Strengthening work underway at Old St Paul's

29/04/2019

Historic Old St Paul’s in Wellington has been saved once – now it’s being saved again as work begins this month on strengthening, upgrading and restoring the Heritage New Zealand cared for property.

The national treasure closes its doors on Friday 3 May in preparation for the #ForeverOSP project that will involve internal structural strengthening, external work to repair cracking and painting, and fire and electrical upgrades.  This work is necessary after Old St Paul’s was impacted by the Kaikoura earthquake in November 2016.

Old St Paul’s is expected to be closed for between eight to 10 months as the project, estimated in excess of $2 million, is completed.  It will be the first time it has closed for any significant length of time since the late 1960s when heritage advocates saved it from demolition. 

For structural engineer Alistair Cattanach, Director of Dunning Thornton consultants, the #ForeverOSP project is a real challenge but one he is looking forward to.  Alistair was Director in charge of the major seismic retrofit and refurbishment of the Category 1 listed Old Public Trust building in Wellington and, was Peer Reviewer of the strengthening of St Mary’s of the Angels, also in Wellington.

"The positives with Old St Paul’s are that it’s very flexible, it’s very resilient.  We saw that in the way it went through the earthquakes," says Alistair.

"The negatives are because of the way it’s constructed – everything is mortise and tenoned together (a mortise and tenon joint connects two pieces of wood, mainly when they are at right angles) – there’s nothing that holds those joints shut.  So what’s happened in the earthquakes is that it has oscillated backwards and forwards and those mortise and tenons have started to dislocate and the church has actually gotten up to 150mm wider in places.

"The strengthening we are looking at doing is to very carefully tie those joints together so they will no longer dislocate, and as part of that were going to look at correcting the widening of the building."

There will be three main phases to the strengthening, says Alistair.  The first phase will involve tying the framing with imported metal screws “in very careful positions”, followed by adding strength with clamping rods and metalwork to the building.  This will also include trying to straighten some of the walls.  The final part involves concreting work on the foundations.

"This building already has a lot of strength because it’s timber.  Each piece has a lot of strength in itself and all we’re doing is knitting that together.  It’s only the connections that we need to augment.  So rather than replacement we’re able to keep far more of the heritage fabric and just augment what is already there which is a great result from a heritage point of view."

When the #ForeverOSP project is complete it will bring the building’s current seismic rating of above 34 percent to 90+ percent.

Fundraising for the project continues, with our online campaign and the tap-and-go 'donation station' at Old St Paul’s a great way to show support.

A 'tap-and-go' facility will remain on site during the strengthening work.  

"Heritage New Zealand is investigating creating a viewing space so the public can come and watch the project progress," says Heritage New Zealand’s Manager Asset Funding, Brendon Veale.

"While project costs will be covered by Heritage New Zealand, with the remainder from key donors, in particular the Friends of Old St Paul’s, New Zealand Lottery Grants Board and Stout Trust, donations from the public and supporters are very welcome and much appreciated.

"Old St Paul’s is owned by all New Zealanders – it belongs to the nation.  Heritage New Zealand is the guardian of this fantastic, all-inclusive, national treasure."

If you would like to contribute to help ensure the future of Old St Paul’s is forever, please visit heritage.org.nz/donate

For more information:

Paulette Wallace
Manager Heritage Assets Central
Heritage New Zealand Pouhere Taonga
tel: 04 494 8048 or 027 298 4359
email: pwallace@heritage.org.nz