner. Use only a quality sanitary silicone sealant as posted, not the one that didn't work.

Weight loading is a factor with baths but should not be significant with a shower tray; if it is, you have a serious problem with the floor construction.

 

[elrobbo82]

Chances are the tray will still have traces of the release agent used to ensure the tray separates from the mould when it was made. This release agent is silicone based & must be thoroughly cleaned off; do not use white spirit & even meths is not ideal, use an alcohol based cleaner. Use only a quality sanitary silicone sealant as posted, not the one that didn't work.

Weight loading is a factor with baths but should not be significant with a shower tray; if it is, you have a serious problem with the floor construction.

depending on the quality of the tray as well, i have seen them flex quite a bit when load is applied. i would always weight load just in case as it doesn't cost anything and provides piece of mind.

 

[Richard C]

depending on the quality of the tray as well, i have seen them flex quite a bit when load is applied. i would always weight load just in case as it doesn't cost anything and provides piece of mind.

Not really much you can do about a crap tray except don't use one!

 

[elrobbo82]

your right, but people do. some people don't know the difference!

 

[Nige F]

I thought I replied to this Use Neutral Curing Silicone not the acetoxy ( vinegar smelling ) stuff

 

[Nige F]

Chances are the tray will still have traces of the release agent used to ensure the tray separates from the mould when it was made. This release agent is silicone based & must be thoroughly cleaned off; do not use white spirit & even meths is not ideal, use an alcohol based cleaner.

Isn`t meths denatured alcohol

 

[Richard C]

Isn`t meths denatured alcohol

Alcohol based probably wasn’t the best choice of words; the problem with meths is it also contains a cocktail of other additives primarily designed to make it less palatable & usually dye, all of which may leave a residue; a purer IsoPropyl alchohol based cleaner would be a better choice.

I actually use an automotive panel wipe/degreaser to clean down & that will get rid of practically anything including silicone residue; I’ve got a few 5 litre tins left over from previous involvement in spraying.

 

[daneaston]

So if this sealant sticks to anything, what's the importance of removing ALL the old sealant. And is it really all? Or 'as much as you realistically can'?