ZeroPlus mortar being applied to Porotherm block.

Cavity clay block system

Build quicker, build smarter

A modern construction method with the reassuringly traditional values of clay, the cavity system gives you the ability to construct a water-tight structure by taking the external leaf off the critical path, when designed appropriately.

A multi-cellular clay block walling system designed with efficiency and performance in mind, the system has been expertly designed as a solution for any number of common construction requirements.

Discover the Cavity clay block range

Find out how Porotherm can help you build quicker, smarter and better

A modern construction method with the reassuringly traditional values of clay, the Porotherm Cavity System covers all your requirements for load bearing and non-loadbearing inner and outer leaves.
Download the brochure now to find out more.

Quality & Performance

Discover the benefits of using a cavity clay block walling system

  • The multi-cellular clay blocks are suitable for exterior and interior walls in cavity construction.
  • The cavity block gets their properties from air pockets being created during the clay firing.
  • Capable of achieving storey height (3m) within a day.
  • Weathertight construction allows for parallel internal and external work.
  • Lighter, safer, and easier to lay.
  • Less waste and less stock on site.
  • Interlocking construction with no mortar on vertical joints.
  • Uses less water than traditional methods.
  • Class A1 fire rated.
  • Suitable for multiple wall types.

Cavity clay block accessories

Multi-cellular clay block tools and components are specifically engineered to make laying as efficient as possible. You can also find wall ties, cavity trays and lintels through our approved distribution network. Please refer to best practice guide for more information or speak to our Technical or Sales team to find out more.

Cavity rollers

Our gravity fed rollers are specifically designed for use with Porotherm blocks and come in two sizes to cover the three block types.

Zero Plus Mortar

We cannot always rely on the weather here in the UK, so a mortar that can be applied from 0 degrees and rising helps to avoid delays on site.


Engineered to increase air tightness and to optimise the sound and thermal performance of Porotherm clay blocks, for use prior to dry lining.

Man wearing hard hat looking at Porotherm clay block wall

Contact us

Do you have a question, or want to know more about how we can help you on your next project? Get in touch today.


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