This type of roof has been described earlier and reference can be made to Fig. 5.4. Clearly the truss is a major component in such a roof construction and is not easily replaced if removed to provide a clear roof void for conversion. The only real solution is to provide purlins to support the rafters and ceiling joists, taking full account of the fact that the new attic floor will also have to be supported by some form of purlin as it is unlikely with this type of roof that there will be any supporting partition wall below.
To break the length of span of these purlins, it may be necessary to extend up a structural wall from the ground floor through the existing ceiling, the other supports for the purlins coming from the gable and brickwork. It must be emphasised that without engineers' structural designs, no element of the main roof truss should be removed before some replacement structure is in place.
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