Tried to seal a shower tray twice now, and after a couple of weeks the sealant starts to ripple up and eventually fall off. I guess because there’s a tiny amount of movement when people get in and out of the shower?
Any tips for sorting this out? I’ve just been using a cheap B&Q sealant – surface is clean and dry but I’ve not done owt special to prep it. More expensive stuff worth it?

There is stuff that sticks better than cheap sealant. I use polysulphide sealant for areas that are likely to move. It stinks at takes ages to go off though. Not sure how suitable it is for showers. Always worth looking at other sealants over the basic sstuff.

2I’ve just been using a cheap B&Q sealant – surface is clean and dry but I’ve not done owt special to prep it. More expensive stuff worth it?”

yes yes and yes.

struggled with this for ever on my shower … but dow corning or unibond stuff really is worth it for this job…. one application – hasnt leaked since…. that was 2 years ago. the cheap stuff would be leaking again in a week.

I moved from cheap stuff to Dow Corning (785) but for it much better anti-mould properties, over any other quality it possessed. I’d look into making the base more stable, in your case

How about the 90 degree stick on sealing strip.

Everwhite

I use this stuff – its the absolute business and I can confirm no leakage around shower tray or mould after many years.

Everwhite for me.Sealant used to get mouldy within a couple of months and so far with Everwhite not a sign of it in 6 months.

I’ve read here that the Dow Corning sealant is very good – I’ve just used some so time will tell.
Maybe you need to de-grease the area you’re applying the sealant to and also standing in the shower while applying the sealant may help as it will pull the tray down if there is any movement (In the same way that you’re supposed to fill a bath with water before applying sealing around the edge).

Try loading up your shower tray before sealing in the same way that a plumber half fills a bath before sealing, let it dry then remove the load.

+1 for jamesy. Get good quality i.e. expensive sealant. Stand on your tray or sit a stool in it and sit on it and read your book whilst it goes off.

Another +1 for loading it. Couple of 25ltr water containers would do.

Load up the shower tray as stated above but also use sealant remover and a blade to ensure you have a clean surface to bond to.

Thks all, bought some pricey unibond stuff and will try weighting the tray as suggested.

Apologies for a bit of a hijack, but is it possible to get a decent bond between existing and new sealant? 1 of the 3 sealed sides of our shower tray has started to peel away from upper surface of tray – others are fine. Was hoping to remove, clean up and redo only the defective run?

Do it all onlysteel do it all! I would say only way to guarantee complete seal.

also just to check , you are pushing it in with the wet finger or a tool – your not just laying it on with the nozzle and expecting it to seal are you ?/

Did you use a silicone removal spray? If so, make sure it’s really clean before sealing. In fact, make it really clean anyway.

But also, load the tray and leave it loaded and unused for 24 hours, 48 if possible.

Sounds like the tray needs proper support. Often floors are too flexy to properly support a shower tray or timber plinths badly constructed.It is also very common to not support baths properly where they touch walls (a piece of 2×2 as a prop down to the floor sorts this).
As others have said, surface should be free from old sealant and muck. Take the Unibond back to the shop, I’ve yet to be impressed by anything they produce. Buy yourself Forever White made by Everbuild.

Unibond anti mold stuff here. Used on the shower at our old place and done the bath when we moved in here. Shower was still good couple of years later. Bath is 14 months now and still looks like the day I did it. No leaks either. Surfaces well cleaned of old sealant before application.

I tried a few things with mine. I doubt there is much difference in performance between various chemistries but there will be better quality sealants out there. I’m sure I just went with BandQ own brand stuff but not the cheapest.

Good prep is always key. Buy some silicone remover and then wipe with meths/IPA to get a clean dry surface.

I tried the exterior strips afte ra few goes and they were better. Finally got sick of redoing it every 6 months and so spent £50 and got some tele seal

http://www.teleseal.co.uk/technology.html

Worked really well and has been good untouched for 18 months. I’d recommend it if you have a bit of movement in your shower tray.

Use dowcorning 785. Clean all the old silicone out 1st as new wont stick to old. Also silicone won’t stick to anything wet so don’t use the shower 24 hrs prior to application. Weight the tray and then seal using a wet finger or tool to smooth off, leave for 24hrs after application to go off. Job jobbed

Dow Corning or Sika is the way forward (Arbo is also pretty good). I hate paying Screwfix prices for silicone but it is worth paying for the decent manufacturers. Acetoxy silicone (the stuff that smells like vinegar) is not a good as the neutral cure stuff ( I find).

Make sure the bead is a minimum of 6-7mm (would suggest more) otherwise it will crack/pull away fairly quickly.

Use CT1. Remove all old stuff and clean thoroughly. Loading the tray is a good shout.