I have just had an en-suite shower rebuilt, ie new plasterboards for the walls (the old ones were black due to leakage), therefore new tiles, tray, door, etc. Its a very basic construction of three tiled sides and one glass door, which I would have completed myself if I didn't work full time and travel a lot with my job. So I trusted the work to a family member who did a good job of the general construction, but rushed the sealing and as a result there are numerous gaps in the sealant e.g. where tiles meet tiles in the corners, and where tiles meet the shower tray.
The shower has never been used so there has been no water penetration.
What tips do you have for the removal of the current sealant and the application of new sealant?
to remove the old sealant use a piece of wood 18mmx18mm.
sharpen the end to represent a chisel if you like and gently ease the sealent off. Re-sealing is an art, done properly you use a similar stick to smooth the sealant after application, with a water spray
As you correctly say, you will have to remove the current sealant first - never be tempted to go over exisiting sealant, it just never works
I find the best way is to cut it out using a craft knife with those flexible, snap off blades
Use the knife so that the blade is almost flat against the surface you are cutting the sealant from - this will avoid any damage to the shower tray
With the blades being so flexible, you can get into any awkward areas
Clean away all loose bits of grout and sealant and wipe down with a damp cloth
The best tool for using with silicone sealant I have found is from Screwfix - Code 28167 - £10.21 and is called Fugenboy (have no idea what it means)
It may seem a bit overpriced for 3 bits of plastic but is worth double the money once you use it and see the end result - brilliant, especialy for the diy market
might also be worth establishing why the sealant has come away in the first place, especially if it's a new fixture. is there any movement in the shower tray or walls? if the tray is on feet and not bedded down then there could well be some movement.
you don't want to go to all the effort of re-sealing only for it to happen again.
i usually put a 25kg bag of sand in the tray prior to and during sealing and leave it there until the sealant has cured. same principle as half filling a bath whilst sealing.
Thanks to all for your replies, very helpful. As an update, after removing the existing sealant, and when I measured the gaps where tile meets tile down the corners of the walls I found that the gap in some places was up to 9 mm wide, and about 12 mm deep, in other places it was only a couple of mm wide. I suppose I could fill the big gaps with a purpose made filler, cut the filler back to the surface (after it has hardened), then seal on top of that, but I am awaiting a professional who is coming to the house to view the job and advise on the correct course of action. The gap between the tiles and the tray is no more than a few mm so that is perfectly acceptable.
I will post a further update to advise later, but thanks again for the advice, it is much appreciated.