The library closed last June to undergo seismic strengthening. Photo: RNZ / Samantha Gee
Earthquake strengthening work on Nelson's main library could cost almost a million dollars more than planned after structural damage was found in its roof.
Contractors found four damaged trusses in the oldest section of the library, while it was undergoing seismic strengthening.
Nelson Mayor Nick Smith said the discovery was disappointing as it set back the full reopening by seven months and added $940,000 to the cost when the project was previously on schedule and on budget.
The problem stemmed from when heated ceiling tiles and skylights were added to the trusses in 1989, overloading them, he said.
"The new work involves installing 17 steel columns, with concrete foundations and steel beams between them, in this oldest public section of the library to underpin and address the under-capacity of the trusses. Finding this flaw with the trusses has also resolved the question of the cause of roof leaks that now enables a more comprehensive fix of that issue."
The Nelson City Council made the decision to close the library last June, after it was found that some ceiling tiles were heavier than expected and posed an earthquake risk.
A small pop-up library opened last July after initial strengthening work at a cost of $200,000. The second stage of which was currently underway with a budgeted cost of $1.4 million.
Despite the delay, a further section of the library was able to open on 26 July and will double the area available for public use.
Nelson City Council chief executive Nigel Philpott said it would be the fourth change to the library space in just over a year for staff, who were looking forward to a library that more closely resembles the original area.
"We've gone from complete closure to a small, successful pop up, to a larger space and now we are getting back most of the library space and amenities that we know our community has been missing."
A request for a further $940,000 to repair the additional damage will be made to council next month.
If approved, it will bring the total cost of the Elma Turner Library earthquake strengthening project to $2.7m.
