RESTORATION works at York's historic Walmgate Bar have been hit by delays, due to the discovery of more severe rot and structural problems.

The medieval gateway could be at risk of collapse unless vital new work is carried out.

A horizontal timber lying across the two columns on the inside of the bar has begun tilting and must be stabilised, it has emerged. Additional rot has also come to light, along with mistakes and shortcuts by previous restoration teams - including the use of basic domestic skirting board as part of the rendering on the top of the bar.

John Oxley with a piece of skirting board that had been used as rendering

Conservators and contractors had hoped to be finished by this weekend, but they have now set a new target of September.

John Oxley, city archaeologist, told The Press: "There is only one Walmgate Bar, but mistakes have been made in the past. We do not want to repeat mistakes or add any of our own. It is a bit like wading through treacle now but it's necessary to go at that pace so we do not make mistakes.

"We want to make sure that once we have done this we are out of here for maybe 50 years and don't have to come back sooner."

He said the last major restoration, in 1990, had not fully dealt with the issue of weight distribution.

Two vertical timber beams were cut many years ago, meaning all the pressure of the timber-framed part of the building is now borne by the stone columns and a timber beam on top of them.

The fact that beam has begun to tilt means the beam could come off the columns leading to collapse, unless action is taken. Experts will be brought in to raise the timber by a few millimetres, to allow the weight to be more safely distributed.

These pictures show opposite ends of the horizontal beam that rests on the stone columns. At the southern end, pictured right, the beam remains mostly on the stone. At the northern end (nearest Foss Islands Road), pictured left, the beam now overhangs the stonework. At both ends, the beam has also begun to tilt, no longer lying flush on the stone.

Other timbers have been found to be severely damaged by rot or death watch beetle.

Mr Oxley said the cost of the project would not necessarily rise, even though it was now taking longer.

A separate difficulty has also arisen, relating to how to insulate the restored Bar, to make it more inhabitable for the coffee house operators who currently occupy the building, and any successors.

These images show some of the damage to the timbers, caused by rot and death watch beetle

Nigel Copsey, from the Ryedale-based Earth Stone and Lime Company has been brought in. He said modern techniques developed over the past 40 years caused needless complications, and said using traditional methods would be more successful.

He said: "People thought they knew better than 2000 years of practice - then wondered why we had problems."

Above and below: Mr Oxley at Walmgate Bar

The work on the Barbican of the structure has been almost completed, with a handrail added to allow public access, the heraldic coat of arms and plaque restored, and the paving on the road surface replaced.