ALLCOAT Polyflex EM Roof Membrane

Grey finish for wood or metal. Also for ashphalt/bitumen roofs.

Polyflex EM Roof Membrane


20Ltr – £135.00

ALLCOAT Polyflex EM Roof Membrane is a liquid applied coating based on polyurethane prepolymers, which cures by reaction with atmospheric moisture to give a continuous film that is rubbery and elastic. It contains leafing aluminium, which gives excellent UV resistance. A coating of 1mm dry film thickness will give a durable life of 10 years.

ALLCOAT Polyflex EM Roof Membrane is a very high solid coating designed to give a high build film. It can be brush or roller applied but it has a higher viscosity than a conventional paint and should not be diluted.

ALLCOAT Polyflex EM Roof Membrane cures to a permanently flexible seamless membrane that, by virtue of its chemical reactivity in the wet state, has good adhesion to a wide range of substrates. Unlike more traditional bitumen based products, ALLCOAT Polyflex EM Roof Membrane does not readily embrittle with age, exposure to ultra violet radiation or weathering, and hence it does not crack or craze.

Since it is elastomeric, ALLCOAT Polyflex EM Roof Membrane is not adversely affected by extremes of temperature – consequently it does not crack at low temperatures or suffer thermal flow at elevated temperatures.

ALLCOAT Polyflex EM Roof Membrane can also be supplied as a sprayable (with airless spray equipment) grade. Please refer to Instructions on the correct procedure.

Areas of Application:

The elastomeric membranes are designed to bond to many types of substrate particularly those commonly used as roofing, such as felt, asphalt, slate, tiles, asbestos, concrete, brick, wood, glass and metals. They can also be applied to spray polyurethane (PU) foam insulation. However, it is essential that the substrate and structures are properly prepared and stable.

Surfaces previously treated with silicone based materials will inevitably be difficult to overcoat and this should not be attempted with ALLCOAT products. Substrates with poor adhesion to the underlying structure (e.g. blistered roofing felt) may also cause problems in providing sound over coating.

Preferential vapour drive in buildings must also be borne in mind when overcoating a roof and it may be judged expedient to employ ventilation to cope with transmission of high levels of moisture vapour.

Methods of Application:

The dry film thickness (DFT) of ALLCOAT Polyflex EM Roof Membrane should not be less than 0.5mm or more than 1.0mm for each coat. Rough or textured surfaces will reduce the coverage rate and consequently more material must be allowed to achieve the minimum DFT.

ALLCOAT Polyflex EM Roof Membrane is a membrane coating, not a paint and as such protection is only achieved with a high film build, i.e. 1mm on flat surfaces minimum. It is therefore essential that this is achieved. The membrane can be applied in one 1mm or two 0.5mm coats. Two coats are recommended on uneven and jointed surfaces to minimise the possibility of thin patches, missed areas and pinholing. In the case of two-coat application, it is important to re-coat within 24 hours of the first coat becoming sufficiently cured to allow operator access.

Coverage rates may vary with surface texture and porosity. The information given is based on average usage. A site trial is recommended.

ALLCOAT PU Primer: 6 – 10m²/lt

ALLCOAT Polyflex EM Roof Membrane: 1 litre/m² on a smooth flat surface will provide an adequate film thickness of approximlately 1mm.

Any surface texture will increase the surface area which must be allowed for when calculating usage e.g. on a chipping embedded surface the actual area will be approximately doubled.

Sloping / vertical surfaces: Total coverage 0.7 lt / m² in 2 coats to give DFT approximately 600 microns.


Do not dilute ALLCOAT Polyflex EM Roof Membrane

1. Remove all loose material by vigorous brushing, wire brush if necessary.
2. Treat any fungal growth with fungicide as recommended.
3. Allow surface to dry thoroughly and any moisture contained in the structure to evaporate. ALLCOAT PU Primer and ALLCOAT Polyflex EM Roof Membrane should not be applied to damp substrates.
4. Fill cracks and voids with ALLCOAT polyurethane mastic sealant.
5. Primer with ALLCOAT PU Primer (6-10m² / depending on substrate texture and porosity) which cures to a slightly tacky film within 2 – 4 hours. Overcoat with ALLCOAT Polyflex EM Roof Membrane as soon as possible after this time and certainly within 48 hours. If delay exceeds this, re-priming is advised.
6. Apply ALLCOAT Polyflex EM Roof Membrane at a maximum film thickness of 0.5mm for two coat applications and 1mm for one coat.
7. In the case of two coat application, the first coat should be touch dry 12 – 48 hours (in some conditions this might be delayed).
8. Day work joints where application extends over more than a working day, an overlap of 150mm should be used.
9. Aromatic hydrocarbon solvent should be used to clean equipment etc.

ALLCOAT Polyflex EM Roof Membrane Spray Grade: Application

Only airless spray should be used 63 : 1 Graco King
Compressor: 100psi, 60cfm minimum
Tip Size: 21 – 25 thou 50° angle
100’ x 3/8 House and 25’ Whip End

Spray Application Rate:

ALLCOAT Polyflex EM Roof Membrane is easily and quickly applied manually at a rate of 40m² per man or up to 600m² per day by spray application.



20 litres


Dark Grey

ALLCOAT Polyflex EM Roof Membrane TDS   ALLCOAT Polyflex EM Roof Membrane TDS

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