If you’re an avid DIY-enthusiast, you are bound to bump into a mastic sealant at some point. Used as a bond, it’s a waterproof material that seals cracks and helps to protect household fixtures and fittings.
As GT Sealants, the mastic sealant specialist, we will answer the most important questions to find out more about mastic sealant and the pros and cons of using it for DIY projects. With more than 20 years in the trade, we get asked various questions on sealants so this complete guide details everything you need to know.
What is Mastic?
It’s a sealant that is elastic and flexible when applied to surfaces. As a result, it’s perfect for as a bond for attaching different materials and filling gaps. An excellent example is sealing the bathtub. Waterproof mastic silicone brings the wall tiles and porcelain (or whatever your bath is made from) together to ensure there are fewer leaks when the area is wet. Another example is connecting wooden or plastic window frames to your property’s structure.
What is Mastic Sealant Made Of?
Mastic sealant isn’t made from one single material. The term is commonly used to describe a range of flexible sealing products, and the formulation will depend on where and how the sealant needs to perform. Products used in the trade can be based on silicone, acrylic, polyurethane and other polymer technologies.
In our experience working with sealants, we know that choosing the right product is just as important as applying it correctly. Different formulations offer different levels of flexibility, adhesion, weather resistance and moisture resistance, so the right sealant should always be selected for the surface, joint and environment.
What is Mastic Sealant Used For?
Mastic sealant is used to seal joints and gaps between different surfaces, helping to prevent water, air and, in certain applications, sound from passing through. You’ll commonly find sealant around windows and doors, sanitary fittings, kitchens, flooring, skirting and other internal and external joints.
What Materials can Mastic Sealant Be Used On?
The simple answer is that it is an all-purpose tool that attaches to pretty much every material. As well as wood and tile, it works on the following:
- Aluminum
- Glass
- Marble
- Duct board (and much more)
As a result, it’s a standard application for people who prefer to do it themselves rather than use professionals. Still, paid contractors use mastic sealant, too, due to the fact it is flexible and strong. So, whether you’re a novice or an expert, it’s a tool that is used across the board, making it an incredibly popular partner for household and commercial tasks.
Also, life expectancy is very high. Once you apply mastic silicone, you can expect it to stay in place for up to five years before it requires replacing.
What Are the Different Types of Mastic Sealant?
After more than 20 years working with sealants, one thing we’ve learned is that “mastic” can mean different things depending on the job. There are several sealant formulations available, and understanding the differences is important when choosing a product.
Silicone sealant is one of the types we use where flexibility and moisture resistance are required, such as around sanitaryware, kitchens and glazing.
Acrylic sealant is more commonly suited to internal finishing and gaps where a paintable surface is useful.
Polyurethane sealant can be appropriate for more demanding construction joints where adhesion, durability and movement need to be considered.
There are also specialist polymer sealants designed for particular substrates and performance requirements.
The key is matching the product to the joint. A sealant that performs well around a bath, for example, isn’t automatically the right choice for an external building joint exposed to weather and regular movement.
The Pros & Cons of Mastic Sealant
The fact that mastic sealant is long-lasting and is applicable to most materials is only the tip of the iceberg. Below, you’ll find a range of pros and cons to help you make an informed decision when it comes to purchasing sealant.
Pros
- Little Preparation Is Required
Because it doesn’t need a primer, you can apply mastic silicone right away, as the area is dry. Waterproof sealant can’t get wet or else the adhesive won’t work correctly. Still, if the surfaces are dry, very little prep is required before pasting it on with a gun.
- It’s Useful Outside
In-house projects are important, but you shouldn’t forget your exterior, either. Unsecure gutters, for instance, will burst and cause leakages inside as well as outside your home. Thanks to its waterproof properties, a mastic sealant is useful for outdoor tasks, too.
- Mastic Sealant Looks Great
Part of repairing your home is making it appear homely. And, while this silicone is thick, it’s also smooth. Therefore, it adds a stylish and rugged design while maintaining its practicality.
Cons
- It Can’t Handle Movement
Constant movement causes chips and cracks in the sealant’s structure. So, you shouldn’t put it somewhere there is lots of pressure.
- Works Better When Applied Generously
As a result, it’s not recommended if you only have a small gap to fill as it can be more stressful than effective.
Where Can You Buy Mastic Sealant?
Mastic and other sealants are readily available from DIY retailers, builders’ merchants and specialist trade suppliers. For smaller household jobs, you’ll usually find products designed for common applications such as bathrooms, kitchens, windows and general internal sealing.
The important part is knowing what you’re buying. Having worked with sealants across a wide range of applications, we’ve seen that choosing the wrong product can be just as problematic as poor application. Check what surfaces the sealant is compatible with, whether it’s designed for internal or external use, its resistance to moisture and weather, and whether it can accommodate the expected movement of the joint.
For specialist construction work, product selection will often be determined by the requirements of the project rather than what’s most readily available.
How Can GT Sealants Help You?
Mastic and sealant work can range from finishing joints around kitchens and bathrooms to extensive sealing requirements across commercial developments. Whatever the scale of the project, the product needs to be correctly specified and professionally applied if the joint is to perform as intended.
With more than two decades in the trade, GT Sealants works on residential and commercial projects throughout Cambridge, Essex, London and other areas across the UK. Our experience includes working alongside major building contractors on multi-million-pound projects, as well as completing specialist airtight and acoustic sealing work.
Contact GT Sealants to tell us about your project and find out how our experienced team can help.
