Ballast Base for Driveways

Do I really need a ballast base under my driveway?

Yes you really do need a ballast base under your driveway. Without it the ground underneath will shift and settle or wash out over time and that is when you get cracks or dips showing up. The ballast spreads the weight of the drive, keeps everything stable and helps water drain through instead of sitting underneath the slab or blocks. It might seem like a job you can skip to save time or money but the base is what carries the whole lot. A good solid layer of compacted ballast is what stops your driveway from giving you grief a few months down the line.

Will the base help stop my driveway from sinking or cracking?

Yes the base is what keeps your driveway from sinking or cracking and it is one of the most important parts of the whole job. It spreads the weight of cars and whatever else goes on top so the concrete or blocks are not left trying to hold everything up on their own. If the base is deep enough compacted properly and built on firm ground it gives you a strong foundation that will last for years.

When the base is too shallow or loose the ground underneath can move around especially after heavy rain or cold weather. That is when cracks start creeping in or you notice dips forming where the weight has pushed down. Even if the surface looks perfect at first it will not stay that way if the base is not doing its job.

A good base made from the right material and properly compacted keeps everything stable stops movement and helps with drainage too. It is not the part anyone sees but it is what holds the whole driveway together.

How is the ballast compacted before the concrete goes down?

• ✔Ballast is compacted in layers to ensure a solid, stable base that won't shift later.
• ✔The first few inches of ballast are spread evenly, then compacted with a plate compactor until firm.
• ✔Deeper bases are built gradually—about four inches at a time—compacting each layer before adding more.
• ✔Skipping or poorly done compaction can lead to settling, which causes cracks and dips in the concrete later.
• ✔A properly compacted surface should feel firm underfoot, with no soft spots or shifting.
• ✔Edges and corners must be compacted as thoroughly as the center to prevent future shifting.
• ✔In soft or wet ground conditions, a geotextile fabric may be used underneath to prevent the ballast from sinking.
• ✔The goal is to lock everything in place, creating a stable base for the concrete that won’t move over time.

How do I know if the base has been compacted properly?

You will know the base has been compacted properly when it feels firm underfoot and there is no give when you walk across it. It should feel solid like packed earth not loose or springy. If you can dig your heel into it or see the ballast shifting around it needs more work.

A properly compacted base will hold its shape and stay level across the whole area. There should be no dips or soft patches or spots that feel different to the rest. Run a straight edge or a bit of timber across the top and check for any gaps underneath. That will show if the surface is even and firm all the way through.

Also the compactor should leave faint marks but not deep ruts. If it is bouncing or riding on top without biting into the surface it might be too dry or not layered right. Taking your time and doing it in stages is what makes the difference.