It is important to note that all concrete will shrink slightly as it dries. Consequently, when it’s set, it will continue to expand or contract depending on the ambient temperature. Concrete can expand up to a half-inch (1.27cm) per 100 feet (30.48m). Concrete expansion is natural and expected during the warmer periods. By installing expansion movements joints in the concrete slab, it helps to protect the screed floor from cracks.
Should too much strain be placed on the floor, cracking will be located along the line of the joint, in a controlled manner. However, without the joint, the cracking could be spread across a wide area.
Mirroring Through Expansion Joints To Prevent Cracking
When laying any resin screed the technique of mirroring through the joints is an important step. This is because joints in a concrete substrate are created to control the shrinkage and expansion of the slab, in order to minimise cracking.
Epoxy resin does have some degree of elasticity; however, most will not be able to cope with bridging expansion joints. To avoid cracking and delamination of an epoxy resin screed floor, movement joints need to be mirrored through the final floor finish.
Creating An Aesthetically Pleasing Expansion Joint
It is important to mark out the expansion joints prior to the resin floor installation. Once laid the expansion joints will no longer be visible. After the resin floor is cured, we use a chalk line to mark out where the expansion joints are. Additionally, they can be re-cut and knocked out. We then fill the void with a matching jointing compound to achieve a more aesthetically pleasing, neat, and higher quality finish. If left unfilled, the void will collect dirt and debris, which is not only unsightly but could also cause the joint to shear. Concrete moves, and debris could limit expansion.
Related: Keep On Trucking – Why Are Trucking Gangways Important?
Leading Edge Labels Ltd – Engineering and Manufacturing Flooring
Leading Edge Labels and Packaging of Gravesend is an existing PSC client. Based in Kent, they are one of the largest HD Flexo packaging printers in the UK. They supply to household, personal care, food, beverage, beauty, healthcare, petcare, horticulture & automotive industries.
Furthermore, they operate a 24/5 multi-production facility with 10 enormous printing presses. Therefore, it was imperative that the work was carried out to fit in with the client’s working schedule. As well as, creating as little dust as possible. The 201 square metre area was covered with laytex screed and failed floor paint which had to be removed. After that, the final nominal 3mm self-smoothing epoxy resin screed floor could be laid.
In Preparation
Firstly, we used a totally enclosed double-headed diamond grinding machine, which required power supplied by a 3 phase, 415 volt 32amp power supply, to remove the latex screed and failed floor paint, and thoroughly clean and prepare the existing concrete floor.
Then, we prepared all edge-work using a totally enclosed handheld 110v diamond grinder and vacuumed the area to remove all residues and dust. We also carried out repairs to localised damaged concrete as required using resin screed.
After that, we applied two coats of Resdev Pumaprime epoxy resin priming system to the total floor area to prevent air rising. After that, the nominal 3mm Resdev Pumaflow self-smoothing, epoxy resin screed, in the clients chosen gloss, mid blue.
We mirrored through, recut, knocked out, and infilled 3mm x 6mm expansion joints with matching jointing compound to approximately 35 linear metres.
Another Happy Client
On time and within budget, Mr Dave Driver, Operations Director – Leading Edge Labels Ltd commented:
“We have used PSC before and find them extremely accommodating and helpful. The floor has once again turned out exactly as we wanted. Happy to recommend them as a company and use them again in the future.”
If you enjoyed reading this blog, why not take a look at a previous one: Fit For Forklifts – Warehouse Flooring
