Description
Larsen DuoMat 360 is a low-profile, 2-in-1 anti-crack and decoupling membrane for floor tiling. Supplied as a 30m x 1m roll (30m²), it sits between the substrate and the tile bed to absorb lateral movement and stress, helping to stop cracks in the floor below from transferring through to your tiles. At just 0.7mm thick it adds less than 1mm to the floor build-up, making it a practical choice for professional tilers, bathroom fitters and builders working over timber floors, heated screeds and cracked subfloors.
Key benefits
- 2-in-1 anti-crack and decoupling – accommodates lateral substrate movement and protects the finished tiling
- Minimal height build-up (under 1mm) – no awkward thresholds or door trimming
- Uses less adhesive than traditional 'waffle'-type decoupling mats
- Fast-track installation – tile as soon as the bedding adhesive has set
- Printed 50mm grid for quick, accurate measuring and cutting with scissors or a knife
- Ideal with underfloor heating
- Suitable for commercial and domestic projects
Applications
DuoMat 360 is designed for floors only and is ideal beneath ceramic, porcelain, large format and natural stone tiles. Typical uses include:
- Timber floors (minimum 15mm flooring-grade sheet material, screw-fixed at 300mm centres)
- Heated floors and underfloor heating screeds
- Floors with hairline cracking or limited movement
- Gypsum-based (anhydrite) screeds, once dry, mechanically prepared and primed
- Kitchens, bathrooms, hallways, extensions and commercial floor areas
Performance & features
- Roll size: 30m x 1m (30m² coverage)
- Thickness: 0.7mm
- Weight: 0.2kg/m² (approx. 6kg per roll) – easy to carry and handle on site
- Elongation: 40% longitudinal, 33% lateral
- Colour: white with blue measuring grid on the top face
- Shelf life: minimum 24 months in unopened packaging
How to install
- Make sure the floor is solid, rigid, stable, level and free from dust, grease and loose material.
- Roll out the mat, measure and cut to size using the printed grid, then roll it back up.
- Apply a flexible fast-setting tile adhesive to the substrate with a 4x4mm notched trowel.
- Roll the mat into the wet adhesive and smooth it down with the flat edge of the trowel, removing any air pockets.
- Once the adhesive has set, tile directly onto the mat – a flexible rapid-set adhesive is recommended. Take care not to de-bond the mat while tiling.
Carry all expansion and movement joints up through the mat and the tiling. Do not install below 5°C, and keep the area above 5°C for 24 hours afterwards.
Compatibility
- Use with flexible cement-based tile adhesives such as Larsen Professional Fibreflex Rapid Set+
- Gypsum-based screeds must be below 0.5% moisture content, mechanically prepared and primed with two coats of Larsen Acrylic Primer (first coat diluted 1:1 with water, second coat neat)
- Floors with excessive deflection should be over-boarded with tile backer board or minimum 15mm plywood first
- Not suitable for walls, or over soft bituminous materials, oil or grease
Technical specifications
- Brand: Larsen
- Product: DuoMat 360 Anti-Crack & Decoupling System
- Roll size: 30m x 1m
- Coverage: 30m² per roll
- Thickness: 0.7mm
- Weight: 0.2kg/m², approx. 6kg per roll
- Elongation: 40% longitudinal / 33% lateral
- Colour: white with blue 50mm grid
- Use: floors only, internal
- Minimum application temperature: 5°C
- Hazard information: no significant hazard
- Storage: dry conditions, protected from extremes of temperature
- Shelf life: 24 months minimum, unopened
- Pack quantity: 1 roll
What's included
1 x Larsen DuoMat 360 Anti-Crack & Decoupling Matting roll, 30m x 1m (30m²). Tile adhesive and primer are sold separately.
Frequently asked questions
What does a decoupling mat actually do?
It separates the tile bed from the substrate so that lateral movement, shrinkage and hairline cracks in the floor are absorbed by the mat rather than passed into the tiles and grout.
How much height does DuoMat 360 add to the floor?
The mat is 0.7mm thick, so build-up is under 1mm plus its thin adhesive bed – far less than a dimpled 'waffle' mat.
Can I use it with underfloor heating?
Yes. DuoMat 360 is ideal for heated floors, where thermal movement puts extra stress on the tiling.
Can it be used on timber floors?
Yes, provided the floor is rigid. Sheet material should be at least 15mm flooring grade, screw-fixed at 300mm centres. Floors with spring or deflection need over-boarding first.
What adhesive do I need?
Bed the mat into a flexible fast-setting tile adhesive using a 4x4mm notched trowel, then fix tiles with a flexible adhesive – rapid set is recommended.
Can I use DuoMat 360 on walls?
No. It is only suitable for use on floors.
How much area does one roll cover?
Each roll is 30m x 1m, covering 30m².
Supplied by Millcot – trade tiling and wetroom specialists, with knowledgeable support and fast UK delivery.