ISOTHANE E.M.A. elastomeric membrane is a liquid applied coating based on urethane prepolymers that cure by reaction with atmospheric moisture to give a continuous film, which is rubbery and elastic. It contains leafing aluminium, which gives excellent U.V. resistance.
ISOTHANE E.M.A. is a very high solids coating designed to give a high-build film. It can be brush or spray applied (with airless spray equipment) but it has a higher viscosity than a conventional paint and should not be diluted.
ISOTHANE E.M.A. cures to a permanently flexible seamless membrane, which, by virtue of its chemical reactivity in the wet state, has good adhesion to a wide range of substrates (given proper preparation) such as rooting asphalt, states, tiles, asbestos, concrete, brick, wood, glass and metals. Unlike more traditional bitumen based products,
ISOTHANE E.M.A. does not readity embrittle with age, exposure to ultra violet radiation or weathering, and hence it does not crack or craze.Since it is elastomeric
ISOTHANE E.M.A. is not adversely affected by extremes of temperature consequently it does not crack at low temperatures or suffer thermal flow at elevated temperatures.
ISOTHANE E.M.A. can be applied by brush, airless spray or roller without the need to mix, stir or heat before application.

Areas of Application

ISOTHANE 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 sprayed polyurethane (p.u.) foam insulation. However, it is essential that 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
ISOTHANE products. Substrates with poor adhesion to the underlying structure (e.g. blistered roofing fett) may also cause problems in providing sound over-coating. Preferential vapour drive in buildings must also be borne in mind when overcoating the roof and it may be judged expedient to employ ventilation to cope with transmission of high levels of moisture vapour.

The dry film thickness (DFT) of ISOTHANE E.M.A. should not be less than 0.5 mm. or more than 1.0 mm for each coat. Rough or textured surfaces will reduce the coverage rate and consequently more material must be allowed to achieve the minimum D.F.T.
ISOTHANE E.M.A. is a membrane coating. not a paint and as such protection is only achieved with a high film build i.e. 1 mm. minimum. It is therefore essential that this is achieved. The membrane can be applied in one 1 mm. or two 0.5 mm. 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 recoat within 24 hours of the first coat becoming sufficiently cured to allow operator access. Do not dilute ISOTHANE E.M.A.


1. Remove all loose material by vigorous brushing, wire brush if necessary.
2. Treat any remaining fungal growth with proprietary fungicide as recommended.
3. Allow surface to dry thoroughly and any moisture contained in the structure to evaporate. ISOTHANE Special Primer and E.M.A. should not be applied to damp substrates.
4. Fill cracks and voids with a mastic sealant.
5. Prime with ISOTHANE Special Primer (6-10 m²/It) depending on substrate texture and porosity which cures to a slightly tacky film in 2-4 hours. Overcoat with ISOTHANE E.M.A. as soon as possible after this time and certainly within 48 hours. If delay exceeds this, repriming is advised
6. Apply ISOTHANE E.M.A. at a maximum film thickness of 0.5 mm. for two-coat applications and 1 mm. for one coat.
7. In the case of two coat application the first coat should be touch dry in 12-48 hours (in some conditions this might be delayed) and the second coat should be applied within 24 hours of this stage to ensure good adhesion.8. Second coat delay; If more than 24 hours elapse after the touch dry stage of the first coat, prime the entire surface with Special Primer and allow to dry before recoating within 4-8 hours.