Surface Preparation

Surface areas should be dry, clean and sound, free of voids, sharp protrusions or contaminants. The surface shall have a light steel trowelled or fine wood float finish.

Substrate and Falls

Roofing boards to be laid to faces 1:60 as per engineers specification. The moisture content is not to exceed 7% prior to torch-on application.

Special care must be given to all expansion/construction joints, refer to your a.b.e.® Technical Representative concerned for specific details.


New Concrete

Prime all surfaces with bitu.®prime, including all verges, and around outlets and protrusions and allow the solvent to flash off. Extremely porous surfaces should be reprimed.


Strip existing waterproofing before priming all surfaces with bitu.®prime, including all verges, around outlets and protrusions and allow the solvent to flash off. Some existing waterproofing materials may be overlaid only in consultation with the a.b.e.® Technical Representative concerned.



Apply a coat of bitu.®prime onto the plastered vertical substrate. Full bore outlet’s, pipe up stands to have a square meter of abe® unigum 4mm/Index Fidia P 4mm bonded to the surface including their gussets. All internal and external corners to have a gusset fitted, 100mm x 100mm, using abe® unigum/Index Fidia P 4mm prior to the commencement of the waterproofing application.

Apply 5 ply malthoid to the boarded roof sheets (boarded roof to falls) by mechanically fastening using 40mm diameter washers at 300mm centres.

Apply a single a single layer abe® unigum or abe® unigum MS 4,5 kg/sqm ensuring full bond to the 5 ply malthoid by means of ‘torch fusion’ using propane gas, having side and end laps of 100mm and 150mm respectively.

Apply abe® unigum 4mm or abe® unigum MS 4.5kgs/sqm counter flashing fully bonded to surface.

Apply super laycryl or super laykold and abe® membrane counter flashing onto the plastered vertical substrate.


Counter flashing surfaces are to be treated with 2 coats of super laycryl or super laykold incorporating abe® membrane, details as recommended in our data sheet. Ensure the lap over the torched membrane is at least 150mm.

Drainage Outlets

Specific attention must be given to the detail work when waterproofing the outlets to prevent ingress of moisture.


Index waterproofing membranes shall only be warranted when installed by a.b.e.® Construction Chemicals accredited contractors.

Care must always be taken when working with open flames, potential fire hazard, and molten bitumen from the process, employ safety equipment and clothing where necessary.

All products are to be applied in accordance with the manufactures instructions.

All relevant data sheets are to be carefully read for additional information.

Important Note

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® Construction Chemicals endeavours to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.® Construction Chemicals has no direct or continuous control over where and how a.b.e.® Construction Chemicals’ products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.® Construction Chemicals’ products, whether or not in accordance with any advice, specification, recommendation or information given by the company.

Further Information

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements. a.b.e.® Construction Chemicals has a wealth of technical and practical experience built up over years in the company’s pursuit of excellence in building and construction technology.

Typical Flat Boarded Roof Waterproofing Detail


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