SIG Hydrostop AH15+

Manufacturer: AccuRoof 

Materials: Polyurethane 

The Hydrostop AH15+ Roof Waterproofing System is a modified polyurethane liquid-applied roof waterproofing system comprising:
• Hydrostop AH15+ Waterproof Coating — a single-part, moisture-triggered polyurethane waterproofing coating
• Hydrostop AH15+ Reinforcing Fabric — a fine polyester mesh for system reinforcement, 110 g·m-2 mass per unit area
• Hydrostop AH+ Blocker Primer — for the preparation of bitumen membranes and asphalt prior to the application of the system
• Hydrostop AH+ WP Primer — for the preparation of timber substrates prior to the application of the system
• SIG Approved Carrier Membrane— a heat-activated, polyester-reinforced, SBS modified bitumen membrane for use as a carrier membrane over insulation boards
• Hydrostop AH+ Standard Quartz Sand — anti-skid additive with a granule size of 0.4 to 0.8 mm for use in areas of pedestrian traffic
• Hydrostop Transparent — used to seal the applied Hydrostop AH+ Standard Quartz Sand.

The coating has the following nominal characteristics:
Specific gravity (g·cm-3) 1.44
Colour mid grey.

BBA logo

Number: 19/5705 PS2 Issue 2
Issue date: 27/02/2024

Approved for use on

Flat Roofs Pitched Roofs 

For use as a roof waterproofing system on new and existing flat and pitched roofs with limited pedestrian access.

The system, when used in combination with Hydrostop AH+ Standard Quartz Sand, is also satisfactory for use on flat roofs pedestrian access.


Concrete Insulation Boards Mastic Asphalt Metal Reinforced Bituminous Membranes Timber 

The system is for use on the following substrates:
• concrete
• mastic asphalt
• metal
• reinforced bitumen membranes (including mineral surfaced)
• wood
• SIG-approved glass faced Insulation boards
• SIG-approved insulation boards in conjunction with an approved carrier membrane.


10 Years 

The system will achieve a life expectancy of at least 10 years.

Installation Requirements

The system should only be installed by contractors who have been trained and approved by the Certificate holder.

Fire Safety

In the opinion of the BBA, a system comprising an 18 mm plywood substrate primed with bitumen based SA Primer, bituminous self-adhesive VCL, a polyurethane adhesive, 120 mm thick polyisocyanurate insulation board, bituminous self-adhesive underlay primed with Hydrostop AH+ Primer, and the Hydrostop AH15+ Roof Waterproofing System reinforced with a 165 g·m–2 polyester fleece can be classified as BROOF(t4) in accordance with BS EN 13501-5 : 2016.

Certified Products

The following products are also covered by the same certification:

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Unit 31F, Gelders Hall Road
LE12 9NH

T : 01509 505714

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