We've updated our name! You may know us as SD Sealants, but we now go by SD Team.

We've updated our name! You may know us as SD Sealants, but we now go by SD Team.

United Kingdom

One of the UK’s leading sealant companies to a range of industries

sealant applicator carrying out work on-site

Our team of fully qualified sealant applicators provide comprehensive mastic and sealant services to a wide range of customers and industries. We are immensely proud of the quality of service, attention to detail and professionalism we employ, making us one of the market leaders in the sealant industry.

Internal and external window frames

Our highly qualified sealant applicators provide perfect-finish sealant around the perimeter of wooden, aluminium, and uPVC windows.

Internal and external door frames

Expert sealant application for door frames in any range of materials. Our applicators utilise weatherproof and UV resistant products for exterior doors.

Glass to glass

Our expert team can bond glass pane joints together using products with high resistance to UV exposure and temperature fluctuations.


We assist a wide range of businesses and properties that require expert, perfect-finish sealant to skirting boards, joints and architraves.

Expansion joints

Application of expansion joint sealant, designed to absorb impact and expand or contract across the building envelope without cracking or separating.

Acoustic sound proofing

Our sealant specialists will assist with the application of flexible, long-lasting sealant that doesn’t dry out or shrink and therefore can offer soundproofing qualities to any room for a lengthy period.

Air test jointing

If work is required following an air test, our expert applicators can assess the level of weakness identified and seal jointing appropriately to prevent air flow.

Fire proofing

Our team can apply fire-resistant sealants include technical specifications and fire protection capabilities to help prevent the spread of fire, smoke and toxic gases.

Lead work sealing

Whether it’s roofing joints, gutters, downpipes or venting, our expert applicators can seal lead into a range of materials including brick, stone or concrete.

Floor saw cut joints

We provide flexible sealant solutions for cut joints in a variety of locations including warehouses, forecourts, garages or anywhere concrete slabs are present.

Swimming pools

Qualified to work on both wet and dry areas within a sports complex, our applicators use swimming pool joint sealant and chlorine resistant sealant for pools, as well as antifungal silicone sealant for the surrounding area, changing rooms and more.

Caravan sealant

Instead of removing and replacing entire panels, our team uses a selection of acoustic sealants, clear sealants and specialist window frame sealants to provide a range of solutions which are highly in demand amongst commercial operators in the caravan industry .

Experienced Professionals with Decades of Expertise

Operating for over 50 years, SD are recognised as one of the UK’s largest finishing groups, with multiple offices across the UK. Providing an unrivalled service, SD’s reputation in the sealant industry has been built on providing an unmatched, efficient, meticulous and quality service to everyone we work with.

Sealant services FAQs

If you have any unanswered questions about our sealant application services, please don’t hesitate to get in touch with us at any time – our team will be happy to help.

What is mastic sealant?

Generally speaking, the two main sealing applications are the joining of one surface to another, and providing protective cover to a particular area. Mastic sealant is a type of sealant used in projects where the sealant needs to stay flexible once it’s dried, as it can maintain its durability for years while also bending as required.

Our team commonly uses mastic sealant in construction projects to connect doors and windows to the main structure, as well as in bathrooms to seal the area around tubs or to fill in cracks in masonry. Incredibly versatile, it adheres to a range of materials, including concrete, steel, aluminium, wood and glass.

How is mastic sealant applied?

Regardless of the type of surface you are applying the mastic sealant to, there are a couple of things to remember.

While priming the area before mastic application is not necessary, it’s good practice to ensure that it’s been thoroughly cleaned and dried. As most mastic sealants come in a tube or tub, the best tool to apply them with is the trusted caulking gun. The average lifespan of mastic sealant is approximately five years, so we recommend replacing it after that period to ensure optimal efficiency.

Should I opt for mastic or silicone sealant?

There are a number of unique features which set mastic sealant aside from other alternatives such a silicone. Combining a smooth surface with a rigid form and unrivalled flexibility, mastic sealants are easy to apply, as they come in a pasta shape which applies to the surface smoothly without need for priming.

In our experience in working on different projects, we’ve also found that mastic is perfect for outdoor sealant application thanks to its ultraviolet (UV) inhibitors, which help keep it from weakening in the sun, as well as its waterproof properties and weather resistance. What’s more, unlike some of their counterparts, mastic sealants are great for use on metals, as they don’t cause corrosion.

However, there are also a couple of downsides to mastic sealants to be aware of. Despite its exceptional flexibility, we don’t recommend using it on areas where it will be subjected to extreme join movement, as it will eventually wear down. We also advise using mastic mainly for thick sealant applications such as wider cracks in masonry or large gaps, as it’s not best suited for areas requiring a delicate finish and you may prefer silicone in this instance.

Let’s discuss your next project

Every project that comes through our doors goes through our technical team and allows us to provide bespoke solutions, to meet your exact needs. The first step is a conversation, so please get in touch to find out what the challenge is that you need us to solve.