利用者:MackGiffin574
Polished concrete is strong, durable and low maintenance with that earthy texture of stone having a polish comparable to granite. Here is how it is done.
It's just like traditional polished terrazzo which is very flat and poured as a special mix to create the conclusion more productive. Polished concrete floors can also look almost bumpy and have little or no aggregate showing. Flatness and polishing aren't necessarily the same thing that is a good point to clean up before acknowledging any project.
It is extra time and diamond wear to chop floors with a concrete grinder until they are flat. They are able to be either ground flat to fully expose the aggregate like terrazzo, or even the aggregate could be partially exposed, or even the concrete grinding can expose a maximum of the fine sands at the surface. Many times, it takes skill and experience to control the entire process of polished concrete floors and the quality of the concreter's original laying work is additionally a contributing element in the caliber of the conclusion. In which the aggregate is a feature special materials could be put into the wet concrete mix for example coloured pebbles, metals and glass to boost the final appearance.
Most people are unaware that there are 10 to 15 steps for polished concrete floors which takes a long time to accomplish and can be very costly.
Typically it takes many grinding passes to finish a highly polished floor although there are also ways as explained later. The overall rule would be to double the diamond grit size underneath the concrete grinder for each pass so a contractor might start with very coarse, 16 or 32 grit size diamonds, then use 60 grit diamonds then 120, then begin anew with a 50 grit diamond resin pad instead of a metal segment. While using resin pads the steps might be 100, then 200, 400, 800, 1500 and lastly 3000 grit. That would be ten separate grinding passes which does not count the two other essential steps.
Two more essential steps:
1. Hardening the surface
Polished concrete floors usually have the surface hardened with a chemical prior to the second, third or fourth grinding pass. Caffeine soaks in to the floor to a couple millimeters (up to half one inch) and causes a chemical reaction to occur that makes the ground harder and simpler to shine to a high finish. These floors are very resilient and strong without getting a surface coating.
2. Filling holes
After the first concrete grinder pass removes the very best layer of concrete paste it will expose countless tiny air holes. If these aren't filled prior to the hardening process then your final polished concrete floor can have these unsightly imperfections. The holes are usually filled with a polymer tile adhesive type of product mixed with either the grinding dust or cement powder which is hand scraped across the floor utilizing a trowel. The most well-liked method to fill the holes would be to spray the acrylic adhesive ahead of the grinder so that the diamonds mix it in to the holes with the grinding dust on the third or fourth pass at around 120 grit. This method is faster and the dust matches the colour from the floor to hide the holes better than when utilizing cement powder.
Very flat or slightly bumpy polished?
Some floor grinder machines are made to create a very flat floor by cutting off our prime spots although some other medication is designed to stick to the contours from the floor more. When the surface will be polished without necessarily exposing the aggregate then only the finer resin pads have to be utilized on a concrete grinder that enables for movement from the pads to allow them to follow the contours of the surface. This will create a polished floor without showing the pattern and texture of the exposed aggregates within the concrete which is faster and less expensive. Hardening can still be a benefit to help the sturdiness from the surface and also to produce a final gloss.
Issues with exposed aggregate
Sometimes the conclusion of exposed aggregate can be uneven if the mixture of concrete was poured unevenly or completed poorly. Boot marks or kneeling board marks can appear suddenly simply because they have pushed the aggregate down further which might require grinding down another two or three millimeters (quarter of an inch) that will are more expensive than was quoted. Grinding this far might not be exactly what the customer wanted either so it could be a risk.
Single head or multiple head machines
Original terrazzo grinding was done with single head floor grinders until the manufacture of three-head planetary machines. Planetary implies that each head turns one direction as the turntable that houses the heads turns independently in either the same direction or the other direction. Some grinders can differ the direction of both the turntable and the heads plus some can vary the speed of each. There are also multiple head planetary machines with four or even more heads.
The planetary heads can stick to the contours much better than single or twin head grinders and are faster to use with less effort due to eliminating the requirement to physically move the grinder from side to side or perhaps in a circular motion. Single head terrazzo grinders should be moved inside a circular motion to avoid grinding lips or shoulders.
Edging
As with wood flooring the perimeters must be finished separately towards the main floor area since the large machines may bump and damage the walls if they're used too close. For that first grinding passes a nine inch angle grinder can be used having a diamond wheel attached with a dust extraction shroud suited to remove the dust. The sit-down-to-use edge grinders tend to be more controllable than fully stand up grinders while kneel-to-use grinders have good control, but they are exhausting.
After the first two or three cuts another dust extraction shroud with a corner feature can be used having a seven inch polisher or perhaps a five inch, multi speed grinder to polish with resin pads and get tight into the corners.
Simple polished concrete floors "look"
The amount of processes for polishing concrete could be reduced by as much as 60% and still acquire a similar appearance by grinding after which coating with a clear sealer. The initial step is to grind with 30/40 grit diamonds to expose the aggregate, then fill all of the small air holes as described above (in Ten to fifteen steps....) before another grind with 60/80 grit or 80/100 grit diamonds.
This can create a smooth enough surface to coat with a sealer. Polyurethanes are very hard sealers with a glossy and could be purchased as UV stable to stop yellowing (usually double the amount price of non UV stable urethanes), clear epoxy sealers are not as smooth and can chalk and deteriorate if subjected to sunlight and acrylic sealers have a shorter lifespan due to their poor potential to deal with wear. Two coats are necessary use a high gloss level.
Different ways to achieve "polished concrete"
The first is to chop the ground with coarse diamonds until all of the high spots have been removed to make a flat floor after which make use of all from the 12 to 15 steps to eventually polish it or as it is sometimes called, hone it. This is the true polishing system.
A variation of the above is to cut perhaps 1 / 2 of the height from the higher peaks by beginning with a medium coarse diamond grit and proceed through to polishing using a machine that may ride up and also over small rises.
Another alternative route of manufacturing a honed surface is to begin with relatively fine diamonds and simply polish to top of the surface after hardening without removing a lot of the top cement paste. It is easier to do this once the floor continues to be laid flat and smooth.
Lastly, a "polished look" can be obtained by grinding with coarse diamonds after which fine diamonds before coating over and done with a definite sealer.
Only truly polished floors will retain their gloss with little maintenance because all coatings scratch with wear and lose their high shine. Special buffing pads on a standard floor polisher which contain very fine diamonds can be used to maintain cleanliness and the glossy amounts of true polished concrete. Janitors could be supplied with these and keep the floors in great condition without special treatment.
Some hire companies provide the grinding equipment for do-it-yourself concrete polishing and also have all of the pads for the purpose. It isn't really so economical though since the pads may be only half worn when you finish depending on the area involved.