Heritage NZ conservation architect Alison Dangerfield said the grant assisted in making the building watertight, crucial to the "stability and integrity of the building as a whole".
"The new roof is a very practical way of safeguarding this building for the future," she said.
Set on about 0.8 hectares and a few metres back from its former frontage to what is now the busy State Highway 2 between Waipawa and Hastings, it was built 161 years ago by local sawmiller Abraham Firth to serve the needs of families of timber workers and flax cutters living in what was a remote area, up to five days with horses and carts from the landing of supplies at Port Ahuriri.
In 1860 a road was constructed through Te Aute linking Napier with Waipukurau and a regular coach service was added soon afterwards.
The store became a coaching stop with stables, where horses could be changed, and passengers could enjoy refreshment.
Although construction of the Napier-Wellington railway in the early 1870s rendered the service obsolete, the building continued to function as a store, a focal point for the community best-known for Te Aute College, which had opened in 1854.
When the store closed in 1982 it was reported to be the longest continuing single business in a wooden building in New Zealand, in use for 124 years.
More recently it has functioned as a small museum and shop, as well as the private home as it was acquired by Keatley, ex-Auckland and Havelock North, and Kearney, more local and formerly a nurse in Waipukurau, and both keen gardeners.
The store sits within a beautiful garden setting, including mature, heritage trees also well over a century old, and a rose garden laid-out in 1900.
The couple, who made an instant decision to buy when friends put the site on the market, are delighted the fund has enabled them to upgrade the store's roof – which was starting to leak in places, but still has the perfectly-preserved sand-hewn timber shingles and the nails.
"When we bought the old store three years ago we knew she needed a new roof," said Keatley. "It's awesome to think that the interior and structure is now safe."
They plan to reopen a reinvented but currently original-condition storage room in the near future including public access to the rose garden.
"We would like to open a little shop, and share this with people," said Kearney. "It's one of the oldest building in New Zealand, and we definitely want to keep going. The next job is the floors."