Application guide

Applying Overcoat to GRP Fibreglass

How to apply the Overcoat roofing system to a GRP fibreglass roof Any dirt, soil or other contaminants must be removed from the roof's surface before installing the Overcoat system.

Construction·Overcoat·Updated June 2022

Applying Overcoat to GRP

How to apply the Overcoat roofing system to a GRP fibreglass roof

Surface preparation

Any dirt, soil or other contaminants must be removed from the roof's surface before installing the Overcoat system. Remove any existing GRP roofing topcoat that appears to be flaking or loose. After the initial cleaning, the surface should be power washed and rinsed to remove all residual dirt and contaminants after which the surface should be dried.

Fill any cracks with Sharkseal multi-surface sealing adhesive and allow to cure following the product application guide.

Applying the Overcoat

Once the surface preparation has been completed you apply the Overcoat system with a standard roller or brush at a rate of approximately 1.2 kg per square metre. The Overcoat layer will become instantly watertight and can immediately withstand rainfall. After 24 hours the surface can take foot traffic and a full cure of the system will take around 7 days.

If a second coat is required then this needs to be applied at least 24 hours after the first layer. Application is the same as the first layer by roller or brush at a coverage rate of 1.2 kg / per m sq, to the full roof area.

Curing times

Please refer to the Overcoat product spec for a breakdown of the curing times. Depending on weather conditions, a full cure will take a minimum of 7 days but the roof can withstand foot traffic 24 hours after, depending on weather temperatures.

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