Hi,

A friend has a timber framed house and is looking for a fireplace and a
gas fire (balanced flue or less likely power flue) which means getting a
hole right through the wall. We are not DIYing the job but I would like
to figure out how are the walls constructed and what should be the
correct "re"-construction of the wall/membrane by the fitters.

Does anyone have a pointer to diagram or similar showing the
construction of a wall? For example, from the inside we have
plasterboard on studs, somewhere there is insulation and some membrane
(waterproofing, dampness ???) and then the outer wall.

Example of an issue. One or two joists would be cut above the fire.
Should he expect a beam to be put across them where they are cut and
joined to the next uncut studs?

Another example. What damage can be done to the membrane which will give
structural problems later on?

TIA for any pointers.
Charles