Performance and practicality sealed with Arbosil LMS

While the only predicable feature of a British summer is that its notoriously unpredictable, recent weeks have seen the weather warm up and brought us a break in the rain, which can only mean one thing for the fenestration sector – it’s peak time for installations!

With energy bills still high and homeowners keen to reduce both their carbon footprint and the heat escaping their property, replacement windows and doors, or upgrades to the existing, are a popular home improvement. Selecting the right sealant is critical to delivering a project that not only looks great but supports the quality of the installation for an extended service life.

Arbosil LMS is one of the fenestration industry’s most trusted silicone sealants, and in this article, we will explain why, as well as showcasing the new colours that align with evolving tastes in home décor and contemporary glazed unit profiles.

What is Arbosil LMS?

One of our most recognised and widely used sealant systems, Arbosil LMS is a single component, neutral cure silicone sealant. Unlike acetoxy silicones, which release acid while curing, Arbosil LMS neutral cure formulation means it is virtually odourless, making it more pleasant to work with and more suitable for use in occupied buildings, whether the occupants are residents, workers, or contractors.

Arbosil LMS cures on exposure to moisture vapour, which means it begins to cure due to ambient moisture as soon as it has been applied, without the need for any heat, UV or other accelerants to begin the curing process. It is also a low modulus (LM) silicone sealant, which means it forms an elastic silicone rubber seal with excellent resistance to being stretched. This makes Arbosil LMS an ideal silicone sealant for moving joints, such as window frames or expansion joints, and it is often used for perimeter sealing of PVCu frames, as well as glazing, insulating glass units, and remedial glazing.

What makes Arbosil LMS so popular?

The key to  Arbosil LMS’ enduring popularity is the benefits it provides for both the installer and the project

Available in a choice of 14 colours – translucent, white, black, grey, RAL 7016, RAL 7022, light grey, anthracite, brown, buff, dark bronze, portland, rustic red, and magnolia – Arbosil LMS combines specification choice with excellent resistance to most dilute acids or alkalis, which may be contained in cleaning products, and an extended service life of 25+ years. This means that the finished installation benefits from a pleasing aesthetic and low maintenance for a lifespan equal to that of the glazed unit.

For the installer, Arbosil LMS is a very practical option. The silicone sealant has a shelf-life of 12 months if stored in a cool, dry place out of direct sunlight in its original, unopened packaging, and it can be applied successfully at any temperature between +5⁰C and +40⁰C, giving it year-round suitability for UK projects.

With a skin time of just 10 minutes, Arbosil LMS has a cure rate of 2mm/24hours at 20⁰C with 65% relative humidity.

Exceptional performance

For those specifying or procuring silicone sealants, performance matters, because the sealant is such an important element in avoiding call backs or warranty claims. Arbosil LMS not only offers a 25+ year service life; it also delivers exceptional performance.

With a Shore A hardness of 30, Arbosil LMS provides an ideal combination of durability and elasticity, which makes it resistant to impact, abrasion, and weathering, while enabling sufficient flex to cope with movement, including 50% butt joint movement in tension and compression, and 100% lap joint movement in shear. With excellent UV resistance, Arbosil LMS retains its durability and elasticity within the temperature range of - 40º C to + 120º C - far beyond any climate conditions it will be subjected to, and even providing resilience in the event of a fire.

In order to achieve Arbosil LMS’ full performance capabilities, it is essential to prepare the joint surfaces, which should be clean, dry, and free from all contaminants. This can be done with the use of the appropriate Arbo cleaner. For some substrates, an ARBO primer may be required, and our technical team can advise on whether this is necessary, and which primer is best suited to the application.

Where appropriate, a joint filler, such as a closed cell polyethylene foam, should be used to provide the correct joint depth. Arbosil LMS can be applied into the joint using an ARBO caulking gun to release the silicone sealant from its polyethylene cartridge. All joint preparation, priming, and sealant application should be carried out in accordance with BS 8000 Part 16 BS 8000-16:1997+A1:2010 (the British Standard code of practice for sealing joints in buildings), and use of Arbosil LMS is not recommended for overpainting, glass wall assemblies, or against natural stone. 

As with all our sealant and façade systems, our technical team are on hand to provide support from specification through to site to maximise performance and minimise waste. If you have any questions about Arbosil LMS, talk to an expert in your area.

For easy specification find Arbosil LMS on NBS - https://source.thenbs.com/product/arbosil-lms/3HmDPxi7bv7d73VZ4qxD6Q/o1BNoTgAzxUbpbDyhGUPqM