Loft conversion cladding, anyone?

[Lindyboo]

The latest bee in my bonnet is to plan a DIY conversion of our small loft/eaves space (unlisted cottage). I’m unclear on what is usually used for cladding the roof timbers, but have assumed that either tongue-and-groove planks or plasterboard is the thing, with appropriate insulation behind. Both of these will of course put weight on the roof timbers, though the timbers are in decent condition.

Anyone done this sort of conversion and what did you use for cladding?

Thanks.

 

[Zebra]

I think the question of what you use as the inside wall/ceiling covering is an aesthetic one, and the real issue is one of condensation and airtightness. If your loft is currently closed away from the house, and therefore cold, then it is the ventilation of the loft space via the eaves that stops the rafters from getting damp, with the associated risk of mould and woodworm.
Are you planning on removing the hatch and having stairs instead, or some similar arrangement, which would make the conversion part of the existing house's "thermal envelope"?
If so, then you are introducing two risks. One is that of warm air from the rest of the house bringing moisture into the loft space where it might condensate on cold areas. The other is that of the removal of the current ventilation into the loft space.
Ideally you would need to achieve a good level of airtightness around your new living space, separating it from the colder air outside. Also, do you have ridge vents? You may need to install some to maintain the ventilation to the rafters.

 

[MatthewC]

I agree with Zebra. I can never understand how rafters can get ventilated enough when people squeeze in insulation and cover them all with boards of any sort. Or even worse, people insist on showing every rafter and so they cram the insulation and boarding all in between the rafters - any broken roof tile and the top of the rafters will always be damp.

Don't forget to consider the need for Building Control because you will be affecting a "thermal element", quite apart from the access question if you intend to use it as a bedroom.