A quick trip to the local hardware store to pick up a few tubes of sealant for the job may not be as straight forward as that – when you get there, you’ll probably be faced with a huge floor to ceiling shelf fully stacked with a range of sealing products.
While the expansive choice can initially seem a bit overwhelming, if you know what to look for, you can soon cut through and find exactly what will work best for the application.
As a starting point, you need to choose a sealant that’s been specifically designed for use with metallic coated and prepainted steel products, that means finding a ‘neutral-cure silicone’. This type of silicone is proven, having successfully been used on a range of coated steel surfaces, from roofing and walling through to steel flashings, cappings and gutters for many years.
So what makes neutral-cure silicone sealants different to other silicone sealants on the market?
The important difference is that some silicone sealants have an acidic additive that gives off an aggressive by-product during curing, which can damage the metallic and/or prepainted coating on many steel cladding, rainwater and even structural products. These sealants often have a vinegar or ammonia type smell, but the best way to know if the sealant is compatible, is to check the label.
The benefits of using neutral-cure silicone sealants:
- Will not damage the metallic and/or prepainted coating
- Will provide good adhesion to the steel surface for both roofing and walling applications
- Are resistant to cold and heat while retaining good flexibility
- Will offer strong resistance to ultra-violet rays
- Are excellent gap fillers
- Have a long service life
Remember though, that most sealants are not adhesive, so the steel will still need proper fixing.
Also, if the silicone will be visible and post painting is needed, ensure that the natural-cure silicone you choose is paintable. It is possible to paint over standard natural-cure silicone but this requires more work, as the surface needs to be abrased to allow the paint to adhere. Multiple coats of paint will be needed to ensure good coverage, and the process also requires a steady hand so the steel surface isn’t damaged during paint preparation.
For more information, contact Lysaght direct on 1800 641 417