Common Questions About Concrete

Our Most Common Concrete FAQs

If you’re in need of decorative driveway or patio work, you must have a myriad of questions on concrete: what works, what doesn’t, what’s most durable, and what look the best. This is an informational article on a few common concerns that are raised when working with concrete. We’re going to give you some helpful information to save you some costly trial and errors and help you achieve the decorative concrete look you’re going for.

Do Concrete Driveways Need to be Sealed?

Though many people believe that concrete driveways don’t need to be sealed, the opposite is true. Sealing your concrete driveway is comparable to waxing your car; your driveway’s lifespan and appearance will be greatly improved. You need to seal your concrete driveway after the concrete has cured and then once every four to five years after that.

There are a variety of concrete sealers available depending on what you want for your driveway: a glossy finish, a matte finish, slip resistance, or even color enhancement. The sealant does many things including protecting your driveway from fading due to UV and keeping it stain-free. In short, concrete driveways need to be sealed in order to stay looking new and vibrant.

Do Concrete Driveways Crack?

While concrete is durable and heavy-duty, cracks don’t always mean that something was done wrong. Cracks in concrete are extremely common, and sometimes they’re even inevitable. Problems arise when cracks appear soon after construction or grow big and unsightly. Sometimes, they may pose structural problems if they’re supporting a column or other construction on your driveway, but unless they do, it’s advisable to leave them be.

This is because repairing cracks with patches or injections may make them look worse than they did before. And if you have panels, then replacing one or a few of them will likely be visually unappealing bacause it will be hard to match the color of the surrounding ones which have aged naturally.

Heat, large tree roots, settling ground beneath, overloading, and premature drying are the most common causes for cracks in driveways so if you can avoid these, you are likely to have fewer cracks on your driveway.

Do Concrete Driveways Need Expansion Joints?

Expansion joints are used to allow concrete slabs to move and not to put stress on whatever may be next to them such as another slab, a swimming pool, or a building. Therefore, concrete driveways may not need expansion joints unless the driveway leads up to a garage or similar hard pavement structure.

The necessity of expansion joints is also dependent on whether the length of the driveway is longer than 45 meters. The climate plays a role in this as well because extremely hot areas will make the concrete expand and when you combine this with heaving of the ground when water seeps underneath it, you get a lot of movement that may lead to cracks. This therefore makes expansion joints optional for your concrete driveway.

Do Concrete Driveways Need Mesh

It is advisable to have heavy-duty mesh as reinforcement for your concrete driveway if you want to avoid cracks. Rebar (steel bars) can be used for this but on a residential scale, it is a bit too much and mesh is the most suitable alternative. They are great to use because:

• They’re more affordable than rebar
• They’re easy to place in the desired position
• They come pre-assembled, so it’s fast to position them
• They have high tensile strength and are exceptionally durable
• They are a consistent size and stay in position while concrete is being poured

While cracks may still occur, the material will all be held together and the weight of vehicles will be evenly distributed on your driveway giving it a longer lifespan. As long as you use good-quality, galvanized, welded, stainless-steel mesh, you will find it easy, fast, and worth the price of getting a driveway that is up to standard.

Can Concrete Driveways be Resurfaced

Concrete driveways can be resurfaced, and it is cheaper and faster than demolishing the whole thing and replacing it. While concrete driveways are fairly durable, a few things that can make it wear out fast are:

• Exposure to extreme weather conditions
• Using an inadequate concrete mix
• Bad placement procedure
• Not compacting the subgrade properly

If a professional tells you that the concrete’s structural integrity is sound, save money with a driveway concrete resurfacing process that will repair, stain, and redecorate your driveway to breathe new life into it. More damage and bigger cracks to the concrete will require a bit more work to be done before the resurfacing itself begins (such as filling small cracks and cleaning oil stains) so that your final work is long-lasting.

Can Concrete Driveways be Painted

Concrete driveways can also be painted in order to breathe new life into them. You simply need to get the right grade of concrete paint which will extend the life of your driveway because paint will help slow down cracking and chipping due to exposure to extreme weather.

The process is pretty simple:

Clear your driveway of things such as planters and decorations; place them somewhere they can stay until the paint has dried.

Next, sweep the driveway with a broom to get rid of dust, leaves, and other fine debris. You can also use a blower to make sure you’ve cleared the area thoroughly.

Use a pressure washer to make sure you remove any dirt that may be stuck onto the pavement. Alternatively, scrub the driveway to dislodge any dirt and make sure there is nothing stuck anywhere that will introduce an irregular spot after you have painted.

If there are oil and grease stains, you will need to apply a de-greaser to them and then scrub the stains clean.

Tape off the sides of your home and any other things you need to protect from the paint at the edges, ideally with blue painter’s tape. You then need to repair any cracks on the driveway by first scrubbing with a stiff brush to remove any loose debris then filling them in with repair caulk or concrete. If there are holes larger than 0.64cm in diameter, you may need to use a concrete repair compound. After all this is done, make sure to even the surface of the repaired area and make it match the surrounding area as closely as possible so that the repaired areas won’t stand out.

After the caulk or repair concrete has set, prime the driveway with a water-based active etch primer. This binds to the driveway’s concrete surface and makes it rough so that paint sticks more easily to the surface.

Apply a coat of paint then allow it to dry for 24 hours. Then apply a second coat and let it dry for another 24 hours before you walk on it. Don’t drive on it for at least 72 hours to let the paint set completely.

These steps may call for an expert’s help but if you are enthusiastic about taking on the project yourself, make sure you get the right equipment before you start work in order to ensure the best results.

Can You Pressure Wash Concrete Driveways

Pressure washing your concrete driveway can be an effective way of getting stubborn dirt and stains off, but you need to take care. It is advisable to use a power washer with a pressure rating of 3,000 psi in order to clean effectively and be prepared to seal your driveway afterwards. This is because power washing can create visible damage to your driveway if you aren’t careful and this damage is bound to get worse with time.

It is important to note that a pressurized stream of water can be extremely powerful and if used incorrectly, can lead to destruction of property and cause bodily harm. Before you go the route of using a pressure washer, first test if using a small nozzle to direct water from your garden hose can give you the results you need. If this doesn’t work, you could enlist the services of a professional who does pressure-cleaning. If you prefer to DIY, do thorough research on how to go about it.

A few tips to help you include:

First off, practice somewhere other than on your driveway in order to get a feel of the equipment and once you do, clean an area of the driveway that isn’t too visible in case you inadvertently cause damage.

Use a nozzle that produces the pressurized stream of water in a wide angle as opposed to a sharp point as the latter is more likely to cause damage.

As you clean, don’t direct pressure on one spot for a long time but rather use continuous sweeping motions from at least 12 inches away from the surface and with the nozzle at an angle.

If your runoff has detergents, grease, or oil in it, direct the runoff to an area with dirt or gravel  in order to avoid killing your grass and flowers or getting it into the storm drain.

Finally, don’t spray directly into joints between pavers or along the edge of your driveway as this can wash off the sand or grout and affect the integrity of your driveway.

Always seek help when unsure because repairs can be costly and time-consuming.

Does Concrete Conduct Electricity

The chemical components that make up concrete have free ions through which it can conduct electricity. Even so, it is a very poor conductor and can even be considered an insulator as it significantly slows down electrical currents. While it has better conductivity than other materials (like glass and wood) it is still not high enough to be categorized as a conductor.

Wet concrete will also have a higher conductivity than dry concrete but both are lower than wet grass, so you would be better off standing by a concrete wall than in a grassy area during a lightning storm. Increasing the temperature of cement also increases its conductivity as the ions within it move faster when heated up.

In summary, moist, heated concrete can be termed as a poor conductor while cold, dry concrete is a good insulator. Because of this it is used in construction for: protecting against lightning, grounding, environmental heating, and eliminating static electricity.

Can You Repair a Concrete Driveway Cracks

Cracks in a concrete driveway from tree roots growing underneath them, the earth heaving, and heavy loads being placed on them can be repaired quite easily. The best thing would be filling them early in order to stop them becoming a bigger problem in the future. If the rest of the driveway was installed correctly and is in good shape, then it can be an easy DIY project filling in the cracks to improve the appeal of your home. Different types of cracks will call for different repair techniques and materials, for instance:

• Crazing, or very fine surface cracks, can be fixed by applying a resurfacing product that puts a thin layer over the cracks.
• Hairline cracks that are under 1/4 inch wide can be fixed by using concrete crack fillers or dry concrete mixes.
• Cracks bigger than 1/4 inches wide which can be fixed by a concrete mix or patching compound with gravel in it. These cracks will also best be fixed by a professional because they indicate deep damage that may have occurred on a structural level and more work than you can do by yourself may be required.

If you decide to do it yourself, you can use these tips to make the process go smoothly:

• Use kneepads to protect your knees if you will be working over a large area or for a long time.
• Make sure to follow the instructions well to avoid doing double work.
• Allow for the correct curing time. If you want to use your driveway as soon as possible, go for a rapid-set crack-filler.
• You may use textured or concrete-colored products to try and blend better with the existing concrete.

Can a Concrete Driveway be Poured in the Rain

While one can pour concrete in the rain for different reasons, it’s not advisable because the rain can wash off some cement from the mix and compromise the strength of your construction which will encourage dusting and scaling. Concrete normally needs between 24 – 48 hours to set and 28 days to fully cure. During this time, you should avoid placing heavy machinery on its surface or disruptions like extreme temperature changes.

Always make sure to check the forecast so that if rain is predicted, you postpone the cement pouring to a time with less likelihood for rain. If you are working a tight deadline or an unexpected downpour occurs, cover the surface with plastic sheets or tarp to avoid getting contaminants on the concrete’s surface. After the rain has passed, push away any surface water left with a float and don’t dust with additional cement to absorb the extra water because this will lead to the surface being weak and poorly finished.