Concrete Laitance Removal
What is Laitance?
Laitance is a fine layer of dust or aggregates caused by over finishing the surface. The over addition of water to the screed can cause small particles to rise to the top, worsening the occurrence of laitance. It can also be exacerbated by over trowelling or by rainfall during curing. Laitance has been known to increase the likelihood of a screed surface curling or cracking. It is important to professionally remove this aggregate layer to ensure proper bonding of any furthers layers or the application of a finish to the screed surface.
Why is Laitance Removal important?
If laitance is left in place, over time it will wear down, loosening the bonding of any floor coverings or the surface finish. It is particularly important to removal laitance in areas of high foot traffic or where large temperature fluctuations are expected. Prevention of laitance formation is preferable to removal or treatment of the surface. We will always work to miminise the occurrence of laitance in all of our screed installations and professionally remove laitance before the bonding of a floor covering or the finishing of the surface. Laitance can cause screed to curl or crack and therefore needs to be removed prior to any further construction or the application of load or foot traffic.
How is laitance removed?
Grit blasting is an effective and speedy method to remove laitance from the surface of all types of screed application. Steel abrasives are propelled at the surface at high velocity, blasting away laitance and leaving a rough surface perfect for the bonding of floor coverings. Grit blasting is an extremely quick process and can prepare up to 1000sqm of surface a day. As it is a dry process, there is no need to stop screed laying or other construction tasks in the vicinity.
This method, also referred to as concrete planing, uses a machine with rows of tungsten teeth to smooth the surface of the screed and remove the surface layer of laitance. The effects achieved are often excellent, and this method enables the removal of much thicker layers of laitance than other methods. Smaller planing or grinding machines can be utilised for edgework and detailing to create a uniform surface for finishing or bonding.
This method of surface preparation and laitance removal is for heavy duty applications. A scabbling machine, consisting of a hydraulically or pneumatically powered ram is tipped with metal points to roughen the surface of the screed and produce a finish suitable for heavy duty applications.
Flow Screed Services are here to help you find the method that is right for your needs and budget. Laitance removal is an integral part of our full screed installation service, and we are also available for removing laitance on screeds installed by other contractors. We are experts in laitance removal in London or Surrey and the surrounding areas.
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