Bitumen membrane and liquid-applied waterproofing are two of the most commonly specified systems in Botswana, and both do the same basic job — keeping water out. Contractors and homeowners often ask us which one to use, and the honest answer is: it depends on the roof or structure in front of you. Here's how the two compare, and how to think through the decision.
What Is Bitumen Membrane Waterproofing?
Bitumen membrane systems are sheet-applied — either self-adhesive or torch-applied. ABE's range includes abedex® HM, a high-movement, fibreglass-reinforced torch-on membrane designed for substrates prone to cracking or vibration; abe® peel & stick membrane, a self-adhesive option that needs no special equipment (just measure, cut, peel and stick); and malthoid 3 ply, an economical, self-healing membrane often used as a damp-proof course or roofing underlay. They're a proven, robust choice for flat and low-pitch roofs, podiums, and below-ground structures. Because the membrane is manufactured to a consistent thickness, you get a known, uniform waterproofing layer in a single application, with good puncture and abrasion resistance once it's down.
The trade-off is installation. Torch-on application requires a skilled, careful applicator — an open flame near a roof deck is not something to hand to an inexperienced crew — and the system works best on relatively simple, accessible roof geometry. Complex detailing around penetrations, upstands, and tight corners is harder to seal neatly with a sheet product than with a liquid one.
What Is Liquid-Applied Waterproofing?
Liquid-applied membranes — acrylic or rubberised bitumen — are brushed, rollered, or sprayed on to form a seamless coating that follows the exact shape of the substrate. ABE's super laycryl® is an all-in-one acrylic system used for flashings, valley gutters and ridging, and is specifically formulated for re-waterproofing over existing systems; super laykold® is a rubberised bitumen emulsion suitable even for potable water applications like koi ponds; and hydroproof® is a more economical acrylic option typically used with a reinforcing membrane for flashings and parapet walls. This makes liquid systems a strong choice for complex geometry: balconies, upstands, roofs with lots of penetrations, and remedial waterproofing over an existing surface where lifting old material isn't practical.
The trade-off here is that liquid systems typically need multiple coats to reach their designed thickness, and performance depends more on applicator technique and weather conditions during application — most liquid membranes need dry conditions to cure properly. Coverage rate and cure time are product-specific and should always be confirmed against the current data sheet before you plan a project timeline.
Bitumen Membrane vs Liquid-Applied: At a Glance
Bitumen Membrane — Best Suited To
Large, relatively simple flat or low-pitch roofs; podiums; below-ground structures; projects where a thick, uniform, proven sheet system is preferred over a build-up of coats.
Liquid-Applied — Best Suited To
Complex roof detailing, balconies and terraces, upstands and penetrations, and remedial overcoating of existing surfaces where a seamless, shape-following membrane is easier to achieve.
Which Should You Choose?
As a general rule: a large, simple, accessible roof or below-ground structure often favours bitumen membrane, since it's typically more cost-effective and gives a known, consistent thickness in one pass. Complex detailing, awkward shapes, or remedial work over an existing coating usually favours a liquid-applied system, since it can follow the geometry without needing sheet joints and detailing work at every corner.
But this is a general rule, not a rule of thumb to specify by. The right choice always depends on the substrate condition, structural movement, water exposure, and access — the same factors we cover in our complete waterproofing guide. If you're not sure which way to go, send us your project details and we'll recommend a system with the ABE technical documentation to back it.
Not Sure Which System Fits Your Project?
Tell us about your roof or structure and we'll recommend the right ABE waterproofing system, with documentation to back the specification.