Sealant and grout problems

[NBee]

Hello, hope I have put this in the correct forum.

I am having problems in my bathroom and kitchen with sealants. If I use sealant around the edge of the bath, or behind the sink - anywhere that gets wet occasionally - it's not surviving. Within days it shrinks, cracks, or discolours with mould.

Maybe I'm not applying it correctly. The sealand I use is Unibond white bathroom sealant, the tube was a few years old but only recently opened.

Likewise, I recently regrouted the tiles behind my shower. Again, within a few weeks, much of it has shrunk or cracked, and it has become very discoloured. As with the sealant, the tub was quite old.

Any clues as to what I may be doing wrong? If I start again, what should I buy to get the job done properly? I'm not the best DIYer around, but I have done a fair bit of this kind of thing before and am very thorough in the way it is applied.

Would appreciate some advice here! Thanks.

 

[Trazor]

You have used out of date silicon and grout, they both go off after time , even if unopened......

With grout DO NOT buy ready mixed, its rubbish, buy good quality such as Bal.

The silicon I use is Dow Corning 785, very good in my opinion.
Fill your bath with water before you silicon the edge, then drain after about 24 hours.

 

[NBee]

Thanks for the reply.

Having looked at the sealant I was using, I was wrong. It is Everbuild 'Everflex' Bath & Kitchen Sealant.

The grout I used was Unibond, an all purpose waterproof combined wall tile adhesive and grout.

 

[gcol]

As mentioned, the silicone should be reasonably new and you should never use fix n' grout. Always use a powdered grout.

 

[NBee]

Thanks for the tips chaps, I'll pick up the materials suggested this weekend.

How long should I leave the new sealant and grout before allowing it to get wet once I re-apply it?

 

[gcol]

If just siliconing, I usually allow about 4-6 hours before use. If you've put it on thick though, you should allow longer.
For the grout, leave it overnight.

 

[Moz]

regarding the shower me thinks its the substrate? cracking the grout ....what did you tile too ?