Do resin driveways crack?

* Collaborative post 

Resin-bound driveways are fast becoming a popular choice for homeowners. They have an attractive finish, are highly durable, and are low-maintenance. But can a resin bound driveway crack? Under normal circumstances, no. You shouldn't expect your resin-bound system to crack. But there are some situations where it can happen, and this is often due to poor installation. Here are some tips from Resin Crew.

What is a resin driveway?

A resin-bound driveway is made of clear resin that has been mixed and bound with an aggregate. The aggregates can vary in shape and size, so you can choose lighter coloured stones, darker coloured stones, or a mix of different colours and shapes. This gives you a lot of scope in terms of design.

The resin-aggregate mix is then laid onto a smooth base, such as tarmac or a specialised web base. So technically a resin-bound surface isn't a full driveway on its own because the base underneath it is creating the main bulk of the structure. You can think of it as more of a decorative surface. With that being said, resin bound driveways do provide their own contribution to the durability of the entire driveway.

A resin surface is porous, so provided that the base underneath is also porous, you can expect water and moisture to easily drain through the driveway. It is also UV resistant so isn't prone to discolouration, even without a sealer. Because of the nature of the mixture, it can also be contoured without the need for joints, which reduces the chances of weed growth through the resin-bound surface.

A resin-bonded driveway, on the other hand, is created by placing a layer of clear resin down over the smooth base and then scattering stones on top. Once the resin has cured, any loose stones are swept away. The resin-bonded material will look very similar to resin-bound but it is cheaper as well as less durable.

What causes a resin bound driveway to crack?

Resin-bound surfacing isn't prone to cracking on its own but forces that impact the resin surface can cause cracking, and most of these are avoidable if care is taken over the installation of your resin driveway.

Using the wrong substrate

Something completely smooth like tarmac or a specialist substrate is the best bet to ensure a stable base for a resin driveway. This is because these types of complete substrates won't move underneath the resin-bound driveway.

If you were to lay resin surfacing over something like block paving or crazy paving, however, you are likely to run into problems. The blocks will always shift and move even slightly, and this movement underneath your resin driveway can easily cause cracks in the surface.

Poorly mixed resin

Another reason why resin-bound driveways can crack is that the resin-aggregate mix isn't mixed together thoroughly. This can result in sections of the resin-bound surface that have clumps of stones and sections that are mainly resin. The difference in load and curing time between these sections can result in cracking.

The same issue can occur with resin-bonded driveways when the stones aren't scattered evenly.

Re-entrant cracking

Specialists at Guardian Resin say that reflective cracks can occur when there are sharp angles up against the resin surface, for example, sharp corners on a border. These create targeted and specific areas of stress on the resin-bound surfacing that can lead to cracks.

It is usually best to avoid encountering these angles in the first place but if that isn't possible, the resin can be reinforced in that area.

Reflective cracking

This is another cracking issue that is caused by the driveway surface underneath the resin. If it is made of something like concrete that has had joints installed to reduce the risk of the concrete itself cracking, this can actually lead to cracks in the resin.

These joints would have been installed to allow the concrete to have some movement, which will reduce cracking. But when a solid resin bound surface is laid on top, this movement underneath can lead it to crack.

There are two ways to deal with this issue. The first is to use a different base and the second is to use the same solution as in the concrete and create expansion joints in the resin itself.

High temperatures

Resin can be a difficult substance to work with and it is vitally important that it cures correctly. One of the most common problems is when the resin cures too quickly, and this is most often due to the temperature being too high when it is being laid. In these situations, the resin can become fully cured within a very short period of time which can cause cracks to occur.

Generally speaking, the operating temperature or ambient air temperature when laying a resin driveway should be between 10 and 35 degrees celsius. The reflective humidity should be between 30% and 85% and the surface temperature should be no more than three degrees Celsius on either side of the dew point of the measured air temperature and the relative humidity. A reliable weather app can help in deciding when the best day to attempt installation will be, and your installers will be able to measure precisely the temperatures when they arrive.

This, of course, creates a potential problem when installing this type of driveway in the summer. To avoid it, you can have your resin driveway installed in cooler months but if that isn't possible, your installers will likely choose to work early in the morning to avoid the high temperatures as much as possible and they will keep the resin mix in the shade to try and prevent it from overheating.

The bottom line

Cracks shouldn't be something you need to worry about with resin-bound driveways, as long as they are installed correctly. You can avoid most of the common issues related to cracked resin by ensuring that it is applied correctly, on the right surface, and at the right temperature.