Wellington Scoop

Saving money with sticky chips


by Benoit Pette
Sometimes, presents come from unexpected people. Sometimes, you would rather do without those presents. Take Totara Road in Miramar: it seemed fine, with a nice asphalt covering, but it needed to be resealed because accountants said it had exceeded its lifecycle. So over the summer holidays, the Wellington City Council resealed three sections of it. But instead of resealing using asphalt, the council went with “chip seal”.

What is chip seal (or cheap seal)? It’s a coarse, stony, sticky gum, that creates roads only one level above a gravel road, which leaves stones running freely for months, and is significantly (by three-folds) noisier than asphalt, not only for road users, but more importantly for residents living next to it.

Since it wasn’t the first time we’d noticed a road had been administratively sabotaged in such a fashion, we decided to contact the council to enquire why a road that seemed fine had been punished like this. Here was its response:

Totara Road was sealed a couple of weeks ago. The previous seal on Totara Road had exceeded its life cycle and was showing signs of failure. One of the reasons why we chip seal is that it gives the pavement a good waterproof layer which asphalt fails to provide. The other reason is asphalt way expensive than chipseal. We are required to reseal as much of our network as possible every year with the budget we have available. Choosing asphalt because it provides a smooth surface is really not a feasible option. Chipseal was the best option for the road. All road works are complete on the road but may require some sweeping. Contractors are responsible for picking up loose chips from channel, driveway or footpath after sealing. You can always raise a query about loose chips (if any) lying around and I can send the contractor to pick it up.

It must be said our enquiry contained concerns about the effect of the stones on cars (some even made it into our house!), about the extra noise, and overall, a certain unease that our city roads would, ultimately, all be converted to sub-standard and overall lower quality.

It made us wonder if it was a good strategy to maintain our shared asset with band-aids.

After all, we’ve seen recently what under-funding does to, say, waste water pipes over time.

Why do we run after white elephants (some call them vanity projects) when we can’t even do the basics right? Is that an appropriate strategy when our city is growing? Or to set a budget knowing the next generation will end up with a more expensive bill?


  1. Paul, 14. February 2020, 10:27

    We had our road cheap sealed about 5 years ago. It was more than 3 years before we stopped continually having to sweep stones off our drive.
    The condition of the road is now (and has been for at least a year) much worse than the asphalt they replaced – which had lasted at least 7 years. I would rather have the crap road we have now than let them re chip it again! I do not want another 3 years of a sticky mess with stones everywhere.

  2. michael, 14. February 2020, 11:07

    It’s called false economy! Cheap and nasty where “need to have” infrastruture is concerned, and well over the top for possibly “nice to have” vanity projects. No doubt we can expect a lot more of this as pipes continue to burst and roads are given a quick fix, while vanity projects gobble up hundreds of millions of ratepayers’ money.

  3. Ben, 16. February 2020, 21:19

    Heck you’re right on that. Road resealing is done to such a poor standard these days. Until recently I’d never encountered corrugations in a newly cheap-chip sealed road. Two local areas were relaid just like that – the WCC took a couple of years to fill in the dips of one section with strips of asphalt. Box Hill (right outside Peter Dunne’s place) was a rollercoaster. Time and time again it got dug out and relaid. It has just been done again in fact… bouncy bouncy.

    Chip seal that gets laid poorly only to come straight up again. There is no apparent oversight and the contractors know they’ll have more guaranteed work in a year or two as the original work fails. It really is time our rates started getting used for decent quality work. And as for the three waters – there’s been decades of finger-pointing and avoidance. It’s all coming to a head now.

  4. Alf the Aspirational Apteryx, 17. February 2020, 8:26

    Our suburban road was resealed with chip last October. It’s a total mess. Much of the tar has never set and the loose chip gets everywhere. Cars passing along it make a thumping sound as the chip clumps to their tires. The chips and tar stick to shoes and ruin them. There have been complaints to the Council but nothing happens.

  5. Mark Shanks, 17. February 2020, 8:32

    The Wainuiomata Hill road has just been chip sealed. Thousands of stones have ended up on the new shared pathway making it difficult for walkers and cyclists. I wonder how many drivers have chipped windscreens as well.

  6. William, 17. February 2020, 16:59

    My observation while living at our address in suburban Wellington for over 30 years is that the resurfacing is done on a repeating cycle.
    Smooth asphalt is in place for maybe up to 10 years, and is then overlaid with coarse chips. After about two years this is overlaid with fine chips, and then maybe two years later this is resealed with asphalt again, which then lasts another 10 years. I’ve assumed this is done to maintain structural strength and waterproofing using chip, but long life using asphalt. I would also expect the exact treatment to vary for different roads depending on the amount of traffic.
    I’m not a civil engineer, but I’m not convinced whoever wrote the reply from WCC is either.

  7. Roadie, 19. February 2020, 17:23

    The decision on the type of seal is made by the council’s Transport Assets Team.
    What do we know about this team?
    1. Their decision making needs to be questioned.
    2. They don’t monitor completed work.
    3. They have no regard to the impact on the residents.
    One example, and I know there are many, is Helston Road in Paparangi. Helston Road is a main road & bus route with many bends linking Newlands & Johnsonville.
    The residents of Helston Road voiced their concerns regarding the chipsealing of the road in February 2019. Our concerns were dismissed. The road was sealed with, and I quote, ‘a Polymer Modified bituminous binder and chip which is stronger than the normal material used for chip sealing other streets in the vicinity.’ They told us it would seal the substructure. However, the bottom line reason for the use of this material was the cost.

    This extremely noisy & messy seal lasted less than 6 months. A year later a section of it has been completely stripped off and bitumen put down.

    Thank you to Councillor Dr. Jenny Condie for following up on Helston Road. Jenny’s involvement resulted in some of the road being resealed as it should have been done in the first place.

  8. Dave B, 20. February 2020, 21:57

    Some years ago they chip-sealed some of the bends on the Ngaio Gorge road. Within months the stones got completely scuffed off where most of the tyres track, leaving ruts of exposed bitumen. It wasn’t long before they had to re-do them all properly – with asphalt-concrete.

    There are some roads where you may get away with chip-seal – like straight, flat roads, certainly not the Ngaio Gorge. And if it is to be used on suburban streets it must be on low-speed roads only, to keep the noise and mess down.

    They have just-now resealed the bend at the very top of Ngaio Gorge. Happy-to-say they have done it right first-time, using asphalt-concrete.

    “Bitterness of poor-quality remains, long after sweetness of low-price is forgotten”.

  9. Chris Calvi-Freeman, 20. February 2020, 22:37

    I’m no fan of chip seal, and had occasion to query its use on many occasions when I was on the city council. I accepted the explanation that it was effectively a “mid life range extender” for asphalt roads: the chip seal prevents water ingress that would otherwise result in potholes, then a few years later the road is excavated and asphalt sealed again. That’s all well & good if the chip seal is applied correctly – several times a couple of summers ago it wasn’t and there were many justified complaints of “tar” and sticky stones being walked into cars and houses.

    Chip is also very noisy, both for car users and nearby residents, and the coarser chip used on busy roads is unsuitable for cycling on – something that must be borne in mind if the city wants to encourage more people to commute by bike.

  10. steve doole, 24. February 2020, 6:46

    There are many factors in choosing what to resurface a road with.
    Chris is correct. If the existing surface is cracked or fractured, then adding a new layer of sealant can be a good choice when most of the structure of the roadway has not been damaged.
    Where fractures show, the structure of the roadway is often examined, say 30cm down.
    Fractures occur due to shear forces where heavy vehicles turn, such as on bends in Ngaio Gorge.

    The strength of bitumen/ashhfelt/tarmac/blacktop/macadam can be expressed by its ‘stone’ content. Again strong road surfaces are needed where heavy vehicles pass often.
    I agree – the use of Stone chips is not great for cyclists, but stones impacted into the road surface can strengthen the road before a smooth top layer is added two or three months later.
    Timely sweeping of loose stone is helpful meantime, and explanation by council could be better.

  11. Stefan, 25. February 2020, 0:19

    I’ve seen a fog seal applied after the chip seal is swept in the U.S., seemed to solve the loose stone issues.

  12. Benoit, 26. February 2020, 17:34

    WgtnCC. Totara Road still throws stones and chips en masse on to the cars when driving on it, even at very low speed. Has it been swept? Can you send the contractor to sweep one more time please? Thanks.