Higher quality underlays give better protection

The huge variety of underlays means choosing the right one is more important than ever.

When working at heights we all know we need to install scaffolding at the eaves for safe entry and exit and ensure the appropriate fall arrest or collective protection systems are in place –preventing falls is front of mind for all of us working at heights.

However, we also need to be vigilant when it comes to avoiding falls through the rafters. As a solution, you can board out the inside of a roof, insert air bags or install safety nets. Even with these solutions available, falls from height still account for one in four deaths in the construction industry, with a misplaced confidence in the strength of vapour permeable underlays (VPUs) sometimes leading to complacency.

The introduction of VPUs instantly made roofs a safer place as they were less than half the weight of traditional underslating felt and clean to handle. Yet, in reality, very few can withstand the weight of an individual if he loses his footing. The huge variation in their quality and strength is also often ignored; we expect them all to provide a similar level of performance when actually, they don’t. If you look at how products have been made increasingly lighter, you’ll often find several areas of compromise, with reduced product strength being the commonest factor.

This has been masked by BBA certificates which suggest that cheaper products are like-for-like with better ones. The answer is simple – they aren’t! If you want to gauge a product’s strength, look at its weight per square metre. As a general principle, the lower the weight, the lower its strength.

A four-layer, high performance VPU such as Klober Permo® Forte presents no such risks. This is one reason why it is still so widely preferred by roofers and specified by architects. A mesh reinforcement as part of its four-layer construction adds strength that’s missing from its 2-layer counterparts. The addition of edge tapes to seal laps in Permo forte SK2 has also given added value, particularly when you are installing an airtight roof.

Safety was a prime consideration in the product’s development and the millions of square metres installed over more than twenty years provide proof of its effectiveness. Don’t fall for anything less.