|
If the last time you looked in your loft was to bung in a few surplus boxes when you first moved in, it’s time to grab a torch and find out what you’ve got. You must be realistic about the possibilities. Take a tape measure and note the ceiling height – it needs to be no less than 2.3 metres to give enough headroom. The steeper the slope (or pitch) of the roof, the more suitable it will be for conversion.
You should also take a note of what the support for the roof is like:
Single roof is the most basic construction, with a triangle of rafters (these are the top of the triangle that support the tiles) and joists (at the bottom). The easiest to convert but not common as it’s only suitable for light roofs and short spans.
Double or purlin roof is very common in older houses and is the next easiest to convert. Planks of timber called ‘purlins’ run horizontally to support the rafters about halfway up, with ‘V’- shaped struts bracing every fourth or fifth pair.
Trussed roofs can be computer-designed and prefabricated off-site, so are more prevalent in houses built since the 1960s.
The rafter and joist triangle is supported internally by a ‘W’ timber strut, making it the most awkward to convert.
|
