Driveways are a common feature in most urban home settings. Over time, driveways form cracks due to various factors. This article delves into, why do driveways crack and how to maintain them.
Asphalt Vs Concrete Driveways
When installing driveways, most materials used are similar except the adhesives used to hold these materials together. Asphalt uses bitumen, while concrete uses cement.
These adhesive properties differentiate asphalt from concrete in terms of durability, cost, appearance, and environmental effects, which generate both advantages and disadvantages.
Factors to consider when installing a driveway:
Cost– How much is a person willing to spend to install a new driveway? Here are some tips that can help to answer this question.
• The availability of materials– determine if the supplies required are locally available and how weighty they are. If they are easily accessible and less bulky, the cheaper it will be to install. Concrete and asphalt are easy to find; hence, procuring them will not be costly, but concrete costs more than asphalt in individual worth. Asphalt costs R80 – R150 per square meter, while concrete costs R45 – R100 per square meter.
• Size of property– Contractors examine the square footage of the property to approximate the total price. The bigger the driveway, the more expensive it will be to install. Asphalt being cheaper to buy, one will save a couple of dollars if the driveway needed will be enormous.
• Drainage features– they include features such as gradient, pipes, trenches, channels, and dry wells. The contractor should account for them before installation. Without proper drainage systems, damages will increase the overall maintenance and repair costs.
• Design features– having some additions like lighting and greenery to enhance the driveway’s beauty will increase costs. A good example is that one may want a winding driveway that will use more materials and cost more than a straight one.
Maintenance and repair cost– driveways need to be managed appropriately to maintain a fresh and sparkling glow. It's advisable to pick a product that will be easy to manage. Asphalt is easier to repair than concrete, but it needs to be repaired more frequently than concrete. As for concrete, it requires little repairs after every 5 years, but repairs can be costly.
Climate factors– it is vital to consider climatic conditions when choosing between asphalt and concrete. For areas with heavy downpours, it’s advisable to have an elaborate drainage system that prevents flooding.
Durability– by using high-quality materials with a long-standing span, correct installation procedures, proper maintenance, and a conducive climate, the driveway should last for many decades. Asphalt driveways last for about 20-25 years, while concrete driveways last for 30-40 years.
Asphalt Driveways Pros & Cons
Pros
• Asphalt driveways can be used as soon as the installation is complete. It hardens by cooling.
• Resealing an asphalt driveway is inexpensive, and the homeowner can do it by himself.
• As earlier discussed, asphalt performs well in cold temperatures and also in areas with fluctuating temperatures.
• It’s better at draining water due to its porous nature, inhibiting the formation of cracks, portholes, and invasive vegetation.
• A new asphalt driveway can increase a house's value upon selling since it's easy, fast, and cheap to install.
Cons
• Asphalt is expensive in the long run. It must be resealed on a regular and requires frequent repairs from time to time.
• The use of hot evaporative petroleum products during installation and sealing makes it to be a harmful product for the environment.
• Heavy trucks are likely to form tyre dents on the surface that enhance flooding and the formation of portholes.
• It may break down around the edges due to heat, lowering its aesthetic value.
• It’s not ideal for scorching areas. Asphalt tends to absorb heat, making it extremely hard to walk on.
Concrete Driveways Pros & Cons
Pros
• Concrete can be textured when wet using a simple brush to create a wide range of beautiful patterns that give more fun and inviting look. It’s easy to play around with colors using dyes, powders, and stains to match one’s color schemes.
• Concrete can be expensive when installing, but it can last up to 40 years with proper maintenance.
• Concrete doesn’t require many repairs and maintenance, making it easy and cheap to maintain in the long run.
• Concrete is an eco-friendly product. The recent use of recycled materials to supplement the regular aggregate use has reduced the strain on earthly resources.
Cons
• Concrete doesn’t do well in cold temperatures. It tends to become brittle and cracks easily. It’s also very sensitive to de-icing salt elements, which form shallow pits on the surface.
• When damage occurs, one needs professional help and expensive materials, making it difficult and costly.
• With the lack of a proper drainage system in place and adequate cleaning, concrete can stain due to mold, lichen, and dead leaves, lowering the aesthetic appeal.
• The initial cost of installation is high due to the materials used and also the labor needed.
• It also takes longer to construct and be ready for use as it requires to cure for almost a week.
• Concrete can be slippery during wet or snow seasons, making it dangerous to walk and drive on.
Top 7 Reasons Why Do Driveways Crack (Asphalt Or Concrete)
1) Thermal Expansion & Contraction
Changes in temperature cause materials to either expand when heated or contract when cooled. As earlier reported, asphalt can handle temperature fluctuations very well but to a certain degree.
As temperature increases, the material at the top expands more and more. Still, the aggregate at the base length remains stationary, causing the asphalt at the top to be stressed and eventually crack.
The same also applies when the temperature drops beyond the freezing point, asphalt contracts on top, the aggregate at the bottom is still immobilized, causing it to be stressed and crack.
This phenomenon also affects concrete.
2) Overloading
Heavily loaded trucks will damage the road. Every time a heavy vehicle passes over the driveway, it causes small but significant damages to the concrete or asphalt.
On concrete, they cause huge cracks that are dangerous for human and animal life.
3) Sharp Objects
Broken glass, screws, and sharp car parts are hazardous to driveways, people, and animals. Heavy debris, such as tree branches and rock, tend to leave huge dents that become portholes.
Avoid having giant trees along the driveway as a preventive measure.
Cleaning equipment such as the snow blade severely damages concrete, especially in cold seasons when concrete is brittle.
4) Intrusive Vegetation
There are microscopic cracks that allow water to sip in enabling small weeds to grow. The plants’ continued growth causes cracks to develop as they force their way up the surface.
Tree roots have disastrous and expensive effects on roadways, mostly concrete. They have a greater potential to push through concrete breaking it from the base at several points.
5) Heaving & Foundation Settling
Heaving is a process that occurs when the soil that’s holding up the moisture expands due to moisture or ice, making the foundation to move upwards.
It usually happens when there’s continuous and heavy downpour or poor yard drainage, which saturates the soil, exerting pressure on the foundation, leading to the formation of cracks.
This can be rectified by removing unwanted water and, in severe cases, draining the foundation.
Foundation settling occurs when soil layers holding up the foundation cannot hold up the weight anymore or when the soil moisture decreases, making the base length crack, causing severe damage.
Steel push piers are recommended to fix this problem.
6) Poor Base Installation
A long-lasting driveway is determined by the type, size, and installation technique of the granular base. It’s essential to start with a qualified contractor, and the materials plus methods used should be of high quality.
The use of sub-standard material and thin foundations can result in cracks, depressions, and potholes.
7) Sinkholes
Underground weathering is a common cause of sinkholes.
They form when water dissolves the rock underneath the soil, holding up the foundation, creating a deep fissure causing the layer to collapse in on itself, taking everything with it.
Whether induced or natural, Earthquakes do form sinkholes when they hit an area with a weak rock.
Sinkholes are hard to repair. The void needs to be filled with soil and left for a week to settle, after which it will be safe to lay asphalt or concrete.
How To Maintain Your Asphalt Driveway?
1) Driveway drainage solutions
Prevent accumulation of water on the driveway by having a proper drainage system.
They include slope gradient, drains, landscaping swales, and permeable pavements. If flooding is allowed, water can sip through concrete and freeze during cold temperatures, making it expand and cause cracks.
2) Remove any debris and nearby trees
As discussed earlier, sharp and heavy objects such as glass, screws, rocks, and branches damage the surface.
Tree roots penetrate through the aggregate creating huge cracks. This can be prevented by cutting the roots or removing the tree permanently.
3) Avoid having heavy trucks passing over the driveway
On asphalt, such trucks are likely to form indentations, leading to the formation of cracks and portholes.
How To Maintain Your Concrete Driveway?
1) Clean stains immediately when noticed
Concrete tends to hold on to colours such as oil, mould, and dry leaves. Regularly clean by pressure washing to keep it looking fresh.
2) Use appropriate equipment when cleaning off water, debris, or snow to avoid damaging the surface
Concrete is susceptible to cleaning objects. Do not use salt to clear off ice and snow. It tends to get brittle in the cold seasons, and such harsh treatment causes it to chip and crack.
3) Fill the cracks
Cover the cracks with a crack filler or install expansion joints. these joints help to reduce the pressure caused by one concrete block from being absorbed by the other slab.
Conclusion
Each product has its merits and demerits. Concrete driveways are more expensive to install and repair, while asphalt driveways are a good choice for homeowners on a tight budget. They are also faster to install.
References
1) https://www.bobvila.com/articles/concrete-vs-asphalt-driveways/
2) https://www.thespruce.com/asphalt-driveway-paving-1822355
3) https://atlantisfiber.com/concrete-vs-asphalt-roads-which-is-better/
4) https://www.homeadvisor.com/r/asphalt-vs-concrete-driveway/
