That’s a great question! One that thousands of Project Managers and Planners will want to know the answer to. In this short article we at BECOSAN® try to give you some useful information that will help you answer that question.
How long is a piece of string? Yes of course your own situation is different to everyone else. Your floor has many bolts sticking out of it, there are holes and cracks to fill, there is an existing layer of damaged epoxy to remove, joints need to be filled etc. Here in this article we will give some rules of thumb for planning your refurbishment project based on our many years of experience here at BECOSAN®.
We live in a time of renewal. A time to start again. A time for new projects and new ideas. As always, we will start from the ground up and the first thing we will need is a fresh, new and shiny concrete floor. As an example we will imagine a 20,000m² floor that was previously coated with epoxy resin, has many bolts protruding from the surface, there are many cracks and holes and the mortar used to fill the expansion joints has crumbled to dust. When everything is ready you require an attractive and durable polished concrete finish. Here we go.
Bolt Removal. Your old concrete floor was used in manufacturing or as a warehouse. There are bolts sticking up everywhere. The bolts must be drilled out and the holes filled with mortar. Some bolts are easier than others but on average an experienced operator can remove on average 60 bolts per day. Our floor has 300 bolts poking out so our estimate is five man days.
Removing epoxy coatings and line markings. The floor has a coating of epoxy covering the whole 20,000m². It is delaminating and flakes of epoxy are widespread. Also there are many painted markings. These must be removed through grinding using a specialist grinding machine. This is a slow process and another good reason to avoid epoxy floor solutions. One operator with a grinding machine will remove 300m² per day of coating. For our floor we have a team of five people with a grinder each so we need 13 days.
Patching up holes. Holes caused by impacts or repetitive wear have to be filled. This is much, much more difficult to estimate as no two holes are exactly the same. Some holes are a few centimetres across and couple of cms. deep. Other patches can be a few meters in surface area. For estimation purposes we estimate a repair rate of 2m² per operator per day. Fortunately, large holes are rare and on our floor we only have a couple of dozen smallish holes covering about 10m² and we have allowed five man days to do the work.
Repair cracks. Next, we must clean out and fill cracks in the concrete with an epoxy mortar. One suitably experienced operator can repair 75m of crack per day. Our floor is fundamentally sound and we only have about 690m of cracks and our team of five will have this done in less than two days.
Sealing expansion joints. Expansion joints are pretty much the same as cracks but because they are straight, regular and even depth, we can do this quicker. A BECOSAN® operator can reseal 150m of joint per day. On our imaginary floor we have 7,000m of expansion joints so our team of five will need just over 9 days to complete the job.
Removing micro roughness. Now at this stage some owners will mean to recover their floor with an epoxy coating. However, we recommend a better, cheaper and long-lasting solution – The BECOSAN® System. The first stage is to grind the floor to a smooth finish using grits graded progressively from 50 to 200. Then we treat with BECOSAN® Densifier. Using the latest ride on power trowels one operator can process 2.000m² in one day. A team of four with two ride-on power trowels should be able to process our floor in about 10 days.
Polishing to a high gloss. There is no reason why your floor can’t be beautiful as well as functional. To give a smooth, shiny floor that is highly resistant to liquid spillage we polish the floor with grits graded from 400 to 3000. Then we apply BECOSAN® Protective Sealer to make the floor the best it can possibly be. Once again, a single professional can treat 1.500m² in a day meaning that the final step for our 20,000m² floor will take another seven days with a team of four with two ride-on power trowels.
So, we have removed the bolts, ground away the old epoxy finish and industrial markings, sealed the cracks and the expansion joints and polished the floor to a high gloss finish. On a 20,000m² floor we estimate that it will take about 200 man days to finish the work. This over an elapsed time of approximately 40 working days. Note that over a third of the effort involved is the removal of the old epoxy coating. Using the BECOSAN System the life of the floor will be extended significantly and you will never have to remove the epoxy coating ever again.
In this article, we have given you some numbers to play with in your project plan. Note that every floor is unique and these numbers will not hold for every situation. If you would like a quotation then contact us at BECOSAN. Better still allow us to process a few square meters of your concrete floor and we will show how wonderful that floor can be.