Waterproofing exposed flat concrete roofs the a.b.e. way

Typical screeded roofs require a single layer of waterproofing detail but can be specified as a double layer of waterproofing detail when required.

By Leading Architecture + Design and a.b.e.

Surface preparation

Surface areas should be dry, clean and sound, and free of voids, sharp protrusions or contaminants. The surfaces should have a wooden-trowelled finish laid at a minimum fall of 1:60 to outlets.

Priming

New areas: Prime all surfaces with bituprime, including all verges, around outlets and protrusions, and allow the solvent to flash off. Extremely porous surfaces should be re-primed.

Rejuvenation: Strip existing waterproofing before priming all surfaces with bituprime, 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.

Waterproofing system

Single layer: bituprime, abedex unigum 4mm, abedex V-SR 4mm or abe torch-on 4mm, as well as silvakote UV protective coating.

Double layer:  abedex® double layer waterproofing of exposed flat concrete roofs includes bituprime for priming of the substrate, abedex® unigum 4mm and 3mm torch-applied membranes, as well as silvakote UV protective coating. These systems need to be installed by experienced and approved applicators.

Apply the layer of abedex dual-reinforced waterproofing membrane, ensuring it is fully bonded by means of ‘torch-on fusion’ using propane gas, having side and end laps of 100mm and 150mm respectively. A minimum of 150mm should protrude above finished ground level. The rolls are to run parallel to each other, centrally staggered to prevent joints overlapping.

Flashing system

Counterflashing over the balance of the parapet is recommended using super laycryl or super laykold incorporating abe® membrane, details as recommended on datasheet. Ensure the lap over the torched membrane is at least 150mm.

Protection layers

All plain exposed bitumen surfaces are to be treated with two coats of silvakote as a protective layer against UV rays. The coating should be applied six to eight weeks after the torching process to allow the surface to oxidise slightly, thus providing good adhesion of the coating.

General

abedex torch-applied waterproofing membranes should only be installed by contractors accredited by a.b.e.® Care must always be taken when working with open flames, potential fire hazards and molten bitumen from the process. Employ safety equipment and clothing where necessary. All the products are to be applied in accordance with the manufacturer’s instructions. All relevant data sheets are to be carefully read for additional information.

www.abe.co.za

You may also be interested in:

  • super laykold 
  • abedex unigum 4mm mineral slate (MS) 
  • abedex V-SR 4mm mineral slate (MS)
  • abeproof PU ECO
  • abeproof liquid membrane
TopBuilt with Shorthand