Python LR


Badge Lr 2

A free flowing, fast setting, fibre reinforced, shrinkage compensated cement based formulation, designed for smoothing and levelling sub-floors prior to the installation of floor coverings.

Buy Now

Product Details

Apply from 2 to 50mm in one pour

Apply tiles after 3 hours

Single part, no additives required

Protein free

Ideal for plywood

Suitable for use with underfloor heating systems

Apply impervious floor coverings after 24 hours

Simply mix with water to use

Technical Specification


Python LR is a fast setting, flexible, fibre reinforced self levelling compound. The specially formulated powder enables the product to be poured to depths between 2mm – 50mm in one application and receive foot traffic after 3 hours.

Python LR has excellent flow and adhesion properties making it suitable for a wide range of both commercial and domestic applications. Python LR is suitable for use over a wide range of substrates including sand/cement screeds, concrete, flooring grade asphalt/bitumen, ceramic, porcelain and terrazzo tiles, epoxy damp proof membranes and plywood.

Python LR is also ideal for encapsulating electric underfloor heating elements and for use over underfloor heated screeds.

Python LR is fast setting, meaning ceramic tiles can be installed after as little as 3 hours, and decorative floor coverings can be installed after 24 hours.

Under certain conditions, Python LR is suitable for use externally. For further information please contact the Technical Helpline on

020 8778 9000 or email for further information.


Before starting, all substrates must be clean, dry and strong enough to support the weight of the leveller and the final floor covering being applied. Remove all dust, dirt, oil, grease and other contaminants that may affect adhesion. Where traces of adhesive residue remain, these must be checked to ensure that they are not softened with water and that they are strong, sound and well adhered to the substrate in order to receive a levelling compound.

The substrate must be confirmed dry by consistent moisture readings; <75% relative humidity (RH) or <0.5% residual moisture content prior to starting. Where a structural damp proof membrane is not present or where rising damp and/or residual moisture results in moisture readings up to 98% RH, a liquid damp proof membrane such must be applied before the application of Python LR. Surface laitance should be removed from concrete and sand/cement screed surfaces prior to application.

Substrates require priming prior to the application of Python LR. Priming the substrate will minimize the risk of pinholes forming, allow for the best flow properties and also prolong the working time of the product. Priming the substrate prior to application is considered “best practice”. For recommended priming dilution rates please refer to Page 3 of this data sheet.

Prior to levelling timber substrates ensure that timber boards are securely screwed down and firmly fixed. Where timber substrates are sufficiently rigid but uneven or worn, Python LR can be used to smooth and level the timber substrate prior to over-boarding with plywood overlay or a tile backer board. If following this process, allow Python LR to cure before fitting the overlay boarding.

Mixing and Application

Always mix by adding powder to water. Python LR is mixed with a water content of 4.5 – 5.0 litres of water per 20kg of Python LR. In a clean mixing vessel, add the pre-measured water before adding the powder component slowly whilst mixing with an electric paddle until a smooth and lump free consistency is obtained. Once mixed, allow the product to stand for 2 minutes and stir again prior to application. Do not add further water once mixed. Exceeding 5.0 litres of water per 20kg will result in water bleed and therefore extended drying times and a weakened mix.

N.B. Once mixed, Python LR will remain workable in the bucket for 20 - 30 minutes at 20°C.

Pour a small quantity onto the prepared surface and trowel down lightly to a depth between 2mm and 50mm. The use of a spiked roller is recommended immediately in thin applications in order to remove entrapped air and smooth out flow lines. Setting time will depend on atmospheric conditions/temperatures, it will be slowed by lower temperatures and accelerated by higher temperatures. If a depth greater than 50mm is required, allow the first application to dry and prime the surface with Python PR at a 3:1 ratio before applying a subsequent coat. Clean tools immediately after use with clean water. Python LR is ideal for pump application. Mix in accordance with the pump manufacturer’s instructions and ensure that regular flow checks are carried out. Ensure the water content is correct and that there is no surface separation.

Setting and Covering

In ideal conditions, Python LR will accept light foot traffic after 3 hours. Python LR must be left to dry before applying the final decorative surface flooring. This is typically after 3 hours for ceramic tiles and 24 hours for decorative flooring such as vinyl, however, this can vary depending on the choice of surface flooring. Thicker applications may require a longer time to dry prior to applying floor coverings. If there is no air flow within site conditions, the drying time may be restricted. The critical moisture content for the flooring in question must be observed.

Suitable Substrates
  • Sand/Cement Screed
  • Concrete
  • Plywood Overlay (6mm min)
  • Electric Underfloor Heating
  • Water/Wet System Underfloor Heating
  • Tile Backer Boards
  • Existing Ceramic, Porcelain and Natural Stone Tiles*
  • Flooring Grade Asphalt & Bitumen*
  • Anhydrite Screeds
  • T & G Floorboards
  • Floating Floors
  • Existing Vinyl Tiles*
  • Steel/Metal Surfaces*
  • Epoxy DPM*
  • Existing Adhesive Residues
  • Fiberglass

* Prime with Python PR

Health and Safety

Python LR contains cement. Contact with moisture or gauging water sets off an alkaline reaction which may cause skin irritation and/or caustic burns to mucous membranes (e.g. eyes). Irritant to respiratory system. Risk of serious damage to eyes, therefore avoid contact with eyes and prolonged contact with skin. Do not breathe dust. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. After contact with skin, take off immediately all contaminated clothing, and wash immediately with plenty of water and soap. Wear suitable gloves (e.g. cotton gloves soaked in nitrile) and eye/face protection. If swallowed, seek medical advice immediately and show this container or label. Keep out of reach of children. Low in chromates.

For further information refer to the Material Safety Data Sheet.

The information contained on this spec sheet is given voluntarily and in good faith. It is to the best of our knowledge true and accurate; however it may contain information which is inappropriate under certain conditions of use. The company cannot accept responsibility for any loss or damage due to inappropriate use or the possibility of variations of working conditions and of workmanship outside our control.

Technical Data

Screed classificationCT-C16-F7 to EN13813:2002
Working time @ 20°C20 - 30 minutes
Time to foot traffic @ 20°C3 hours
Application thickness2mm – 50mm
Compressive strength N/mm2 (BS EN 13892-2)1 day > 15.0 7 day > 20.0 28 day > 30.0
Flexural strength N/mm2 (BS EN 13892-2)1 day > 3.0 7 day > 5.0 28 day > 7.0
Coverage20kg will cover 4.2m2 at 3mm thickness
Flow properties using 30mm x 50mm flow ring135 – 145 mm
Minimum application temperature5°C
Shelf lifeStored correctly this product has a shelf life of 6 months
Pack size20kg
NoteAll work must be carried out in accordance with British Standard Code of Practice.


Use the input fields provided below to calculate the amount of bags you would need.

Tiling Area

Thickness of Tile

Total Bags Needed

Product Documentation

Back to the Range