"mo" nospam wrote in message ...
B and Q? Or will I have to look more local?

I always use a timber merchant in preferance to a shed. IMO B&Q and other
sheds are only there for when you run out of something between noon Saturday
and Sunday evening.

All the floorboards in my room are different sizes - I guess I will have
to give them exact measurements? (width, height and thickness?) and they
can cut them to order?

A timber merchant will, but you will incur cutting charges. It is better to
buy the next standard length up and cut them yourself. If you need
non-standard widths and / or thicknesses, then you will need to order in
advance and pay the machining costs.

Is there a cheap material you can buy to put on top of floorboards to make
the floor totally flat?

If you are replacing the floorboards and want a flat floor, the simplest
answer is flooring quality chipboard. For a really flat finish, screw the
chipboard down, using countersunk screws in deeply countersunk holes, fill
the holes and the slight gaps between the boards and sand smooth. However,
that is really only necessary if you are putting something on top that will
show imperfections, like the cork I put down in my bathroom. Carpet does not
need the extra work.

Colin Bignell