Mastic asphalt screed is a dense, seamless and waterproof material used to create level bases for roofs, balconies, terraces, walkways and vehicle decks. It provides a stable platform for drainage falls and finishes, making it suitable for both new build and refurbishment projects.
Mastic asphalt screed can be laid and cured quickly, cooling in approximately one day compared to the usual 28-day curing time of concrete screeds. This speed, combined with the fact that it holds no water content, provides a reliable surface ready to receive waterproofing systems or other finishes without delays on-site.
IKO Permascreed LI combines the trusted reliability of mastic asphalt screed with modern innovation. It supports faster installation and lowers environmental impact for today’s construction needs with its reduced embodied carbon of up to 38%.
Why choose IKO mastic asphalt screeds?
IKO mastic asphalt screeds are designed to simplify construction while ensuring long service life. They:
- Provide a seamless, waterproof and voidless base that levels uneven surfaces.
- Form drainage falls, ensuring water drains away quickly and efficiently.
- Contain zero water, eliminating curing delays and making it more environmentally responsible.
- Are lightweight compared to traditional concrete screeds, reducing thickness by up to 80%.
- Require no compaction and are ready for use as soon as they cool to ambient temperature.
- This faster, simpler workflow helps keep projects on schedule, reduces overall build-up weight and provides compatibility with a wide range of roofing and waterproofing systems.
Drainage falls are designed in line with BS6229:2025, supporting compliance across a wide range of applications. Every system is manufactured in the UK at sites certified to ISO 9001, ISO 14001, ISO 45001, BES 6001, and PAS 2080 standards.
As active members of the Mastic Asphalt Council (MAC), IKO upholds rigorous quality assurance across its full mastic asphalt range, while contributing to the development of industry standards and technical best practice.
“This is the first time I have been involved in a project incorporating IKO Permascreed. I have been really impressed at the speed and ease in which it is installed to form drainage falls. There is no curing time so the flat roof waterproofing works can follow on immediately. It’s a real time saver!”
Jamie Jones
Package Manager
Sir Robert McAlpine Ltd
Mastic asphalt screed
IKO Permascreed LI
- Up to 38% lower upfront embodied carbon.
- Zero water content means no curing requirements.
- Suitable for levelling uneven flat roofs to eliminate back falls and deflections.
- Creates a wide range of drainage falls.
- Can be walked on and waterproofed once cooled.
- Compatible with a wide range of waterproofing systems.
Mastic asphalt screed
IKO Permascreed H (Heavy Duty)
- Designed for use on car parks and HGV service decks.
- Zero water content means no curing requirements.
- Suitable for levelling uneven flat roofs to eliminate back falls and deflections.
- Creates a wide range of drainage falls.
- Can be walked on and waterproofed once cooled.
- Compatible with a wide range of waterproofing systems.
IKO Permascreed LI: Fast-tracking performance and sustainability
IKO Permascreed LI is a mastic asphalt screed designed to reduce upfront embodied carbon while delivering long-term performance
- Third-party EPD – showing a 73.44kg CO₂e reduction per tonne compared to its predecessor.
- Efficient installation – lighter build-up and rapid curing keep both new build and refurbishment projects on schedule.
- Long service life – proven with a design life of more than 60 years.
- Sustainable by design – developed in line with IKO’s Science-Based Targets, supporting a 42% Scope 1 and 2 emissions reduction by 2030 and net zero by 2050.
- Part of the IKO LI range of low-impact systems, IKO Permascreed LI is fully compatible with IKO Permatec LI, the UK’s first carbon-storing hot melt waterproofing solution.
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IKO in action
Broadmarsh Shopping Centre
Water was leaking into the shopping centre from exposed areas above. IKO Permascreed was used locally to bring levels up and direct water towards outlets, providing flexibility around intricate support structures. The installation successfully stopped water ingress into ancient sandstone caves below the site.
