CD Designs Blog

    How much ice do you need…before you call in an ice breaker?

    We’ve already talked in previous concrete driveway blogs about methods you can employ to de-ice your pattern imprinted concrete driveway or patio. These are easily manageable for a small residential setting. But think about what it would be like if you had to keep a whole road system de-iced and operational?

    For example, a twenty mile section of the M8 Motorway in Scotland was completely frozen under compacted snow and ice last winter, leaving hundreds of motorists stranded. This kind of problem becomes more commonplace in the UK each year, with increased numbers of cars on the roads, and harsh winters to contend with.

    The two maintenance firms that deal with the majority of Scotland’s roads, Amey and BEAR Scotland, have stockpiled a total of 52,000 tonnes of salt and other de-icing material to ready themselves for this year’s winter. So you know if you leave your pattern imprinted concrete driveway this winter and head out on to the roads of Scotland the agencies should have you covered.

    And it doesn’t stop there — a gargantuan icebreaker machine has been been shipped over from Scandinavia to join the hundreds of snow ploughs, gritters and other vehicles that will wage war on Scotland’s ice problem this winter. We’ll be rooting for them!

    How Rock Salt and De-Icer can Damage your Pattern Imprinted Concrete Driveway

    We have talked a few times about how your pattern imprinted concrete driveway can suffer from damage at the hands of salt and de-icer. Here we’ll talk a bit more about how this happens.

    First, the basic way de-icer works is to form a brine by mixing with the water in ice and snow. This brine has a lower freezing point than water, so continues to melt the snow and ice until it becomes too diluted to function effectively. The trouble is that this brine can seep into concrete, especially unsealed porous concrete. As temperatures get lower, the brine can refreeze, which causes cracking and other damage to the concrete. In the spring, you may experience a continuous freeze and thaw cycle, which can cause much more serious damage.

    Second, rock salt will dissolve in the moisture left behind as it melts snow and ice. It too can then seep into your concrete, and when the climate becomes warmer and the moisture evaporates, the salt will recrystallise, causing the surface of the concrete to spall, or flake off. The process is also known as sub-florescence.

    Third, if rebar metal is present in your concrete, you can face another problem – the de-icer and salt can corrode the metal, and the corrosion process can exert pressure on the surrounding concrete, making it crack and break down.

    To mitigate such problems, we would advise that if possible, you shouldn’t use salt and de-icer on your concrete driveway or patio at all. If you think you’ll need to, make sure your concrete is sealed properly, to cut down on the chance that brine/liquid could seep into the pores. And make sure you use small amounts as needed – don’t saturate the area with de-icer or salt.

    Can We Mention Snow Yet?

    Ok, ok, we probably need to apologise for this one immediately, before we go any further. You’ve just about got over the rainy summer (it was in the grim North, anyway). You are hoping for a windy but hopefully not too wet autumn. And then the folks over at CD Designs go and start banging on about winter weather already? Despicable, some might say.

    But hold on there — it is certainly not our intention to attempt to condemn you to an endless winter. We just wanted to share a few nuggets of advice to prepare you for the cold spell.

    For a start, make sure you get yourself a decent shovel: this has endless uses, from the obvious (shovel that snow), to the more inventive (shovels are also good makeshift toboggans, if you have a decent wide, flat one.)

    Next, you should think carefully about what you use for grip on your pattern imprinted concrete driveway. Using sand, or a sand a gravel mixture is ideal, as it provides grip when the snow falls, then you can simply wait till the snow has melted and shovel it up and re-bag it, ready for next year. Using Salt on your drive is not a good idea, as it can corrode your concrete.

    Can You Concrete in Winter? Sure!

    Although concrete is more often than not installed during the warmer months, it can indeed be poured, imprinted, set, and cure successfully during winter. Obviously, the process is a little more complicated than pouring in “ideal” weather (warm and dry), but it’s nothing that can’t be sorted out with some know-how and a few extra pieces of equipment.

    Temperature affects the speed of the chemical reaction which makes concrete harden. At high temperatures (20C+) there is a risk that the reaction will take place too quickly. During winter the reverse is true; concrete laid without the necessary additional precautions could harden too slowly, and freshly poured concrete definitely shouldn’t be exposed to temperatures below 4C.

    The problems that arise from installing concrete in winter can be solved through a combination of and awareness of a number of things. First (and this, to be honest, is just common sense) concrete should never be poured directly onto snow, ice, or frosted or frozen ground.

    Secondly, the concrete being poured in winter usually has a slightly drier mix than normal concrete. This “low slump” mix helps to minimize any risk of complications through bleed water, and water in the mix as it sets, freezing due to low temperatures.

    Thirdly, attention needs to be paid to the finishing of the concrete, so no water remains on its surface. This is an important stage in any concrete installation, and one in which you’ll definitely reap the benefits of using skilled and experienced contractors.

    Finally, after concrete has been laid and finished, and if the temperature is low enough to make it necessary, it should be protected by covering it with plastic sheeting and some form of insulating material, ideally dedicated insulated blankets fit for the task. This will allow the concrete to cure properly, and ensure that consistently low temperatures don’t retard the hardening process that gives concrete its impressive strength and durability.

    Winter Concrete Driveway Care

    Although concrete is remarkably durable, it does require a minimal amount of care. After your concrete has been installed, and any cosmetic procedures – staining or pattern imprinting for example – have been completed, it must cure and then be sealed. This sealing will usually be completed by the contractors; make sure that it happens.

    Concrete can sometimes be susceptible to damage caused by absorbing liquids and/or chemical products. Salt and calcium chloride are two of the main chemical contributors to cosmetic damage. It’s impossible to avoid your driveway coming into contact with these two substances, but by properly cleaning (using a low-pressure stream of water) and caring for your driveway, the situation is entirely controllable. You must take care to reseal your concrete every 1 or 2 years; by doing this you safeguard against potential surface wear and tear.

    There are a two other things to look out for:

    During winter, you should be careful not to allow snow or ice to build up on your driveway.

    You should make sure that you don’t apply or spill any de-icers which contain ammonium sulfate or ammonium nitrate onto the surface of your concrete, as they will damage it. Some garden fertilizers also contain these chemicals, and so should be kept off your concrete, as should fertilizers containing urea. Although ideally your driveway should be kept free of any de-icing compounds at all during the first winter after it has been put down, during subsequent winters non-damaging de-icers can be safely applied.

    Complete Driveway Designs Ltd

    The Yard, Stubbins Lane, Ramsbottom, BL0 0PT
    T: 01706 827180

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