Surface Preparation

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

Substrates and Falls

Screeds are to be sand cement laid to minimum falls of 1 in 60, the strength and thickness as per engineers specification. The moisture content is not to exceed 7% prior to torchon applications.

Should light weight screeds be employed an additional sand cement screed is to be placed on top of the light weight screed, the strength and thickness as per engineers specification. Under no circumstances must the torchon material be applied directly onto the light weight screeds.

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


New Roof

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 re-primed.


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


abe® unigum 4 mm, South African Agrement Certified (Certificate No. 97/261).

Full bore outlets, pipe upstands to have a square metre of abe® unigum 4 mm bonded to the suface including their gussets. All internal and external corners to have a gusset fitted, 100 mm x 100 mm, using abe® unigum 4 mm prior to the commencement of the waterproofing application.

Apply a single layer abe® unigum or unigum 4 mm or MS 4.5 kg, non-woven polyester reinforced, ensuring the layers are fully bonded to the bitu.®prime primed surface by means of torch-on fusion, using propane gas, having side and end laps of 100 mm and 150 mm respectively.

The rolls are to run parallel to each other, centrally staggered to prevent joints overlapping.

See data sheet ‘Six Golden Rules’.


Counter flashing over the balance of the parapet is recommended using 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.

Protection Layers

All plain exposed surfaces are to treated with 2 coats of silvakote as protection layer against UV rays. The coating should be applied 6 to 8 weeks after torching process to allow the surface to oxidise slightly thus providing good adhesion of the coating.

Should loose stone ballast be the finished surface, then apply the plain surface of index torchon membrane opposed to “MS” as the final layer followed by a single layer of malthoid 5 Ply as a protection layer having side and end laps of 150 mm respectively, laps bonded using bitu.®grip. The stone ballast to be laid on top of the malthoid 5 Ply.

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 installed by contractors accredited by a.b.e.® Construction Chemicals Limited.

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 the products are to be applied in accordance with the manufacturers 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.






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