That is because when resident Jan Howden opened the store in a former rural supply shop, it overflowed.
First into the yard, then a neighbouring house, then a shed and the town’s former post office.
Jan is now calling time on the business which has been her life for more than 20 years.
She had always planned to retire when she was 80, but has now passed that milestone.
Motivated by a love of all things old, interesting and unusual, Jan sourced stock from near and far - estates, auctions, people down-sizing and businesses closing.
Seekers of curios and vintage coming from across Canterbury and further afield have found much to delight on the shelves and hangers - fur coats, Crown Lynn and other china, kitchen equipment including a mincer, buttons from a military uniform, doilies like their nan made, machinery parts (including for a DC3 aircraft), a book on the etiquette of nose hygiene.
Once Jan was even asked for a coffin, which she did not have.
‘‘I once was offered a new coffin, but turned it down as it just didn't feel right,’’ she said.
Many of her customers came to Mayfield for the express purpose of visiting the store, which opened three days a week, Friday to Sunday.
‘‘One day I had a phone call from Holland. The caller asked how long it would take to get to Mayfield, ‘We have seen photos of your stock and you have what we want’.’’
Their three-day visit to New Zealand was for the purpose of visiting Overflow. ‘‘The other businesses in Mayfield said their tills rang better when we were open,’’ Overflow owner Jan Howden said.
Jan was well known for being fair in her pricing, something she said she needed to offer in a small town.
Customers also appreciated her experience and knowledge, something which came from more than 40 years experience in the wheeling and dealing trade.
Her foray into buying and selling began with markets and swap meets. She originally purchased the Mayfield premises as a place to store her stock.
‘‘People would contact me saying we can see this item in your storage and we want to buy it. That’s when I decided to open the shop,’’ Jan said.
Over her many years of being in the secondhand trade, Jan had heard some sad stories.
For some it had been hard to part with goods they had offered to sell, as it could be the last link with a loved one.
‘‘I have had children and other family members come in wanting, or demanding items from their families back, or details of who I had sold the item to. Often if the child was present when I was buying something I thought they might want, I asked them before I bought it,’’ she said.
She said men would bring in their mother's or wife's clothing wanting to share the garment's history.
‘‘When you buy off a man he tells you when she wore it and where she wore it. You buy off a woman, often she wants to get rid of it,’’ Jan said.
‘‘I’ve learnt to be careful with people’s emotions, to graciously take things and not offend them by my saying what I think of some of the items.’’
She had had many happy times in the business, and met many wonderful people.
‘‘I am thankful to all my customers, the people I have met through my buying and selling,’’ Jan said.
Come the end of April the stock will have been cleaned out as Jan has sold the buildings and is closing the doors. Some of the unsold goods will be going to charity.
The one thing she would miss most once the keys were handed over, was the people.
‘‘I have made lots of friends, many who have been calling in to say goodbye and giving me a hug,’’ she said.
A part of the business she had enjoyed was helping the community and other groups. An example was material, buttons and zips going to women prisoners for a sewing programme.
She has much to look forward to as retirement promises more time for herself and husband Peter.
The couple’s farm has sold and its many storage sheds are being cleaned out as the they prepare to move to Ashburton in the future. And today they are celebrating 60 years of marriage.
