Properties and Benefits:
This is a high-performance multifilament fibre (flock) that was designed for cementitious materials to mitigate early-age crack control in concrete, as well as freeze/thaw cycles, impact and fire resistance.
However, our interest in these materials is for use in lime renders and being able to offer our customers a choice and in providing them with sound honest advice based on many years’ experience in using and supplying them. With this particular fibre Cornish Lime has been supplying it for just over 2 years and are more than happy with its performance. As a “Flock” it differs to many other synthetic types as the base fibre has undergone a “Flocking” process where additional smaller fibre particles are bonded onto its surface creating a greater surface contact area for the mortar matrix.
While many purists scorn the use of modern fibres over that of animal hair, which we absolutely respect, it is our opinion that this type especially, is much more like hair but essentially much simpler to use, and like other types of synthetic offerings they have proven to be an extremely effective and honest alternative to hair, certainly over the 25 years we have supplied and used the various types that we have.
Addition rates will vary according to application, and (FOR GUIDANCE PURPOSES ONLY) can vary from 500g per tonne when used as an aid to control shrinkage cracking on high suction backgrounds, to as much as 2Kg per tonne (of mixed mortar) for rendering onto lath.
Once added into the render they should require only a few minutes mixing but most importantly, they must be distributed as evenly as possible throughout the mix to be effective.