TRANSPORT chiefs have admitted they knew about “workmanship issues” on the Queensferry Crossing before it opened – but didn’t tell the public.

Earlier this week it was announced the new bridge will be closed to traffic heading towards Edinburgh for five days, just three months after it opened.

Now it has emerged Transport Scotland knew the road surface around the crossing's expansion joints was laid too high in August, but kept the discovery quiet as it worked out how to fix it.

Michelle Rennie, director of Major Transport Infrastructure Projects at Transport Scotland, said contractors only came up with a solution to the issue “a couple of weeks ago”.

She said: “At the moment the surfacing has been laid marginally too high either side of the joints, and that is a workmanship issue. The joints themselves are fine, but the concern is about the impact that the use of the road at 70mph would have on the joints.

“We knew that there were some finishing works that would be required before we moved to 70mph. Until recently, we weren’t aware of what the solution would be for these surfacing works, and what sort of impact it would have on road users – or indeed, what lane closures, if any, would be required.”

The £1.35 billion Queensferry Crossing was opened to traffic on August 30, eight months behind schedule. At its launch, First Minister Nicola Sturgeon hailed it an "outstanding achievement".

Ms Rennie said fixing road surfacing was "quite a weather sensitive operation", adding: "What we didn’t want to do was alert the public to potential dates, and then the weather changes in the intervening period.”

She said the partial road closure, which will last until 6am on Wednesday, will cause “two to four minute” delays during rush hour as southbound traffic is redirected over the Forth Road Bridge.

And she admitted there would still be “some lane restrictions” between now and next September to allow for additional finishing works.

The Queensferry Crossing is expected to move to a 70mph speed limit before Christmas, when the Forth Road Bridge will also open to public transport.

Jamie Greene MSP, Scottish Conservative transport spokesman, said there were some “serious questions” to be answered over the “bridge fiasco”.

He added: “Motorists and commuters must be dismayed. At no point were road users, whose daily lives are now thrown into disarray, informed that there were impending closures.

“To make matters worse, we now know that there are potentially more closures to come. Commuters just wanted a bridge that would get them to work on time."

Scottish Liberal Democrat MSP Alex Cole-Hamilton accused transport leaders of rushing the bridge’s opening “to avoid financial penalties or adding to the existing eight month delay”.

He said: “We need to know exactly what other works are in the pipeline to make the bridge fully operational and how this will impact upon its users.

“Closing the southbound lane for days will cause further disruption for my constituents."

Quizzed on the five-day closure at a Holyrood committee, Ms Rennie insisted Transport Scotland did not know the potential impact of the botched workmanship when it discovered the problem in August.

She told MSPs: “The thing that causes the greatest disruption on the road network is driver confusion, so what we didn’t want to do was put out dates and then change those dates.”

She said there were also “minor snagging issues” with the bridge’s wind shielding which would be fixed.

Transport Scotland confirmed politicians, including economy secretary Keith Brown and transport minister Humza Yousaf, had not been made aware of the workmanship issues until last week.

A spokesman said: “The issue was identified in late August and expert advice indicated this did not require to delay the opening of the Queensferry Crossing.

“In the interim period our contractor has worked with suppliers to identify an appropriate solution. Meanwhile performance of the road surface and expansion joint has been monitored with traffic running on the bridge and it is clear the work is required prior to moving traffic to a 70 mph limit.

“Ministers were informed about the issue and the works required to address it on November 21. As a favourable weather window is required to commence the operation a decision was taken to go ahead with the works on November 27 on the basis of weather forecasts. Once this decision was taken an announcement was made to inform the public.”