Beam & Block Waterproofing

Beam & Block Floor Waterproofing

Beam & block flooring consist of modular concrete units with natural joints, gaps and (as a result) uneven surfaces. The PolyMaxx HA waterproofing system is perfect for applying to all types of deck substrates, however beam & block floors require a stabilising ‘carrier’ layer before waterproofing can begin. This ensures a smooth, continuous surface and prevents water tracking across irregularities.

Characteristics of Beam & Block Floors

Beam and block flooring is a versatile, suspended concrete flooring system, often used in residential and commercial construction. This is thanks to its ability to quickly create a durable, rot-proof, and fire-resistant floor.

Its speed of installation means it is widely used in new-build homes, extensions, and renovations, where the high load-bearing capacity is also a benefit.

• Use PolyMaxx Carrier SF self-adhesive sand-faced bituminous membrane above the deck. The carrier membrane creates a smooth, stable surface across irregular modular slabs such as block & beam
• The PolyMaxx Carrier SF membrane is easily installed with PolyMaxx Carrier Adhesive – no additional primer required
• Once installed, the PolyMaxx Carrier SF also does not require priming before the PolyMaxx HA resin is installed
• Use PolyMaxx HA Primer on any masonry elements such as upstands, prior to the installation of the PolyMaxx HA resin
• PolyMaxx Detailing Primer should also be used for any metal interfaces, details, trims and penetrations

Considerations for Waterproofing Beam & Block

Install a Carrier Layer

Beam & block floors require a carrier membrane layer to create a smooth and stable surface across the irregular surface that is naturally created by modular concrete units:

• Use PolyMaxx Carrier SF, a self-adhesive and sand-faced bituminous membrane above the beam & block floor
• This is easily installed with PolyMaxx Carrier Adhesive – no primer required

Waterproofing Over the Carrier Layer

Once a carrier layer has been installed to provide a clean, flat and consistent surface for the waterproofing membrane:

• Masonry upstands should be primed using a waterproofing primer, PolyMaxx HA Primer
• Metal interfaces should be primed using a specialist primer for metal, such as PolyMaxx Detailing Primer
• However, no primer is required over the PolyMaxx Carrier SF membrane itself, which is ready  for the PolyMaxx HA resin to be applied directly to the sand-faced surface

Why PolyMaxx Works on Beam & Block Construction

• The reinforced carrier layer accommodates minor deck movement
• PolyMaxx is a fully bonded waterproofing system that eliminates lateral water tracking
• Rapid curing system (30-60 minutes), enables quick installation and efficient project sequencing
• Suitable for block & beam substrates used in any scenario, from large-scale new-build housing developments to public and commercial sector projects and existing structural extensions or renovations

Our system ensures a durable, long-term waterproofing solution for all beam & block projects.

Installer Requirements

To qualify for the 20-year PolyMaxx warranty, your beam & block waterproofing installation must be carried out by Newton PolyMaxx-certified contractors and accompanied by full photographic and environmental documentation.

Contact Newton Waterproofing

Need project‑specific guidance? Our technical team can advise on:

• Whether Carrier SF is required based on your build-up
• Correct preparation for beam & block substrates
• Upstand and metal interface priming
• Suitable anti‑slip or protective finishes
• Integration with your overall waterproofing and structural design

For technical guidance, NBS specifications, or help selecting the correct system for block and beam waterproofing, contact Newton’s technical team.