TLX Insulation Ltd. has been setting standards of excellence in high performance breathable membranes and building insulation for nearly 25 years. We’ve now used our knowledge and expertise to create TLX Batsafe – the bat friendly, energy-saving breather membrane.
Bats are a protected species in the UK and play an important role in the ecosystem. Until now when bats are found, only Bitumen 1F felt has been used. This has come at considerable cost to the thermal performance of the roof because 1F felt requires extra rafter space if insulation is used; in old buildings this is often not possible.
Properties with an uninsulated 1F felt roof can release up to 10 tonnes of CO2 per year. Replacing 1F felt with a breathable membrane and additional insulation between the rafters can improve thermal performance by up to 87% and reduce CO2 emissions by 57%. These factors have a large impact on global warming and climate change. TLX Batsafe is designed with a bat mesh protection system on both sides of the membrane. Unlike 1F felt, TLX Batsafe is breathable, lightweight, high strength and easy to handle. BatSafe is intended for areas where there is evidence of bats and should not be used where roosts are found.
How To Install
Which legislation is relevant for bats and roosts?
- England and Wales, the legislation is the Wildlife and Countryside Act (1981) (as amended); the Countryside and Rights of Way Act, 2000; the Natural Environment and Rural Communities Act (NERC, 2006); and by the Conservation of Habitats and Species Regulations (2010)
- Scotland, the legislation that applies is the Conservation (Natural Habitats &c.) Regulations 1994 (as amended)
- Northern Ireland bats are listed under Schedule 2 of the Conservation (Natural Habitats etc) Regulations (Northern Ireland) 1995 and in the Republic of Ireland, under Schedule 5 of the Wildlife Act 1976 and Schedule 1 of the European Communities (Natural Habitats) Regulations 1997
Who should take note of the legislation?
- Architects, property developers, demolition companies, builders and roofers
- Property owners/householders who have a bat roost in their property
- Woodland owners, arboriculturalists and foresters; information about woodlands and bats
- Pest controllers. Information about bats in buildings
- Planning officers & building surveyors
Test Report Overview
Bats are a protected species in the UK and play an important role in the ecosystem. Until now when bats are found, only Bitumen 1F felt has been used. This has come at considerable cost to the thermal performance of the roof because 1F felt requires extra rafter space if insulation is used; in old buildings this is often not possible. Properties with an uninsulated 1F felt roof can release up to 10 tonnes of CO2 per year. Replacing 1F felt with a breathable membrane and additional insulation between the rafters can improve thermal performance by up to 87% and reduce CO2 emissions by 57%. These factors have a large impact on global warming and climate change.
Bats and breather membranes
In 1997 we invented the three-layer breather membrane. This technology is now used across the UK because it significantly reduces carbon emissions from dwellings.
In 2013 we became aware that our technology was causing a problem for bats. We contacted a PhD student, Stacey Waring, to find out more. She brought us samples of material which demonstrated that the nonwoven fibres used in the construction of the product (the fibres are half the width of a human hair) could be broken by bats and fluffed up.
Some kind of protective layer, such as a net, to prevent bats getting access to the nonwoven seemed to be the answer but it’s size and dimension needed to be determined. Stacey offered to undertake sponsored research at a bat hospital. This work gave us answers on net mesh size (2 – 6mm). This would not only reduce access to the nonwoven by the bat but also maintain the breathability of the roofing underlay. We now needed to identify a net suitable for both roofers and ecologists.
We undertook trials of different nets using various adhesives. Stacey recommended woven glass fibre as being a suitably strong material but, unfortunately, its weight and cost made it impractical. We had the same problem with many of the nets we trialled.
It was during this work that we noted that fibre breakage of the nonwoven did not necessarily lead to fluffing. It was the fact that there was no restraint on the bat’s ability to tease the fibre out that was the problem. We solved this by developing a sheet of breathable adhesive, which we laid down between the net and the nonwoven, thereby limiting any fibre breakage to the dimensions of each mesh square ( <3mm ). We now had two barriers to fluffing up; the net itself, and also a limit to the length of a fibre. How could this be tested?
Three tests were required to convert our bat hospital results into a test method to ensure industrial quality control:
• The net. We adapted ISO 105 X12:2016 as a method for ensuring the abrasion resistance of the net was according to our specification
• The breather membrane. We found that a 3mm mesh size would not impede the breathability of the roofing underlay but would restrict access to the nonwoven material by the bat. Luckily, Stacey had already undertaken some helpful work in this area. By modifying a test method used by the textile industry to measure pilling (ASTM D3512 measures fibre breakage) Stacey had already modified this test method, so that it replicated the ‘plucking’ action of bats. She estimated that 3000 rotations of the pilling machine would replicate bat activity for approximately a year. We ran this test for 75,000 cycles ( this represented the 25 year life of a roofing underlay). There was no evidence of fluffing of the non woven layer.
• Batsafe. The whole structure was subjected to an aging test (EN13859-1:2010) to ensure that the finished product would still be structurally sound having been exposed to high roof temperatures over a long period of time
How safe is BatSafe?
Since innovation always precedes regulation it is inevitable that there is a period when products are commercially available before independent test protocols are established. During this period the consumer must be guided by evidence-based information along with trust in the efficacy and experience of the company developing new products. TLX Insulation Ltd has some experience in this area having developed test methods for evaluating the performance of new roofing materials that have subsequently been adopted by international bodies.
On the basis of our research, experience and testing, it is our view that BatSafe will reduce the risk of bat/fibre entanglement. BatSafe is intended for areas where there is evidence of bats and should not be used where roosts are found.
|TLX BatSafe has been tested using the industry recognized Pilling Test method BS EN ISO 12495-1:2001, to measure its anti-fluffing properties. The Pilling Test was used to test the anti-fluffing of the product across its whole structure. The test was terminated at 75,000 rotations or before the fibre length exceeded 3mm.|
|Standard Breathable Membrane|
Filament strand thickness test
|Test to determine the filament thickness difference between a nonwoven breathable membrane and TLX BatSafe mesh.|
|Average breather membrane filament strand thickness|
|Characteristic: Strand||Value: 15µm|
|Average TLX BatSafe mesh filament strand thickness|
|Characteristic: Strand||Value: 790µm|
The functional breather membrane is CE-marked in accordance with harmonised European Standard BS EN 13859-1 : 2010
|TLX BatSafe Technical data|
|MD Tensile Strength||380||N/50mm|
|CD Tensile Strength||240||N/50mm|
|MD Nail Tear (CE)||214||N|
|CD Nail Tear (CE)||290||N|
|MD Tear Strength||166||N|
|CD Tear Strength||228||N|
|Hydrostatic Head||>200||cm H2O|
|Water Vapour Transmission (Sd)||0.019||m|