Cromar Hydrosil 18.9 Litre Professional Silicone Roof Coating AHYDSIL-601

Cromar Hydrosil Professional Grade 100% Silicone Roof Coating 18.9 Litre

10 Year Guarantee

Trade Size: 18.9 Litre

Colour: Grey

MPN: AHYDSIL-601

Barcode: 5036684022453

Product Overview:

Cromar Hydrosil is a professional grade, 100% silicone roof coating supplied in a trade-sized 18.9 litre drum. This solvent-based, moisture-cured liquid is designed for single-coat application, forming a seamless, waterproof and highly durable membrane over most common roof substrates and membranes.

Hydrosil bonds directly to suitable roofing surfaces without a primer in most cases, creating a vapour permeable, watertight barrier that resists UV, extreme temperatures, rain and standing water. The grey finish helps keep roof surfaces cooler in hot weather, reducing thermal shock and extending the life of the roof system on both commercial and domestic projects.

Key Features

• Professional grade 100% silicone roof coating for trade use

• Single-coat application forms a seamless, waterproof membrane

• Excellent direct bond adhesion to most common roof substrates

• Vapour permeable, watertight and weatherproof barrier

• Highly UV resistant, formulated to withstand extreme temperatures

• Grey finish helps lower roof surface temperatures and reduce thermal stress

• Self-levelling formula for an even, continuous coating

• Unaffected by standing water when fully cured

• No primer required on many suitable surfaces (check manufacturer guidance)

• Fast drying and curing times for quicker project completion

• Superior coverage – up to approx. 23m² per 18.9L drum (substrate dependent)

• 10-year product guarantee when applied in accordance with instructions

Specifications

• Brand: Cromar

• Product Name: Hydrosil Professional Grade 100% Silicone Roof Coating

• MPN: AHYDSIL-601

• Barcode: 5036684022453

• Trade Size: 18.9 Litre drum

• Colour (Dry Film): Grey

• Base: Solvent-based, moisture-cured silicone

• Application Method: Brush, roller or suitable spray equipment

• Coats Required: Typically single coat (check substrate and conditions)

• Coverage: Up to approx. 23m² per 18.9L (substrate and profile dependent)

• Drying Time: Typically 2–6 hours (depending on temperature and film thickness)

• Curing Time: Typically 4–8 hours to cure; full performance after full cure

• Foot Traffic: After approx. 24 hours (light foot traffic, as directed)

• Finish: Seamless, flexible, waterproof membrane

• Guarantee: 10 years when correctly applied to suitable substrates

Applications

• Refurbishment of existing flat and low-slope roofs

• Overcoating many aged roof membranes (subject to suitability and prep)

• Waterproofing concrete, masonry and suitable metal roof surfaces

• Protection of roof details, upstands, flashings and penetrations

• Use on commercial, industrial and residential roof projects

• Maintenance and restoration coating to extend roof service life

Application Kits Available: 9 inch Single Arm Application Kit or 12 inch Double Arm Application Kit

How to Use

• Ensure the roof surface is sound, clean, dry and free from dust, moss, loose material, oil, grease and contaminants before application.

• Carry out any necessary repairs to the substrate and check manufacturer guidance for any specific primers required on particular surfaces.

• Stir the Hydrosil thoroughly and pour into a suitable application tray or kettle if using brush or roller; set up spray equipment if spraying.

• Apply in a single, even coat by brush, solvent-resistant roller sleeve or suitable airless spray, avoiding puddling and ensuring a consistent film thickness.

• Allow the coating to dry as specified (typically 2–6 hours) and cure (typically 4–8 hours). Avoid traffic and standing water until the coating is fully cured.

• For application over large areas, consider using a 9" single arm or 12" double arm application kit to improve coverage speed and consistency.

Cromar Hydrosil Silicone Roof Coating – Key FAQs

• Is Cromar Hydrosil suitable for most roof types?
    Hydrosil is formulated for use over many common roof substrates and membranes. Always check compatibility and follow Cromar’s guidance for the specific roof type and condition.

• Do I need a primer before applying this coating?
    In many cases no primer is required, as Hydrosil has excellent direct bond adhesion. However, some substrates may need priming, so always refer to the manufacturer’s data sheets.

• Can this roof coating cope with standing water?
    Once fully cured, Cromar Hydrosil is designed to be unaffected by standing water, making it suitable for flat and low-slope roofs that may experience ponding.

• How much coverage can I expect from a 18.9L drum?
    As a guide, up to around 23m² per 18.9L can be achieved on smoother, less porous substrates. Rough or highly absorbent surfaces will reduce coverage.

• Why is the coating grey rather than black?
    The grey finish helps reflect more heat than a darker coating, which can reduce roof surface temperatures, minimise thermal shock and contribute to longer roof life.

• How long before the roof can be walked on?
    Light foot traffic is typically possible after around 24 hours, providing conditions have allowed the coating to cure properly. Always follow Cromar’s specific curing and safety recommendations.