Like many other products, there has recently been a change in demand for certain applications and installation procedures. this has resulted in a change of the selection in anchor type but both architect and installers. The shift has tended towards the more traditional mechanical anchor, like through bolts, for simple push through and expansion type fixing. More recently the tendency to use a concrete screw has vastly over shone the initial fears that our marketplace had of hydrogen embrittlement and the removal of the washer heads under failure.
However, there has recently been a resurgence in chemical anchors. There seems to be more and more problem substrates that cannot take a mechanical anchor occurring in day to day construction. Whether this is due to a lot of residential refurbs that come from private households or if this is due to a large a government led re-clad scheme that has been running for many years and is attempting to convert some of the UK 1960’s eyesores into a much more attractive place to live.
A lot of the buildings lined up for the government re-clad are often unknown substrates, i.e density or old age. This is a perfect type of application where a resin anchor would be a much more viable solution. If you don’t know the substrate type, use chemical anchors. If you don’t know the age of the concrete or base material, use chemical anchors.
Most of the building work for re-clads or any refurb on older buildings aged around 50+ years old, are more suitable for chemical anchors. Construction has come a long way since the 1960s and a lot of old practices and materials have now either gone out of fashioned or been shunned by the industry. For this reason, we see the drive more and more towards finding a solution to alleviate pressure on facing brick or existing fixings in situ or where expansion anchors have been tried and failed
Over the last several years fischer have been scaling up their performance resin anchors. Previously the top end products from Fischer were the FIS V (Vinyl-ester hybrid), FIS EM (Epoxy mortar) and the FIS P polyester resin.
All these products have had a serious revamp with fischer focusing on new attributes to each product and pushing the boundaries of product service life. Of course, each variation has its own improvements and attributes but generally fischer have made the safest and easiest to use resin anchors on the marketplace.
First up was the FIS EM Plus. The epoxy mortar for heavy duty use and anchoring super structures made from various material, bridges, crash barriers and for post-installed rebar. The EM Plus was the first epoxy mortar in the world to have an approved service life of 120 years! Within the new ETA there has been several other areas of improvements, increase of characteristic loads in both cracked & non-cracked concrete as a leading example, along with reduced drill diameters required for certain diameters that will in turn drastically reduce installation time and reduces the possibility of installer errors. Finally, the optimisation of edge distances and spacing allows the EM Plus to be much more flexible at the design phase.
Next in line for a “plus” was Fischer's polyester offering, The FIS P + Polyester has always been the go to choice for many installers and trades but it can also be a very dangerous product for “general use” if the application is wrong. Normal polyester resin cannot be used outside or in damp conditions as shrinkage can occur which would result in the resin not fully filling the hole you drilled. Also any damp environment can cause other polyesters not to set at all and/or not to bind to the substrate.
The New FIS P Plus however offers features that you would not normally expect within its product group. The FIS P Plus can be used externally and in water filled holes and this is ETA approved. Meaning if you are aiming for the low end of the resin spectrum you can still be safe in the knowledge that the product you are buying is fit for purpose and has been rigorously tested in the applications environment.
FIS V PLUS
The headline product from the latest range of chemical fixings is the FIS V Plus. This chemical anchor system is the most useful in terms of application spread. There are many different vinyl-ester resins available across the UK. Some are tailored to specific applications and performance requirements but what makes the FIS V Plus truly unique is its range of ETA approvals in multiple substrates including masonry, concrete and post installed rebar connections. The choice of applications is limitless with this product which is why it is seen as one of fischers best selling products made to the highest specifications.
The styrene-free vinyl ester hybrid mortar with its numerous fixing elements is approved for fixing in cracked and non-cracked concrete as well as in masonry and the fischer remedial wall tie VBS 8, the fischer weather facing wall tie FWS II, and the stand-off installation system TherMax.
The variant FIS VS Plus Low Speed enables an extended curing time at higher processing temperatures or a greater drill hole depth. The shorter hardening time of the variant FIS VW Plus High Speed enables swift work progress even at low temperatures.
Some of the additional features of the new formula improvements are hugely beneficial to any architect, contractor and for the installers. The FIS V Plus now has an ETA approved service life of 100 years. Meaning peace of mind for all planners that choose it. The physical bond strength of the product have been improved by up to 45% giving this power resin a huge increase in load capacity versus market equivalents. One tip for the installers or contractors would be that the resin can now be used in water flooded holes allowing for continuous use even in damp or wet conditions and reduced edge and spacing distances meaning improved flexibility for problem solving solutions!
One perfect example of a typical re-clad chemical anchor application was the Lions Farm Estate project in Oldbury that Fischer had the pleasure of being a part of. This project was one of the first major re-clad builds in the UK and required the highest performing fixings and the latest materials to make sure the re-clad of the old 1970s building conformed to all 2020 safety standards. The residents of the towers at Lions Farm remained in situ during the build phase so all the supply chain had to work to “just in time” to keep the resident disruption down to a minimum.
Fischer decided to trial the newest formula of their FIS V Plus on the build. The product had already been through thousands of hours of testing and it was time for real life applications to be started.
Firstly the whole subframe system had to be attached to existing brick work. Due to the age of the building and the substrate itself it was clear that a chemical solution was required. However, to attach the subframe, in this instance, wasn’t as simple as a standard application. The Fischer FIS H Mesh sleeve that sits around the threaded bar had to be used to ensure maximum hold and keep the fixing secure within the brickwork.
The project itself was a huge undertaking and there were many different parts of the build that fischer was involved in during the build window. However, the chemical solution that Fischer provided, tested and trained to install was what made it stand out.