Ideal for below ground applications, Fosroc ANZ’s Proofex 3100 is a high performance, bituminous self-adhesive sheet waterproofing membrane. A versatile product offering a simple application process, it’s no wonder Proofex 3100 is popular with builders, applicators and asset owners all around the country. 


When combined with Fosroc Primer 24 and Proofex Sheetdrain 81, Proofex 3100 provides a superior waterproofing system for diverse, below ground applications.

Where is Proofex 3100 used?

Proofex 3100 delivers excellent below ground waterproofing. It is ideal for:

  • basements
  • retaining walls
  • lift pits
  • underground garages and carparks
  • tunnels
  • box culverts and planter boxes

Used to protect homes and commercial assets from water penetration, Fosroc ANZ Account Manager Geoff Owen says Proofex 3100 ensures structural durability, longevity and sustainability.


“Proofex 3100 is typically applied in areas that are incredibly difficult – if not impossible – to access at later stages of construction, which makes product selection and application absolutely critical,” Geoff explains.

Why choose Proofex 3100?

Sheet membranes offer multiple advantages. Unlike liquid-applied waterproofing membranes, sheet membranes are easier to apply and offer even thickness and consistency. Proofex 3100 is a best-in-class product that delivers:

  • Self-adhesive strength: offering excellent adhesion, Proofex 3100 is incredibly sticky and bonds extremely well to the substrate
  • Diverse substrate application: Proofex 3100 bonds tightly to concrete, besser block, and bitumen
  • Fast application: With no dry time required, Proofex 3100 can be applied quickly, allowing project timelines to be met
  • Uniform thickness: Unlike liquid waterproofing membranes, Proofex 3100 offers uniform thickness without the need for film gauges or levelling
  • Fully bonded overlaps: Proofex sticks extremely well when achieving detailing around corners and edges
  • Ease of application: Proofex 3100 is easy to apply. No torches, heat or specialist equipment (such as film gauges or pressure gear) is needed
  • Safer application: With no need for torches or heavy equipment, any risk to applicators and others on site is minimal

Proofex 3100 application tips

To achieve the best results with Proofex 3100:

  • Prime concrete and besser block surfaces with Fosroc Primer 24 on the same day 
  • Ensure Proofex 3100 is terminated properly at the top and bottom, and that it’s adhered completely to itself
  • Ensure corners are executed with complete overlaps

A complete waterproofing system: Fosroc Primer 24 + Proofex 3100 + Proofex Sheetdrain 81

In areas where backfilling occurs, waterproofing sheet membranes are often used in conjunction with drainage membranes. 
Fosroc ANZ offers a complete, proven membrane waterproofing system comprising:

  1. Primer: Primer 24 
  2. Sheet waterproofing membrane: Proofex 3100
  3. Drainage membrane: Proofex Sheetdrain 81

Proofex Sheetdrain 81 ensures excellent drainage and provides robust protection from damage from backfill materials.


“A key advantage of Proofex Sheetdrain 81 is that it features a layer of polypropylene geo-textile fabric. Many drainage shells are just the dimples, and you need to add a separate geo-textile fabric product over the top, adding time and fuss to the job,” Geoff says.

The Proofex 3100 self-adhesive waterproofing system in action

Canberra lift shaft
Fosroc Primer 24 + Proofex 3100 + Proofex Sheetdrain 81 were applied to waterproof this concrete lift shaft in a retirement village in Downer, in Canberra’s inner north. 
“Waterproofing took place before the basement slab was poured,” explains Geoff. “Fast turnaround was required to keep the project on track. Once the basement slab was poured, there would be no access to the lift shaft, so the waterproofing had to be 100%.”

Basement garage in high end home

At this high-end build in Canberra’s Red Hill, Fosroc Primer 24 + Proofex 3100 + Proofex Sheetdrain 81 were applied to waterproof a 10-car basement garage. 
“Proofex 3100 is ideal for a besser block structure like this. Because it’s so porous, besser block absorbs liquid waterproofing membranes, but a quality sheet membrane like Proofex 3100 adheres to it beautifully. Backfilling took place shortly after application.”

A quality system backed by fast product supply and excellent support

Geoff says asset owners and applicators alike love the Fosroc Primer 24 + Proofex 3100 + Proofex Sheetdrain 81 system.


“Applicators love the system because it’s easy to use and does the job right the first time. In areas that are backfilled and can’t be accessed in future, there is literally no margin for error – you have to get the waterproofing right from the get-go.


“Being able to purchase all required products directly from Fosroc is another plus. It’s very convenient to place and receive everything in a single order. And because they are manufactured locally, Fosroc Primer 24, Proofex 3100 and Proofex Sheetdrain 81 are readily available so there are no hold ups.”
Fosroc ANZ product specialists like Geoff provide applicator support including via phone, email, text and on-site visits.


“Fosroc customers can contact us for on-the-spot help, advice and troubleshooting. We know how critical waterproofing is. Applicators using Fosroc’s products and systems can feel confident knowing they are working with quality products, backed by expert support.”

Find out more by visiting the respective product pages, linked below.