Hi, We recently had a loft conversion done, but due to poor design the space is not suitable as an extra bedroom. It currently has 2 small dormers; and we now (finally) have planning to create a large dormer. The new plans require us to change over the old steel (2 for the floor and 1 ridge). Now that the purlins have already been removed and steel in place, when we swap over steel work will the roof be stable during the works. We've had one builder who told us the whole roof has to come down. They quoted us £60K. Another told us that it wasn't a problem and acro prop support from the floor below would suffice without having to take the roof tiles off. Is this really the case? Please advise. Thanks in advance.