Python HF


A rapid setting, high performance latex based two part smoothing compound consisting of a specially formulated powder component that is mixed with a pre-gauged, protein free and high polymer content liquid.

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Product Details

Install decorative floor coverings after 4 hours and ceramic tiles after 3 hours

Suitable for use over old adhesive residues including bitumen

Moisture tolerant - can be used below a DPM

Excellent flow and self-levelling properties

Ideal for use above underfloor heating systems

Ideal for timber substrates

Apply directly to a dpm within 24 hours without priming

Low odour

Walk on on 90 minutes

Protein free

2 - 12mm bed thickness

Technical Specification


Python HF is a rapid setting, high performance latex based two-part self-levelling floor compound. The specially formulated powder component is mixed with a pre-gauged, protein free polymer latex liquid, giving a free-flowing, shrinkage compensated self-levelling floor compound.

Python HF has excellent flow and adhesion properties making it suitable for a wide range of both commercial and domestic applications. These unique properties ensure that Python HF can be used with confidence without the need to prime the large majority of substrates. Python HF is suitable for use over a wide range of substrates including sand/cement screeds, concrete, flooring grade asphalt/bitumen, ceramic, porcelain and terrazzo tiles, rigid steel, moisture tolerant old adhesive residues, epoxy damp proof membranes and plywood.

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

Once mixed, Python HF will remain workable for 20 - 25 minutes and it will accept light foot traffic after 90 minutes in ideal conditions. Decorative floor coverings can be installed after 4 hours and ceramic tiles can be applied after 3 hours. Python HF can be applied from depths of 2mm – 12mm in one application.

Python HF is moisture tolerant and it can be used to smooth subfloors prior to the installation of a DPM.


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.

When installing moisture sensitive floor coverings, the concrete or sand/cement screed should be confirmed dry by consistent moisture readings; <75% relative humidity (RH) or <0.5% residual moisture when tested in accordance with BS 8203. 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 as a fast one coat DPM must be applied before or after the application of Python HF. Surface laitance should be removed from concrete and sand/cement screed surfaces prior to application.

Most substrates do not require priming prior to the application of Python HF. Priming the substrate however 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 whilst not necessary, it 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 HF 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 HF to cure before fitting the overlay boarding.

Mixing and Application

Shake the pre-gauged bottle of liquid polymer and pour into a suitable clean mixing vessel. Add the powder component slowly whilst mixing with an electric paddle and continue to mix for a further 2 minutes until a smooth and lump free consistency is obtained, allow the product to stand for a further 2 minutes prior to application.

Once mixed do not add further polymer liquid or water.

N.B. Once mixed, Python HF will remain workable in the bucket for 20 - 25 minutes at 20°C.

Pour a small quantity onto the prepared surface and trowel down lightly to a depth between 2mm and 12mm. The use of a spiked roller is recommended immediately 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 the substrate is impervious or if it contains old adhesive residues, Python HF should be applied to a minimum overall thickness of 3mm. This is to ensure the uniform drying of the adhesives that are subsequently applied to the Python HF, it will also ensure that there is no interaction between the new adhesive and old adhesive residues.

Setting and Covering

In ideal conditions, Python HF will accept light foot traffic after 90 minutes. Python HF must be left to dry before applying the final decorative surface flooring. This is typically after 4 hours for decorative flooring such as vinyl and 3 hours for ceramic tiles, 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
  • Plasterboard
  • Existing Vinyl Tiles
  • Steel/Metal Surfaces*
  • Epoxy DPM**
  • Existing Adhesive Residues
  • Green Screed
  • Cement/Sand Render
  • Concrete Brick/Block
  • Fibreglass

* Prime with PR

** If DPM is more than 24 hours prime with PR

Health and Safety

Python HF 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 - 25 minutes
Time to foot traffic @ 20°C90 minutes
Application thickness2 - 12 mm
Compressive strength N/mm2 (BS EN 13892-2)1 day > 9.0 7 day > 12.0 28 day > 16.0
Flexural strength 4.0 N/mm2 (BS EN 13892-2)1 day > 3.0 7 day > 4.0 28 day > 7.0
CoverageA 20kg bag and 5.0Ltr liquid unit will cover 5.0m2 at 3mm thickness
Flow properties using 30mm x 50mm flow ring135 – 150 mm
Minimum application temperature5°C
Shelf lifeStored correctly this product has a shelf life of 6 months
ColourPowder - Grey Liquid - White
Pack sizeBag 20kg Liquid 5 Litres
NoteAll work must be carried out in accordance with British Standard Code of Practice.


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