A loose panel was discovered after high winds in January forcing the closure of the A320 Victoria Way while checks and repair work are carried-out.
In her latest update Woking Borough Council leader Ann-Marie Barker said work will last at least another month.
She said: “Over the past week, Sir Robert McAlpine (SRM) has completed works to secure the panels identified to be at a greater risk of detachment and preparatory works have begun on the remaining cladding panels in a phased and prioritised approach.
“Despite this progress, SRM expects Victoria Way to remain closed until at least the end of March which is disappointing news and extremely frustrating for all. I will continue to apply pressure to reopen the road as soon as it is safe to do so.
“Work continues to develop a long-term solution and this has been aided by exterior cladding specialists who are conducting detailed investigations to determine the cause of the detachment.
“It is imperative that the reasons for the failure of the cladding system are fully understood in order to design a permanent solution.”