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Silicone sealant - it’s the clever stuff that keeps water from escaping out into places it shouldn’t. Typically you might think of silicone for sealing the edge around a shower tray or bath, but it’s also used around windows and in the kitchen too. You’ll find it anywhere that requires a water-tight seal.
Whilst silicone sealant is hard wearing stuff, eventually it will need replacing. Too much abrasive cleaning can slowly wear it away, and when used in bathroom situations, it can also discolour and even be prone to a bit of mould.
If you need to remove and replace silicone sealant within your home, then we’ve created this step-by-step guide for you. We’ll show you exactly how it’s done, the professional way. Don’t worry if you’re not an expert DIYer either, this is a really simple tutorial which anyone can accomplish.
If you have any old silicone sealant in place already, it’s really important to remove this before going on with a new application. Existing silicone that is in poor condition and prone to leakage won’t be fixed by applying more over the top.
There are two options available when it comes to removing sealant; cutting and scraping it away or purchasing a more expensive sealant remover, which will break down the sealant for you.
To help you decide which is the better option, we’ve weighed up the pros and cons:
Less to spend on tools and materials
Can damage the surface beneath
Guaranteed to work
May be very difficult to remove deep-set sealant or sealant awkward spaces
Time-saving and easy removal
Varying degrees of success in how well different brands work
Less scraping means less chance of damaging surface
Take a sharp knife and cut into the top and bottom edge of the silicone right across the whole bead. You should be extra careful when doing this so as not to damage the surface beneath, which is particularly important if you’re working on softer material such as acrylic baths and wooden worktops.
Using a scraper, carefully push along your cut bead of silicone and it should start to remove away from the surface. This is probably easier said than done and will definitely take a bit of finesse to get going, but eventually, the bulk should lift away. You’ll then be left with smaller strands which you should then go back over and work at with your scraper.
Pro Tip: You can buy special tools that are specifically shaped for removing sealant and made from plastic to prevent surface damage.
The video below demonstrates this method perfectly:
Using gloves, apply a liberal amount of specialist sealant remover over your existing silicone. You should leave the sealant remover on the area for the recommended amount of time shown on the tub, usually between 2-24 hours. During this time the chemical will break down the sealant and it may swell in size or become a little mushy.
If the sealant remover has worked properly, you should be able to remove the bead of sealant by simply pushing it away from the surface with a plastic scraper without too much extra work.
If there are any smaller strands left behind, you can either reapply the specialist remover and repeat the process or use a scraper to lift the remaining off. Make sure to clean the surface from any chemical residue when you finish.
YouTuber ‘The Ultimate Handyman’ Shows us how easily it’s done with sealant remover here:
There are several different silicone sealants available, each with a special formulation for a certain type of use. When using silicone in a bathroom, you should buy a sanitary silicone that includes a fungicide for prevention against mould.YouTuber Charlie DIYte also suggests in this video to consider how much flexibility your silicone sealant will need (ie, does the surface it will sit upon have a lot of movement?) and choose either a low-modulus (more elastic) or high-modulus (less elastic) silicone based on this as well.
Pro Tip: You can also buy silicone colour-matched to grout for a perfect blending in amongst tiles.
Firstly, clean down the surface with some methylated spirit and a cloth. This will degrease the area so there won’t be any issues that may affect the adhesion of the new silicone sealant.
To release the silicone from its tube, you’ll need to cut the end of the nozzle with a sharp knife. If you wish to apply a thick silicone bead, cut further up the nozzle to create a wider hole. Some silicone tubes may also require you to remove the nozzle and cut off the top part of the tube as well.
Insert the tube of silicone into an applicator gun and as you gently push on the handle, silicone will begin to push out from the nozzle.
Working at a slow and steady pace, apply the silicone in a line straight across the gap you wish to seal. Make sure not to leave any gaps as you do this and don’t worry if it looks a little messy at this stage.
Pro Tip: When sealing around a bathtub, fill the tub with water so that it’s properly weighted (as it would be when in use) to ensure the seal doesn’t crack later.
In order to smooth the sealant to a professional finish, we recommend purchasing a sealant smoothing tool as this will allow you to achieve a perfectly consistent finish, all the way around.
Working in small sections, pull the smoothing tool along the bead of sealant, wiping away any excess from the tool as you go. You’ll notice a smoothly curved seal will be left behind as you pull the smoothing tool across. You may need to go over the silicone a couple of times with the tool for the perfect finish.
Pro Tip: You can spray a mix of water and washing liquid onto the silicone to provide a slippery surface for easier smoothing over with the tool.
Whilst some may argue that you can smooth silicone out with your finger, we actually wouldn’t recommend this. Not only will this create an inconsistent finish, but it may also leave bacteria amongst the silicone which will, therefore, make it more prone to mould.
Sounds obvious, but it’s really important to prevent the silicone from coming into contact with water until it’s completely dry, otherwise this may affect the adhesion as it dries. Some silicone sealants can take up to 48 hours to dry, so if you’re likely to need a shower or bath within that time, make sure to pick a fast-drying silicone first!
For a very in-depth video tutorial on applying silicone sealant, we recommend checking out this Complete Guide, from YouTuber, Charlie DIYte:
So that’s everything you need to know covered. Hopefully, you now feel confident to tackle the job of removing and replacing silicone sealant yourself. It’s a great place to start if you’re new to DIY and it’s a job that can make all the difference.
If this guide has been helpful, please do share it, and let us know in the comment below how you got on!
Kezzabeth is a blogger and DIY renovator. She bought her first house at 20, realising the only way she would be able to get onto the property ladder was to buy a fixer-upper and learn how to renovate, DIY-style