There is a growing need for the construction industry to become more environmentally aware, which includes considering solvent emissions, recycling and toxicity, and building materials supplier DenBraven national sales and marketing manager Michael Berg says the company has made higher performance hybrid sealants available to industry to assist.

“The development of new construction materials and stricter building regulations has given rise to a need for higher-performance sealants. As a result, our Hybriflex 540 is a high-quality professional universal low modulus sealant based on hybrid silyl modified polyurethane (SPUR) technology.”

The Hybriflex 540 – also suitable as a weather and perimeter sealant – is a joint sealant for sealing construction and dilatation joints. It can also be used for joints in pedestrian walkways on most common building materials such as concrete, brickwork, painted wood, enamel, aluminium and stainless steel.

Berg further notes that the sealant includes the EN 15651-1: F-EXT-INT-CC 25LM and EN 15651-4: PW-EXT-INT-CC 25LM certifications, which ensures that sealants are suitable for façade elements and for pedestrian walkways.

“The Hybriflex 540 boasts perfect adhesion without primer on most substrates even on damp surfaces, and it has almost no shrinkage on cure and doesn’t bubble,” Berg enthuses.

He adds that the product is permanently elastic, with a 25% movement capability and high mechanical resistance, and is – in most cases – easier and quicker to work with.

“It also has better shelf life and is paintable with water-based and most two- component paints. The Hybriflex 540 is available in cartridges or 600 mℓ foil packs.”

However, Berg further notes that the sealant performance generally depends on the correct engineered joint designs, and applicable substrates as surfaces and expansion coefficients vary.

The correct application of the product – as well as environmental conditions – can also play a role, as the curing of the hybriflex is temperature and humidity dependent.

“Substrates which the sealant is applied to must be clean, as well as dry, dust, grease and oil free,” he says, noting that for floor and wall joints in particular, the correct joint dimensions are required.

These dimensions, he notes, include the ratio of a joint depth to the width. For widths up to 10 mm, a 1:1 ratio can be used, with the minimum width being 5 mm. For joints wider than 10 mm, the joint depth should be half the joint width – 2:1.

A suitable, well-fitting backing cord should be used to control the joint depth and ensure two-sided adhesion.

“Our research and development departments, together with research institution the Centre of Excellence, are constantly working on product improvements and advance sealant formulations,” Berg concludes.