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Wayne Bagnall Consulting - ‘Legacy Asbestos Spacer in concrete’

UKATA Member Wayne Bagnall Consulting spoke at the World Demolition Summit in Vienna, raising asbestos awareness and shared his case study on asbestos spacers.

This article has been provided by UKATA Member Wayne Bagnall Consulting


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The reason for presenting a paper on asbestos spacers in concrete is to raise awareness of the wide use of asbestos cement reinforced spacer blocks manufactured and installed in reinforced concrete structures from the 1960’s to the 1980’s used predominantly to ensure the steel reinforcing had sufficient coverage of concrete and used in reinforced concrete structures slabs, floors, soffits, columns, and beams.

Many of these older buildings are now being demolished or remodelled where these spacer blocks are likely to be disturbed and although they pose a very low risk to persons health, we must all be on the lookout for these asbestos spacers and undertake analysis to confirm if they contain typically chrysotile (white) asbestos or not.

Concrete containing these asbestos spacer blocks must be identified with additional measures employed over and above conventional damping down to minimise the risks from respirable crystalline silica (RCS).

World Demolition Summit 16 & 17 November 2022

The 14th World Demolition Summit organised by the KHL Group and Demolition & Recycling International (D&Ri) alongside the European Demolition Association (EDA) and the US National Demolition Association (NDA), the WDS combined a mix of conference, awards and networking and has run annually since 2009.

I attended and gave a paper at a very successful WDS 2022 an excellent venue at the Austria Trend Hotel Saveyon. The circa 300 delegates who travelled from around the world were treated to 10 interesting speakers managed by Thomas Kasper (am) and Stefani Panseri (pm) session chairpersons who fielded the questions and lively debates.

Asbestos Spacers in Concrete

My paper was the ‘implications of legacy asbestos spacer blocks in demolition’, this was well received and attracted lively debate with Q&A’s, my presentation covered;

  1. Introduction, Case Study & Asbestos Survey
  2. Asbestos cement products in concrete (history)
  3. Position of the UK Regulators
  4. Protocols, controls & limited re-use -vs- landfill
  5. Refurbishment & demolition implications when these asbestos spacers are present

Case Study & Asbestos Spacers

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It was in 2017 when I first came across these asbestos spacers on a large demolition project in central London where I was the clients Demolition Consulting Engineer for the demolition of a 7 storey, 1970’s reinforced concrete framed building, I recall advising on the pre-construction information requirements and in particular the arrangements for the ‘Asbestos (Demolition & Refurbishment) Survey. This survey was undertaken in 2 phases as this 1970’s building was initially still occupied, during the 2nd visit and after initial asbestos removal and soft-strip I noticed small (50mm) bow tie shaped impressions in the exposed floor soffits and asked the question what are these?

Having determined these were cement spacers blocks that had likely become loose had sank onto the formwork they were sampled and tested for asbestos as a precaution, to my horror they contained a significant circa 5% concentration of Chrysotile (white) asbestos!

Following additional sampling and testing it was determined these asbestos cement spacers were throughout the building, reference was made to the Control of Asbestos Regulations and REACH followed by intense dialogue with the regulators HSE, and EA.

Although the concentration of asbestos in the arisings was well below the hazardous waste threshold of 0.1% w/w we developed suitable protocols with control measures and implemented these to ensure the safe demolitions, processing and avoiding using limited and expensive landfill space. The arisings were placed into low-risk areas where it was unlikely to be disturbed in the future e.g. below car parks etc.

If you’d like a copy of my presentation, or have come across these asbestos spacers or you’d like a chat about this subject please send an email request to me at

Published on Thursday 24th November 2022

Posted in News Member News