Construction Fixings

By Barbara Sorgato,  secretary general, European Consortium of Anchor Producers

Whilst waiting for the publication of the final text of the revised Construction Products Regulation (CPR), company experts are testing the effects of the new law on their products based on the last available draft, approved by the European Council and parliament.

The first test is done in the framework of the ‘so called’ CPR Acquis, which consists of rewriting the legal basis (Standardisation Request) for future harmonised standards (hENs). Rewriting the legal bases means not only including everything that has been done so far in terms of harmonised standards, but also what one would like to harmonise in the future.

For fasteners, the test bed is that of timber connectors. The two main standards on timber connectors are the harmonised standards hEN 14592 and hEN 14545, both under revision. To bridge the gap between the blockage of the publication of standards under the current CPR – a blockage due largely to the lack of an appropriate legal basis – and the evolution of new connectors, in the last few years new European Technical Assessments (ETAs) have popped up on the market. Some of these ETAs overlap with revisions of existing standards, others cover new products. Experts are now trying to put things in order and have a solid legal basis for future harmonised technical specifications. They need to do it soon, because the next Standardisation Request in the pipeline of the CPR Acquis, whose work are expected to begin at the end of 2024, is on timber products and ancillaries.

Here we are talking about standardisation, i.e harmonised standards, and not ETAs. In the revised CPR, in fact, ETAs are defined as ‘outside of the harmonised zone’. Does the industry wish to have CE Marking inside the harmonised zone? Then it needs to make sure that issued ETAs are taken on board in the new legal basis of the CPR Acquis, so they can become standards in the near future. 

What ‘outside of the harmonised zone’ means is not explained in the revised CPR. The answer given to the questions posed by the experts of the European industry, anxious about the future of their investment in ETAs, is based on the opposite of the definition of the harmonised zone –
Member States cannot impose extra national regulations on products inside of the harmonised zone. On the contrary, in the case of technical specifications outside the harmonised area (i.e ETAs), Member States may require additional requests such as national certifications – for instance if they consider that an ETA does not meet the required characteristics/thresholds and levels for products placed in the market in those states. The sense of this is that, whilst European Assessment Documents allow for the assessment and sale of unique innovative products, these products might cause different requirements in different countries.

This does not mean that a CE Marking based on ETA is no longer valid, it is still valid but it just might not be enough – depending on each single Member State. What this does mean is that if a company wants to make sure their product circulates freely in the European zone, without any further additions and requests, they will have to go for a harmonised standard. 

Companies also need to be aware that some things have also changed at a design level. The design prescriptions given in ETAs are not taken on board automatically by the new generation of the Eurocodes. Some of them are, some of them are not. CEN and EOTA have also agreed that conflicting design rules are no longer allowed and will require action by EOTA. 

Bonded-in rods (BIR) are connectors used in timber, consisting of a bonding agent used in combination with a rod. Today, BIR are covered by an ETA and one of the two BIR components, the bonding agent, is covered by a non-harmonised test standard. The experts of the industry realised that, under the new CPR, this product will have no harmonised CE Marking, unless it is included now in the legal basis. So, they decided to give it a try and considered including BIR in it, in view of the starting works of the CPR Acquis for timber products and ancillaries. 

As convenor of CEN TC 124 WG4 ‘Timber connectors, I am part of the discussion within the CEN standardisation framework and would like to report here some bits of the debate.

By addressing the possible standardisation of BIR, critical issues have emerged that impact the entire world of fasteners. BIR is a connector and consists of a bonding agent and a rod/rebar. However, EADs covering bonded products call them BIR or injection anchors, whilst standardisation addresses only its component (adhesive, glue, bonding agent). Basically, when BIRs are used in free installation in job sites – and not coming out of the factory already glued in timber blocks – in the concrete world they are called ‘injection anchor’ or ‘bonded anchor’. Instead, as the worlds of wood and concrete live on different planets and use different terms, in the wood world BIR are called ‘bonded-in rods (former glued-in rods)’ and their bonding agent is called ‘glue’ or ‘adhesive’. 

It is not only about terminology, the test standard on the bonding agent for BIR was drafted by a technical committee dealing with adhesives. In the concrete world, adhesives are addressed for repair purposes only and focus rather on the adhesive properties, whilst injection anchors are covered by ETAs deriving from a previous ETAG, developed by experts addressing the product ‘fastener’ – focusing on the structural behaviour of the system ‘bonding agent plus a certain rod and a certain concrete’. 

It seems to me that with the use of mixed wood-concrete structures increasing, due to them being a very good solution in terms of sustainable construction, connectors are going to be used more and more in free installation and coexisting in mixed structures with other post-installed fasteners. That is why the CE Marking approach of fasteners used in wood, in concrete, in masonry, stones, and other base materials, should aim at a common approach and terminology. 

During the CPR Acquis work, Member States expressed the wish to handle fasteners in a separate group, which is in the pipeline for standardisation. We do not know if this group will put together timber and concrete, but it seems to me that a first step in this direction has already been done. Finally, it seems to me that, because post-installed fasteners are due to be standardised in the coming years, the industry is taking the chance to test the challenges and the practical implications of the standardisation of a bonded fastener, to be prepared for a possible future transition from ETA to hENs.