Tenants from 110 St Michael's Street in Shrewsbury were evacuated last Friday after a resident raised the alarm with Shropshire Council and a structural engineer deemed the property a danger to the public.
The authority has now said the demolition will take "a number of days to organise", and about 14 days to complete.
A section of the A5191 St Michael’s Street between the Flaxmill roundabout to New Park Road will be closed to through traffic in this time.
Sultan Road and New Park Road will remain open but are likely to be busy and drivers are recommended to avoid using these roads if possible.
Alternative routes for through traffic have been signposted out of town via Coton Hill and Ellesmere Rd and into town via Telford Way, Pritchard Way, Bage Way and Old Potts Way.
There will be access for anyone needing to get to their home or business along St Michael’s Street for the period of the closure.
Councillor Ed Potter, Shropshire Council’s cabinet member for economic growth, regeneration and planning, said: “We appreciate this closure will lead to some disruption for residents and businesses in the area and we hope they will understand the urgent nature of this.
“The safety of the public must absolutely come first. Work to demolish the building may take a number of days to organise due to the complexity of the building construction and the need to project both the public and other properties while the work is undertaken.
“The council continues to work with the owner to take immediate action because we have a building on a main road in imminent danger of collapsing.
“We hope that any disruption can be kept to as short a period as possible and we will keep residents updated via our website and social media.”
Temporary traffic lights were put in place earlier this week to keep the public well back.
The property, which is not listed and had a number of rented rooms, was evacuated and the residents were put into emergency accommodation.