Engineers inspecting the Trinity building tower changed their opinion that the structure was dangerous to being stable, in a matter of weeks.

The contractors and the council had widely differing opinions on the safety of the building, it can be revealed.

Contractors on the site, acting for owners and residents, initially said the building was a serious risk and could collapse after movement sensors were triggered during a storm in January.

READ MORE: We’re getting ‘omerta’ from council over Trinity tower say residents

They pointed to poor maintenance and substandard repair work over a number of decades on the 164 year old A-listed tower that can be seen from across Glasgow.

But just the following month they had changed their mind and a report said the tower presented a low risk and it was stable.

Glasgow Times:

The council however, said that the tower required bracing and timber shoring in the short term and in the long term a programme of strengthening works.

Meanwhile, dozens of residents were locked out of their homes, with no access to possessions and no idea for how long.

Inspection reports and communication between the council and the contractors acting for the residents association show the gulf between the conclusions reached by both parties.

A plan has since been agreed on work that should allow residents to be back in their homes next month, both in the Trinity building and in surrounding properties that were evacuated in January.

READ MORE: Update: Glasgow Trinity Tower work due to be completed in five weeks

The reports, released under Freedom of Information, show the initial conclusion of contractors, project engineers, Will Rudd Davidson.

They said the tower has been “allowed to deteriorate at an ever-increasing rate”.

It concluded:  “The impact of a partial collapse of both wall faces is highly unpredictable, ranging from significant debris fall through the building to progressive collapse of the entire structure.”

In February however, the contractors issued a Verification of Collapse Risk report.

It stated: “The Tower structure is currently stable and has a very low risk of full collapse on to the surrounding areas.

“Whilst the tower has suffered significant damage during its life, its structural integrity has not been compromised to the extent of becoming unstable. It has remained in an overall structurally stable state, with all recently gathered evidence showing that it is at very low risk of overall collapse and should remain so in the short term.”

The council  said it was not satisfied there was a low risk and maintained the stance it was a dangerous building,

A council inspection report stated: “There is clear evidence of past attempts to repair cracks, replace lintels and replace rot affected timbers. None of the attempted masonry repairs appears to have been effective.”

It concluded: “Given the nature of the building construction and the structural defects evident, the risk of a sudden catastrophic collapse should be considered to be high. The building should be considered to be unsafe.”

In a response to the verification of collapse risk report the council said It was not clear why the medium risk of progressive collapse January report had changed to the opinion of a lower risk mentioned in the later February report.

The council stated: “The calculations (of the low risk)  are based on conjecture and assumptions, should not be taken to represent fact.”

A spokesperson for Will Rudd Davidson, said: “Our report at the end of January was a precautionary snapshot of the situation subject to full consideration. 

"At that time we advised there was a risk of partial collapse. However, once we had undertaken a thorough inspection and review over the following few days,  any structural issues were found to be localised and did not indicate that the Tower was in fact at any higher risk of collapse than it has been for decades. 

"We have advised Glasgow City Council of this on several occasions. Based on our factual monitoring, detailed measurements and expert calculations we disagree with many of the points made by the Council in their reports.

"Our most recent report shows that the Tower is not at high risk of collapse and provides robust and scientific evidence that answers issues raised by Glasgow City Council regarding any risk of collapse.”