Demolished buildings lead new existence

17:34, Dec 05 2012
Recycling demolished buildings

Tall buildings demolished in Christchurch have been recycled as fertiliser, farm bridges and mulch, while $200,000 of recovered office equipment has been donated to local schools.

The recycling rate for large buildings such as the PWC tower, Holiday Inn, Farmer's car park building and Clarendon Tower is at least 90 per cent, according to demolition firms.

Concrete, metal, plasterboard, furniture and untreated timber are recovered from buildings during demolition.

About 200 concrete floor plates recovered from Clarendon Tower are being used on South Island farms as bridges for irrigation channels. The slabs have also been used in the Gap Filler pallet arena being constructed on the former Crowne Plaza site.

Smith Cranes demolition co-ordinator Hamish Wright said the slabs were being used on farms as far afield as Invercargill.

"A farmer from Ashburton called me. He had seen a building coming down and asked if we had any concrete beams. Soon after that, the old bush telegraph kicked into gear and now we're getting about five calls a day.


"It has been good, because otherwise we would be burning diesel to chomp it up and use it as hard fill."

Furniture and office equipment that owners do not want to recover have also found a new home.

Smith Cranes has donated recovered computers to schools through the Christchurch Rotary Club, with about 30 going to schools in Solomon Islands.

Demolition firm Nikau has been working with an education publisher to donate office equipment recovered from doomed buildings to Christchurch schools.

Anthony Richards, of education publisher Tomorrow's Schools Today, has co-ordinated the donations with Helina Stil, of Nikau.

"This is all stuff that has been written off and sitting in a building for a year or so. Anything that the schools don't have to purchase has got to be a good thing," he said.

Opawa School principal Grant Stedman said the donated furniture was helpful. The school had received 20 chairs for its meeting room and whiteboards for the classrooms.

"We didn't have the money to purchase new chairs so it was really wonderful for us. All we had to do was clean them. To get something for free is a bonus. It would have cost us a tidy sum if we had purchased them, probably about $4000."

Stil said that in some buildings slated for demolition there were "floors and floors of office equipment" that the owner did not want to claim.

"I don't see why it should go to landfill when it can benefit schools in the community. It helps to reduce our costs by cutting the amount we send to landfill, but the main thing for us is being able to help out the community," she said.

In most demolitions, concrete is ground up and used to fill in the basements of demolished buildings or as fill for the Lyttelton Port land reclamation project. Metals such as aluminium, steel and copper are recovered and sold to scrap merchants, who sell it worldwide.

Untreated timber can be shredded into mulch for gardening, while plasterboard can be processed into gypsum and used in fertiliser.

The demolition of the Farmer's car park building, Clarendon Tower, PWC tower and Holiday Inn has recycled about 60,000 tonnes of concrete and about 3000 tonnes of steel. About 10 tonnes of copper was reclaimed from the roof of the Holiday Inn.

The Press