After two cases of boot soles peeling away without warning, Frances Daroux wants more to be done to ensure tramping boots are fit for purpose.

In the wilderness, you depend heavily on your gear. It has to be reliable, but what happens when your most important piece of kit – your footwear – fails?

Just such a scenario befell me and a person in my tramping circle in the past year. Both of us had the misfortune to see the soles of our boots delaminate – simply peel away – without warning.

My boots, a three-season flexible-midsole model, were around eight years old, used on a couple of trips a year (i.e. infrequently), were cleaned and oiled before storing away, worn to cross rivers but always dried naturally afterwards.

While walking the track to Mueller Hut, I suddenly fell heavily and dislocated my shoulder. I could not understand why I fell. But once we started walking again, I realised the soles on both of my boots had come loose from the middle to the heel. This is what had tripped me up.

I flapped my way to the hut using all my strapping tape to tie the boots together. By the end of the tramp the following day, I had worn through the tape and the soles were only attached at the toes making walking extremely challenging. I was lucky that my shoulder popped back into its socket and anti-inflammatories and painkillers eased the pain so that we could continue our tramp.

My friend had a similar experience, but her three-season boots were brand new. That didn’t stop them falling apart during a four-day tramp in Nelson Lakes National Park. She glued them back together, but this remedy lasted just a few months before the soles fell off on the third day of a 10-day tramp.

I contacted the local distributor of my boots to find out what was going on. They said the delamination was due to hydrolysis – a spontaneous chemical reaction resulting in natural deterioration of polyurethane (PU) compounds. This happens if you rarely use your boots, even if new or unworn, and the soles become hard and dry. It occurs more frequently in a humid microclimate like New Zealand or by using the boots in wet places. Apparently, this can happen to any brand which uses PU compounds. Even new boots can be ‘old’ if a retailer has a slow turnover.

The distributor recommended wearing boots on a regular basis to keep the soles “active”, to store them in a dry place, keep them clean, treat with a maintenance kit, and not to dry them near a heat source. They also said it is preferable to give the boots a dry wash, rather than a wet wash from which they might not dry properly.

I contacted outdoor store Living Simply in Newmarket for more information. Managing director Ben Sinclair says delamination is a counterintuitive issue that customers can struggle to wrap their heads around, as boots used just a couple of times are more likely to be affected than frequently used boots.

The problem isn’t brand specific and tends to occur on high-end boots, which use polyurethane in their construction.

“Polyurethane responds to being walked in, and the pumping action of walking puts pressure into the midsole which squeezes out humidity and moisture, and keeps the bond fresh,” he says.

“The worst thing you can do is get a new pair of boots, wear them on a walk, and then store them in a garden shed for years.

“The solution to slow this biodegradation is to use your boots frequently, even if it’s just a short walk, and store them in a warm dry environment.”

If you’re concerned your boots may be affected, scratch the midsole before you set off tramping – if it comes off under your nail, you are probably looking at needing a new pair of boots.

But because soles can delaminate at any time – even if the boot has hardly been used and the user follows the advice of retailers and distributors – it got me thinking that tramping boots should have the equivalent of a ‘best (sold) before’ date stamped on them so retailers and customers can make an informed decision about what they are buying and selling.

I also question if boots that are supposed to be rugged and durable are actually fit for purpose if they so easily fall apart.

I’d also like to see customers warned when purchasing their new boots about the possibility of sole delamination and informed of the precautions to minimise the risk of it happening.

Even then, I’d advise everyone to carry sturdy tape, cord, an appropriate glue or back-up footwear just in case.

How often do soles just fall off?
We asked two of our top contributors who are amongst New Zealand’s most experienced trampers if they have had any problems with soles falling off.

Here’s what they had to say:

• Pat Barrett: “Yes it’s reasonably common on cheaper boots that are used in too rough terrain. It happened to a mate of mine last year on an off-track day trip. The boots just weren’t made to a really robust standard for the rough terrain we were in.”
• Shaun Barnett: “Yes, it’s quite common now that soles are only glued on, not stitched and glued, as they more commonly used to be (some more expensive brands still do). I’ve had plenty of boots with soles that have come off. You can get them re-glued, but they usually don’t last. I carry some strong strapping tape and have used this on occasions to make sure of a temporary repair.”

UPDATE: We were inundated with reader tales of boot decay. You can read a selection in the story ‘Flapping hell‘ published in the August 2019 issue.