Silicone sealants were first used to bond glass panels to skyscrapers — a far more demanding job than most home improvement projects. They stay flexible at all temperatures, are completely waterproof, bond well to almost everything and won’t support mildew growth. Silicones are used around sinks, tubs, shower stalls and window frames.
These sealants have developed into indispensable, versatile products for an extremely broad application range: whether on building sites, in the field of sanitary applications and fittings, window construction, metal or plastic construction, in the household or DIY sectors – silicone sealants are used everywhere. They contribute to long-lasting quality, obtained in a particularly quick and easy manner.
Silicones come in two types: neutral cure or acid cure. Acid-cure silicones work best on non-porous surfaces such as glass and glazed tile, but they can corrode metal and etch some plastics, whilst neutral-cure silicones work well on metal and wood.
It’s all about performance and silicone sealants are the reliable way to seal joints against the elements. Unlike other joint fillers, silicone sealants have the best resistance to weathering and ageing – lasting for up to several decades. Not even years of open-air weathering will change their physical properties.
In addition to their resilience and reliability, they cushion movements between parts resulting from temperature changes, humidity, shrinkage of construction material, sound, wind and other mechanical shocks.
Silicone sealants also have extreme temperature resistance as the elastic properties of silicone sealants stay almost constant between -40 °C and +100 °C. This is a major advantage over sealants made of organic polymers.
These key features make silicone sealant reliable, versatile and perfect for jobs around the home, particularly for weatherproofing as the winter months approach.
How to use a Silicone Sealant: Sealing a Window Frame
This is the perfect time of year to check your window seals as you don’t want your house to leak air, especially if you spend your hard-earned cash warming it. Test a window for leaks by burning an incense stick near all its joints and connections and, if the smoke flickers, you have an air leak. The most likely places for a leak to appear are:
- Where one section of the window meets another
- Where the windows meet the frame
- Where the frame meets the wall
Silicone rubber sealant is an excellent way to stop draughts entering around windows. First, to ensure you apply an even bead of silicone rubber sealant, apply masking tape to form edges for the sealant. Put a single long strip on either side of the join where you’ll be applying the sealant and this will keep the sides of the sealant neat on the window frame.
Cut your sealant spout at an angle to make application easier, then squeeze out a smooth, even bead of silicone rubber sealant along the window, keeping a low, even pressure. Run the tube slowly along between the masking tape.
Don’t try and run sealant around the entire window in one go – it’s much better to do one side at a time. This means you’ll be able to work without risking the silicone rubber sealant drying out.
Once you have the bead of sealant on the window, you’ll need to smooth it out. To do this, dip your index finger in soapy water and run it along the bead of sealant. Ideally, you should be able to go all along in a single motion but this won’t always be possible. If multiple strokes are needed, try to use as few as possible and always go in the same direction. The idea is to make the line look completely smooth, so where different sides of the frame meet, smooth down the join with your fingertip.
When you’ve done this, leave the silicone rubber sealant to dry completely then pull off the masking tape. This should remove any uneven edges on the sealant, but if any remain, even them up with a razor blade or utility knife.