PROPER RAMP FOUNDATION IS ONE OF THE KEY ELEMENTS OF BUILDING A LONG LASTING RAMP.
We strongly recommend building your ramp on an elevated foundation. This will allow for any rain water to flow freely underneath the ramp and will increase airflow to help keep your ramp structure dry and prevent rotting/decay.
Levelling your ramp - lengthwise the ramp needs to be built as level as possible to the naked eye. Widthwise we recommend a 1 degree fall to allow any rain water to run off. You can build on dirt, gravel, grass, concrete, asphalt etc.
Best types of ramp foundations
This is the easiest solution if you have an existing concrete pad to work with. Make sure that there's no water pooling before installing - we like to elevate the ramps using offcuts of our composite ramp surface. This way any water can flow freely and not get trapped underneath the ramp.
Concrete pavers are cheap and easily acquired from Bunnings. We recommend 300x300x40mm as the minimum size. A 3FT high halfpipe will require around 20-30 pavers depending if you need to stack more than one to level your foundation. For enough support we place them every 120-180cm apart.
H3 TREATED SUBFRAME
For areas that have a significant slope a subframe needs to be built. This is a good solution but will add extra cost to your ramp build. We use 190x45mm H3/H4 pressure treated timber for the subframe and either concrete the supporting legs or place them on concrete pavers.