An almost flat roof is placed over the top.
Loft conversion roof structure.
This option is the most expensive as it requires the complex removal and rebuild of the existing roof.
Changing the roof structure for a loft conversion.
This design is used where the original roof had little or no headroom and creates sufficient volume for an additional storey.
These are suitable for most types of home including terraced house loft conversions.
This could be a hip to gable loft conversion or a mansard conversion for example.
This type of loft conversion involves one or both slopes of the roof being replaced with a new structure with very steep sloping sides almost as steep as the walls.
In the roof space as the name suggests the ridge board is the length of timber which runs horizontally along the apex of the roof.
However the average dormer loft conversion with a double bedroom and en suite costs about 35 000 45 000.
Most loft conversions employ at least one pair of steel beams to support the new floor structure and the roof slopes at purlin level and sometimes also at ridge level e g.
Internal roof elements to consider during loft conversions consist of a number of sub structures such as ridge boards rafters purlins joists wall plates and steel beams.