Applying silicone correctly to your bathroom TL;DR: £2 and some patience ?

As you might have guessed, something very different this week...

Earlier this year, we had an issue with our bathroom, the silicone around the bath tub was coming away from the wall and needed re-doing. It's not like I haven't used a skeleton gun before, but thinking back it was mostly for patching rather than for the finishing it can give you.

I removed the old silicone (which was actually recently applied), cleaned the area out and applied a whole new bead around the tub. It looked great and I was really pleased with the results... until about a month later when we could see mould starting the form again. It was really frustrating as I had spent days preparing the bath and filled it when applying to account for variances in weight. Fat lot of good that did.

I left it alone for a while, thinking I'll have to get someone more experienced to help out when I saw this tweet from an old friend on mine:

Well, three good things have (so far) come from 2020. 1) I learned and fixed a toilet flush with new parts. 2) Ordered the right parts and replaced broken parts on our washing machine. 3) Learned how to apply shower/sink seals the professional way.

I got in touch and it turns out I only did one of three things correctly. Here's the video he sent me that gives loads of practical advice for doing it right with lots of theory thrown in:

Filling the bath is a fantastic idea, there's definitely a shift as the bath fills and empties with water and even more so when you add the weight of a person.

Turns out the two steps I was missing were very crucial. After applying the bead of silicone, I was finishing with the tip of my finger. This actually introduces two issues. You end up wiping too much away so the bead doesn't get enough purchase on any surface and then the curve you introduce means that it is too weak at crucial points to be able to cope with the changes in weight.

Taking those three things into consideration, I don't think I'll ever have an issue applying silicone again. For the finish, I was sceptical but plunged all of £2 into this sealant finishing tool and I'll treasure it forever! The 10mm side looks too big when you apply it (in my opinion) but it actually gives a very nice and consistent finish.

My last tip would be to start from your dominant side and finish on your weaker side. I made the mistake of doing the left first on one application which made the rest harder. I also had to re-do our shower and started from the right which made it way easier to just get it done.

For the shower, I couldn't weight it down with water and luckily had a load of 20kg bags of plaster left over from some building work we had done which I put into the shower tray before applying.