Wood chip driveway - a success story.

I'm putting this here for those that come after us and are looking for a first hand account from someone who feels this has been successful for us.

When in the ideation phase of a new project I traipse all across the internet looking to pick up tips, tricks, do's and don'ts.  It's rare that I don't find what I'm looking for but this project was one of those times.  When we bought our land it was just a 1 acre paddock, owned by an acquaintance (now friend) as a place to escape occasionally, grazed by horses and donkeys owned by a local organic, rare breeds farmer.  It was steep hill and the driveway went all of three metres from the road to the gate and then ended.  We bought it in the middle of summer so our BMW had no problem getting up at the time.  That changed with the first decent rain.

We generally try to avoid concrete, and gravel (metal as its called here) wasn't high on our priority list either.  I got to wondering about wood chip.  I scoured the internet and only found two or three examples of people who tried it.  None of their scenarios matched ours well enough to be confident, but each said they loved it and it performed better than expected.  Then there were plenty of comments from people who hadn't tried it and who were adamant that a wood chip drive would never work at all, or only in dry climates, or only in dry climates with a flat section.

We live on a relatively steep acre - it's probably 15 metres climb from the roadside to our bus at the back of the property, and we get 1.8 - 2 metres of rain per year on average.  We got just shy of 10 inches of rain last week alone.  We do get a few frosts a year, but so far no snow and no long-term freezes - just to round out the picture as, again, I'm leaving this here for anyone who comes in the future and wants to try and compare climactic and geographic apples to apples.  Our soil is amorphous clay.

I don't know what sold me on it, but eventually I figured we should try it and talked to my husband about it.  I guess I figured no matter what kind of loose fill drive we put in we'd need to do the same work up front and if the wood chip didn't work out we could always use it around the garden.  Thankfully, he's generally got more faith in me than I do.

We borrowed a friend's rotary hoe and dug two channels about car tyre width apart and 40cm deep from the front gate, winding up the hill all the way to the flattened area where we will one day build our house.  That was days of labour in itself - just hauling the clay and depositing it somewhere.  I don't even remember where it went - maybe around the pond?

I think we must have had the wood chip delivered by the time we finished so we spent another day moving 30 cubes of wood chip into the tracks that we cut, and driving the car back and forth to compact it.

Things we had to fix over the long term (many of which I reckon we would have had to fix if we put in a gravel drive, by the way):

- The camber of the turn going up the hill was wrong, fixing that made getting up the steeper part of the hill much easier.

- The turn up the hill was too sharp, and the drive around that corner was too narrow.  Widening that out helped tremendously.

- I listened to a few people who spoke with confidence and authority when they told me that I had to put in perforated drainage pipe and gravel for the two places I planned drainage to run under the road and into the pond.  The gravel gummed up the drainage pipe in short order and, obviously, that caused much of the system that was our driveway to bog up and get difficult.

- We had nowhere near enough drainage.  Common sense makes so much sense when you mess things up the first time.  Ultimately with a wood chip drive the key to making them work is keeping as much water off of them as possible and helping them to shed what water they have.  We were simply too green at first and hadn't experienced the amount of rain we get out here, so got that wrong from the start.  To fix this we dug trenches running the whole length of the drive on one side, and most of the way down on the other (because of other obstructions), then picked some strategic spots in the driveway, pulled up the chip, dug trenches across the drive to connect to the two main trenches then filled it all in with chip.  In the near 10 inches of rain we got last week there was no evidence of runoff.

- We planned the drive based on the tyre width from the BMW.  Shortly after we moved here we realised it was an awful car for our situation and would always be problematic.  I also needed a 4WD for work so I bought an SUV whose tyres were much farther apart and tended to bring up clay that would coat the chip that would make it impassable for the BMW.  We ended up widening the tracks and then spreading enough chip to have a solid drive where originally we were hoping for just the two tyre tracks.  In time the earth is fixing this for us and starting to grow things down the middle where we don't drive.  We also recently bought a Toyota Aqua (I think it's the Prius C in the US) because my husband is back and forth to town *SO MUCH* for work the petrol costs were killing us.  The Aqua literally pays for itself *AND* I guess since it's so much lighter and front wheel drive it's never hesitated to get up the drive.

- The soil was still pretty barren from the earthworks that we did so every time I had to drive somewhere that wasn't on the tracks when it was raining I'd coat my tyres in wet clay which would get deposited onto the wood chip and make it impassable for the BMW.  We could have brought in some hay or other organic material to cover the clay while things got established but we just let time handle it instead.  It has done and this is no longer a problem.

Ongoing downsides:

1 - We still have one spot that's a little boggy.  It's a patch no more than 1 metre long and 30cm wide.  I reckon there's blue papa clay that got deposited there from when the clay dug from the pond got used to create the path for the drive.  It doesn't stop our ingress or egress.  I suspect once a year I'll have to dig out that small section, discard the saturated clay and add more chip but I also reckon it won't take too much more effort to get that fixed permanently.

2 - We have to top up the chip every year.  We knew that when we decided to do it.  Wood chip is light, pretty cheap, and easy to work with.  It takes a couple of hours once a year.  Also, we'll soon be in a place where we can start collecting windfall and other downed trees from some of our friendly, generous farmer neighbours and start chipping our own local wood.

At this time we've probably put something like 70 cubes down and spent something along the lines of 2,800 NZD, including a parking pad for two vehicles (we ran out of chip before we could get the third space done).  Right now, I suspect we'll add 10 cubes/year and, in exchange, maintain a driveway whose ethics and aesthetic are more in line with what we want, and that must have a relatively high albedo effect as it takes just a couple days of sun before it's bleached pretty white.  It's also just pretty darn neat.

There's certainly a question of how much nitrogen it's leaching from the soil as it breaks down.  I have no idea how to quantify that.  All I know is that, at this point, the vegetation that grows next to the drive doesn't show any signs of nitrogen deficiency so :::shrug::: we'll find out.

In the end, I love our drive way.  I'd do it again in a heartbeat, even if I had to make all the same, frustrating mistakes over again.

The end.

Looks great! Thanks for sharing a detailed account of what you did and how it's going.

We've got an informal driveway around two sides of our property that leads to the corner where a friend lives in a caravan. Not only does he need access (in an Aqua, coincidentally) but once a year we need to get a ute in to take the caravan to the dealer for its annual service and warrant of fitness. Our land is just about dead flat, and although the soil drains readily we can also get ridiculous wet spells like the past week, and the whole winter for that matter. When that happens things turn to mush in a heartbeat if you try to drive over them.

I didn't want to bring in truckloads of metal either and ended up having several cubes of stump grindings spread over the low spots. The grindings are about equal parts shredded wood and soil, and have made a big difference both in bringing up the grade and spreading the load from the car tyres. They slowly turn into topsoil and I top up the places that need it from time to time with chips and bark pieces. So far so good and the materials were free from my arborist mate, who has no market for the grindings so brings them here if I want them.

I'm pleased the stump grinding are working out for you.  And, truly, I'm thankful for the response.  I'm just hoping that someone in the future comes across this post when they're looking at alternative ways to lay a driveway.  It would have saved me weeks of agonising over it if I could just have read a first hand account and known I wasn't throwing away money on a pipe dream.

Three quarters of what I've done to/for my land has been because someone offered us free resources and I won't/couldn't say no.  The tonnes of hay, silage, manure, and trailers full of wool have made this property what it is and it was all on the kindness of neighbours - some of which were strangers at the time.

Also though, no jokes about the rain.  I'm over it, but I feel like I need to say that in a whisper since it's going to stop soon and then we'll be thrust into the middle of another hot, dry summer.

Thanks for sharing.
I imagine the road turns and go uphill ? That is hard to see on the picture.
I have a similar road were i wonder what to do with that road when we move up hil.
But maybe woodchips is the answer thanks

Yep, it does.  You can just see the top of my black SUV in the picture that's actually parked on the hill so you get a bit of an understanding what the slope is like.

Thank you for posting.  I've been wondering about woodchip driveways for a while.  

The soil around my chip pile is as soft as can be.  I wouldn’t recommend chips for a driveway. Maybe a charcoal (for the fines)/gravel blend if you are trying to reduce the carbon emissions of building a driveway.