Using a concrete or sand & concrete dry mix base is key for your garden patio or driveway to last the test of time. If you are going to use a sharp sand base without concrete then be prepared for the consequences. Sand moves over time and causes many issues such as dipping and lots of movement.
Some landscapers use sand and concrete mix that will set after your patio has been laid, this will suffice for gardens and pathways. But, if your planning on parking your car on your driveway without a concrete base then it will not last 6-months.
Concrete Base For Driveways
For a driveway that is receiving a lot of weight or constant traffic, you must use a hardcore base and at least 4 inches of concrete to prevent it from cracking. The ratio should be 3 parts hardcore to 1 cement.
- 3,2, 1 ratio of sand/gravel and cement
- 4 inches of concrete
- use steel mesh for extra strength
- Hardcore such as broken bricks, rocks or scalpings
- 3 inches of hardcore
If you follow this base for a driveway then you will not experience cracks or dips. If you are paving or slabbing this base then be sure to cover the bed of your slabs. DO NOT just bed the corners and centre because if you park a car on these slabs they might crack and break.
Concrete Base For Garden Patios and Pathways
For general patios and pathways, you can use a dry mix, but this will not be as strong as a solid concrete base. If you are “building to stay” as we call it in the trade then we would advise you to lay a concrete base 3″ and bed your slabs on top because it will last 20, 30 or 40 years.
A dry sand and cement base works well but will not last as long! It might last 5/10 years before it moves and deteriorates. Once the rain starts to wash through and the seasons start to change you will notice dips and movement! For best results:
- lay hardcore 2″ and a concrete base 3″
- Bed slabs on top with a strong sand and cement mixture
- Use steel mesh for extra strength
If you are crazy paving then you can still use a concrete base and add the dry sand and cement on top. Most contractors or landscapers will lay scalpings as hardcore and dry mix sand and cement for a bedding base as they lay the blocks.
This method looks great for a few years but will deteriorate/dip over a few years when exposed to the elements. All you have to do is look around at older driveways and patios in your local area.