Civil Engineering Reference
In-Depth Information
Chapter 11
Solutions
This chapter examines ways of converting three of the main roof construction types and
also roof replacement as a possible solution to the problem of providing additional accom-
modation in the roof space. In all cases the author has assumed that the roof structure is
sound and that repairs are not necessary. Should this not be the case then these will be the
subject of separate careful inspection and specification for the work. It is assumed that
roof coverings are also sound and that structural supports have been checked and are cap-
able of carrying the additional dead loads (those from the structure itself) and the live
loads of furniture and occupants.
The roof types to be examined are:
(1) The common roof (see Fig. 1.10);
(2) The bolted truss roof (see Fig. 4.5);
(3) The trussed rafter roof (see Fig. 5.5).
Having examined the above roof types, consideration will be given to the possibility of a
replacement roof structure which may be necessary if the roof shape is totally inadequate
to provide usable space, or if the roof structure is in such a bad condition that repair is
considered to be uneconomical. In all cases, a simple gable-to-gable straight ridge roof
will be considered.
Basic Accommodation
Figure 11.1 indicates basic requirements to be achieved:
Establish room height required, not forgetting that new floor joists will effectively raise
the floor level above that of the existing ceiling joist level in the loft.
Establish over what width of building the room will have practical use, bearing in mind
the side wall height regarded as tolerable.
