Concrete Driveways on Sloping Sections

Plenty of Palmerston North properties are not flat. Aokautere, Summerhill and the other hill suburbs across the river are full of driveways that climb or drop steeply from the road. A concrete driveway is still the best surface for a sloping section, but it needs more planning than one on a flat section. Here is what changes and why.

Grip comes first

A smooth trowelled finish on a steep driveway is slippery in the wet, and in a Manawatū winter it is wet a lot of the time. On sloping driveways we use a finish with plenty of texture:

• Broom finish across the slope: the broom lines run across the driveway rather than down it, which gives tyres and shoes something to grip.
• Exposed aggregate: the stone texture holds well and looks good, which makes it a popular choice on new builds in the hill suburbs.
• Grit in the sealer: if you want a coloured or sealed finish on a slope, we add grit to the sealer so it does not turn into a slide.

Our driveway finishes guide compares all the options.

Water has to go somewhere

A sloping driveway collects rain from its whole length and sends it downhill fast. If the driveway runs down towards the house or garage, that water ends up at your garage door unless it is caught first. We plan the falls so water runs off the edges into the garden or a drain, and we fit channel drains across the driveway where they are needed, usually at the bottom before the garage. If the driveway runs down towards the road, we make sure the water leaves at the crossing and not across a neighbour's section.

Transitions stop cars scraping

The point where a steep driveway meets the road, the garage floor or a flat parking area is where cars scrape. A sharp change in grade will catch the underside of low cars and the tow bars on trailers and caravans. We build in gentler transitions at the top and bottom of the slope so the change happens over a few metres instead of all at once. Council rules also limit how steep a driveway can be and how it meets the road, so we check your site against them at the quote.

Pouring on a slope takes more work

Concrete wants to run downhill before it sets. On a steep driveway we:

• set stronger boxing and pour in sections, working up or down the slope
• use a mix that holds its shape on the grade
• often use a concrete pump when the truck cannot get close or safely park on the slope
• pin the reinforcing so it stays in the middle of the slab while we pour

That is the main reason a driveway on a sloping section costs more than the same area on a flat section. You can read about the other things that affect the price in our driveway cost breakdown.

Edges and retaining

On a section that falls away to one side, the edge of the driveway needs support so the base cannot wash out from underneath. Sometimes that means a thickened edge on the slab. Sometimes it means a small retaining wall or a kerb. We will tell you at the quote if your site needs one, and why.

Questions to ask any concreter about a sloping driveway

• What finish will you use, and how will it grip in the wet?
• Where will the water go, and do I need a channel drain?
• How will the driveway meet the road and the garage without scraping?
• Will you need a pump, and is it in the price?
• Does the edge need retaining or thickening?

If a quote does not answer those, it is probably missing something. We cover all of them in our written quote. Find out more about our concrete driveways in Palmerston North, or get in touch for a free on-site quote.

More driveway guides

• Concrete driveway finishes compared
• Vehicle crossings in Palmerston North
• Concrete driveways in Palmerston North