Roofing underlays

LETO 145

LETO 145 is a BBA-certified, vapour-permeable roofing underlay developed for pitched roof applications where increased strength and durability are required. Manufactured from a robust three-layer polypropylene construction, it delivers enhanced tensile performance, W1 water resistance and excellent vapour-permeability, helping to protect the roof structure while reducing the risk of condensation. Suitable for warm and cold roof constructions, LETO 145 offers a balance of strength, performance and value for a wide range of residential and commercial roofing projects.

Solar
Compatible
Vapour
Permeable
W1 Resistance to
Water Penetration
Resists Wind
Uplift
UV Stable
3 Months
UK wind zones map

Wind Zones

Taped laps 1-5
BATTENED LAPs 1-5
BBA CE UKCA

Technical Specifications

Weight, gsm 145
Resistance to water penetration, Class W1
Water vapour transmission (Sd), m 0.02
Tensile strength (MD/CD), N/50mm 300 / 200
Elongation at max. tensile force (MD/CD), % 60 / 100
Nail tear resistance (MD/CD), N/50mm ≥50 / ≥50
Flexibility at low temperature -40°C
UV stability, Months 3
Reaction to fire, Class E
Colour Grey

Ideal For

  • Warm roof construction
  • Cold roof construction
  • Vented and unvented roof systems
  • Timber frame and rafter roofs

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Documents & Downloads

BBA Ceritficate - For use in cold non-ventilated pitched roof systems

BBA Ceritficate - For use in warm roof and cold ventilated pitched roof systems