Rod Stewart is due to play the first concert at the arena being built by Lend Lease.

A spark from a welder’s torch caused the blaze in the roof which took 40 firefighters to put out.

A Hydro statement issued to STV read: “Lend Lease, our building contractor, has now completed its assessment of the water and fire damage arising from the fire at The SSE Hydro on Saturday June 8 2013.

“Whilst the damage is not as severe as first feared, there remains a number of areas, especially around the roof, that could still impact on the construction programme for completing The Hydro in time for the opening period.

“Many of these remediation issues have been addressed with the sub-contractors and loss adjusters but a number remain to be discussed and agreed.”

The statement continued: “As a consequence, the construction project remains on target for September completion albeit with some additional challenges that require to be fully resolved.

“Everyone involved in the project remains sharply focused on achieving our opening night concert with Rod Stewart on September 30.

“Whilst there remains some residual risk, the SEC team will do all we can to support the construction team and be ready for the September opening.

“We will continue to provide regular updates to promoters, artist management and fans as we work to clear these issues.”