Last month Shropshire Council shut off St Michaels Street in Shrewsbury amid concern that number 110 could collapse.
Emergency work has now been carried out to stabilise the house – ahead of a decision over what do to about its future.
The work from Derbyshire firm Restek, started on Saturday and managing director Tim Knight said that within 48 hours they had managed to stabilise the house.
The work has seen the space below the building's archway, and the corridor leading inside from its front door, filled with pipes and geopolymer foam concrete – it means both are completely blocked and impassable.
The combination creates an incredibly strong honeycomb structure, which increases the load the building can bear – a measure which will allow a decision to be taken over what happens to the building. Shropshire Council's structural engineers have also said St Michael's Street can reopen.
The corridor section was put in using a tele-handler.
Mr Knight said: "We used two very big 600ml diameter pipes stacked on top of each other, put them in with a tele-handler and grouted around them.
"It becomes one solid homogeneous mass where the corridor and the arch are.
"There are 200 cubic metres we had to grout. That is now one solid structural mass of geopolymer and the pipes as well and that what the building is standing on at the moment."
Shropshire Council had said earlier this week that there were concerns the building "could collapse at any time", and that demolition could be "the only option".
Speaking earlier this week Ed Potter, Shropshire Council’s Cabinet member for economic growth, regeneration and planning, said: "The safety to the public and the adjacent properties have been our key priority. This has been a unique and complex situation, and our teams have been working round the clock to help the owner choose the safest and best option to first secure the property from imminent collapse, and then look at the safest options to demolish the building, if it can’t be saved.
“Over the past week, more technical information has been gathered and analysed, which allows us to reassess the risks further, and gives us a much better understanding of exactly what risks we are dealing with and help the owner make the right decision.
“Once the building is secure, we will be able to reopen the road. The owner, with the advice from structural engineers will make a decision whether to demolish or repair the property."
110 St Michael's Street comprises a large town house located within the Shrewsbury Conservation Area, which the council understands was built as an integral part of the adjoining terrace in the 1850s.
Residents were evacuated from the building last month after a resident raised the alarm about its condition with Shropshire Council.