If you are thinking of grinding and polishing a concrete surface, it’s wise to think in advance about how this surface can be protected through every stage of the process. Achieving a polished concrete floor is a very laborious task. There are lots of stages of planning; making sure the correct type of concrete is ordered, making sure it is laid and cured correctly and the installation is problem free. Not to mention organising getting the polishing work done and planning in other trades around that schedule.
It’s also a considerable investment in time and money and when this much effort is put into getting something done correctly the last thing you want is for something to happen to put paid to all of your hard work.
I cannot stress enough how important it is to protect your surface from damage both while the concrete is curing and after it’s been ground and polished. Arming yourself with plenty of information regarding protecting polished concrete surfaces should be a high priority of everyone interested in installing this type of decorative flooring.
All concrete flooring, particularly decorative concrete, has long been thought of as being quite indestructible and able to withstand a barrage of abuse from many different sources. This is simply not true. That’s not to say it’s not a very durable flooring solution for many applications and this is why it’s very popular right now in many residential, commercial, industrial locations and office buildings. Even durable materials require some degree of protection and maintenance.
However, I’m sure you couldn’t imagine purchasing new furniture only to ruin it with spills, stains and misuse? In this article we’re going to talk about the things to consider which may spoil the look of your concrete and how you can protect it.
When Concrete Is Newly Laid
Concrete that is newly laid is very vulnerable to many things. When it’s curing, we recommend the concrete be covered over with a layer of plastic sheeting which will not only keep the surface clean but will prevent the moisture from escaping from the surface too quickly. Controlling the moisture and keeping the surface wet will promote a stronger, less porous slab and prevent the concrete finish from looking dry and dusty.
It’s important to make sure that the plastic sheeting is laid flat and kept smooth as creases within it can cause curing lines in the slab’s surface. Curing lines look like darker marks on the face of the concrete which don’t match the rest of surface in colouring. They can’t be removed by dry polishing or using abrasives.
Once the plastic has been secured into place, we at CARRcrete recommend the use of Corex corrugated sheets over the top which will then provide hard wearing flooring that can be used without worry by other trades people carrying out their work.
Many other tradespeople don’t think about floor care as they’re working and while, as flooring specialists we don’t like this, we do understand it. Imagine the potential contamination generated by subsequent tradesmen while using products such as gypsum plaster, paint or varnish. The staining their tea and coffee breaks can cause, debris from high levels of foot traffic and scratches from unwanted abrasion caused by grit and stones etc being brought inside from underfoot. Let us not forget also the muddy clay covered floors from building site footfall; always a recipe for disaster! Stained concrete is not what you want to see left behind.
After a 28 day curing period, the plastic sheeting can be removed and replaced with soft painters dust sheets. The corex sheets should then be placed back over the concrete to protect it then until it’s time to create your polished concrete floor.
Concrete Is Not Indestructible And Is Easily Stained
From our experience it is clear that concrete is misunderstood to be indestructible. Lots of clients do believe that it is unbreakable, won’t chip or dent and will often not even stain. We certainly can’t argue that concrete can be an incredibly strong medium to work with, especially when you’re comparing it to other flooring types such as wooden floors, tiles or lino.
What is widely misunderstood is that concrete is actually a very porous material, which is caused by the multitude of aeration holes within the slab, created by the random way that concrete is mixed and laid. When a surface is porous it will instantly want to ‘drink’ any spill that lands on it. Often there isn’t even time to mop the spill up as by the time you’ve fetched a cloth the liquid has already been drawn into the concrete’s mass.
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Many people believe that staining is repairable through grinding but sadly this is often not the case and it all depends on how far into the slab any spills have been incorporated. As we only grind a maximum of 3mm - 4mm from the surface and liquid that has been impregnated into the concrete mass further than that will still remain, it’s always preferable to prevent this from happening in the first place.
When faced with concrete that has been damaged in some way, it is very difficult for us as professional polishers to find a solution that improves the aesthetics of the concrete whilst still maintaining the finish that the client has asked for. This is often something that is not possible so there has to be a compromise somewhere which is highly disappointing for clients and something we don’t want them to have to face.
How concrete densifiers and sealers are invaluable
At CARRcrete, the use of concrete densifier or hardener is included in all our concrete polishing process as standard. Concrete densifiers are a key component in protecting your concrete as they work directly not only to strengthen your concrete, ultimately giving it a better polish, but also to tackle the issue of porosity and therefore preventing spills from being drawn into the concrete surface.
Concrete densifier works by creating a chemical reaction. It penetrates into the concrete, converting the source of free lime and crystallizing over time within the aeration holes to reduce the level of porosity. Our CARRcrete PROhard densifier, that is available to purchase via our online store, is the same one we use while we’re on site and we find it to be the best of all chemical densifiers we’ve worked with.
Using this in conjunction with a quality sealer is a double whammy approach to protecting polished surfaces against wear and tear. There are two types of sealant that we use regularly, both of them offering excellent stain protection but offering slightly different benefits to our clients.
CARRcrete PROseal is a solvent based, fully impregnating, invisible sealant. This product will fully soak into the surface material and will not change the look of the concrete or enhance the floor colour. This is our most popular anti-stain protector and the one that is used in the majority of applications. It truly is an exceptional sealer that produces amazing results.
If you’re planning on polished concrete in a kitchen or dining area, you may prefer to opt for our CARRcrete PROguard sealer. This is a part impregnating part topical, water based sealer. What this means is that a very thin residue is left on the surface of the concrete floor and this is highly beneficial in giving extra protection against acidic or chemical spills. Many foodstuffs and liquids in a modern kitchen are acidic and this sealer will give additional reaction time in order to mop these spillages up. Being water based it’s also sometimes preferable where the solvent smell of PROseal would be unwelcome.
Etching Of Concrete Surfaces Is A Major Problem
Sealed concrete floors are at a much lower risk of damage than an unsealed concrete, however if an acidic substance is allowed to linger on a polished floor for too long, it may start to penetrate and etch the surface of the concrete. You will know if the concrete is etched as any sheen will be gone and there will be what looks like a white burn mark apparent where the damage occured.
The main culprits for damage in the form of etching of the surface are from gypsum plaster, drywall adhesive and coving adhesive while works are still going on at the property. When in use orange juice, sauces and fizzy drinks tend to be the most common culprits.
All of these products if left in contact with the cementitious concrete will chemically burn the surface, forcing you to either grind past the etch or cover with a micro topping such as CARRcrete MicroFloor.
Stains Can Sometimes Be Removed By Grinding
Admittedly by grinding past the stains and/or etching you can in many cases remove the problem areas, but in doing so you are creating an aggregated InfinityFloor Stone application, similar to terrazzo floors in looks. Not every customer would be happy to live with this.
If you have requested our InfinityFloor Cream finish, surface protection is imperative. InfinityFloor Cream is an industrial looking floor finish generated by power trowelling the concrete surface to push down sand and aggregates away from the surface. This leaves a stylish swirled appearance with no aggregate showing through and it is very susceptible to damage prior to our polishing process.
In fact, both our InfinityFloor Cream and our InfinityFloor Salt:Pepper finishes would change dramatically if we had to grind the surface to remove etching or staining. InfinityFloor Cream is a no stone look floor and using abrasive diamond tools on the concrete material, even lightly tends to expose stone to some degree and expose sand particles. If you have imagined and planned on a no stone floor construction then the last thing you want at the end is a diamond grind and a floor that looks like terrazzo or cement terrazzo. It’s not what you have asked us to provide and you shouldn’t have to settle for it if it’s not your style.
Protection After Floor Has Been Polished
If you find yourself in the position where you still have other works to be completed once the polished floors are completed, you will need to cover up the floor completely and protect it from the work of other trades.
Paint, varnish, silicone mastics, PVA primer and of course tea and coffee are all potential hazards to a newly polished surface and used widely on building sites. As we’ve mentioned before, the protection of the floor is not usually the top priority of a general contractor when he or she is working, but it is the priority of the concrete polisher or indeed any contractor in the business of providing decorative concrete flooring.
Again the floor should be covered over with one and potentially two layers of soft dust sheets. On top of these a further layer of corex corrugated sheets should be placed and these should be taped together in order to cover the dust sheets completely and protect against heavy footfall. This should also maintain the sheen on the concrete too whether you opted for a matte finish or a high gloss shine.
Maintenance of polished concrete floors
While not particularly hard work, a schedule of polished concrete maintenance does have to be in place as you would expect, in order to keep the surfaces free of dust and debris and to keep the flooring looking good with a good gloss level year after year.
I mentioned earlier in the article about ‘reaction times’ and this is a really important point as there isn’t one product, system or sealer on the market that will protect the concrete from any spill or any substance if it’s left to linger on the surface for a number of hours. To this end, it’s important to implement a low stress cleaning routine that will keep your concrete is tip tip condition.
We recommend that you use a separate wet and dry microfibre dust mop. The floor should be dry mopped daily in order to remove any surface dust and debris that may be collecting and a wet mop using a ph neutral cleaner, such as our PROcare product, should be undertaken weekly, or as needed.
Always Protect Concrete That Is To Be Polished
So in general basic terms, if you have a concrete surface that you are to have diamond abrasive polished, please cover and protect from damage before your polisher arrives on site. It doesn’t matter if it is a concrete floor, worktop, furniture or stairs; they can all be damaged by neglect.
The protection needs to continue once the polishing is completed, particularly if there are going to be other works ongoing after we, as polishers, have left site. Plaster, paint and silicone are commonplace in construction but have no place on a newly polished floor.
Our team at CARRcrete will help you throughout the whole process and provide you with a comprehensive Floor Care Guide when your works are completed. We are also on hand to offer aftercare advice as and when you need it. Please feel free to contact Simone and her team if you have any questions regarding the protection of your concrete floor, we’re only a phone call away!