squelchy wrote:

I live in a terrace house with a 9m by 4.5m loft space which is all
open with no obtrusive w shape or v shapes to be seen. It has two part

Where are these part walls?

walls it does have 2 jiosts 8" by 2" on the floor and 4 (two each side)
one quite low to the roof and the othere about 1.5 meters up from floor
hight these rest on the party walls can some on please advice the best
way to creat a workable floor space I will be useing the area as

As the others said, "purlins" by the sounds of it. These can be taken
away if required but their function (stopping the rafters sagging in the
middle from he weight of the tiles) needs to be taken up by something
else like a dwarf wall.

storage and possible office I am awair that to convert this I would
need a 30 min fire barrier with stairs and loft insulation but I will
be unable to fit the stairs as have no room due to other work done on
the house before we bought it I have fitted a nice set of wooden loft
ladders that retract and this will surfice for my needs and I will be
fitting an excape velux after the flooring is done.

The rules governing stairs are somewhat relaxed for lofts, so you may
find that a "space saver" stair would be acceptable (i.e. one with
alternate treads cut away and a much steeper pitch than normal)

my neighbour has alrady converted his loft and terned it into a very
nice space he has fitted stairs and done a proper job on the face value
of it but I asked him for advice and he know nothing of the structual
forces at work and had just guessed the best wood to use he has also
not gone through building regs which I am not to chuffed about but dont
want to start world war three with them as still got to live there.

If he did it a while ago there would be nothing much anyone could do
about it anyway... (it would also give some reassurance that he got
something right since it is still there!)

My question is this what is the best configurational layout i.e jiost
on hangers or pun through the party walls ? if so could some one let me
know what the calculations are for the size of the wood or what wood I
would be best to use.

For joist sizing you can get some idea from the standard tables in the
building regs documents, or you can calculate the required sizes to meet
the loading, bending, and shear limits imposed both by building regs and
the nature of the timber. If you read through the into on my page here I
cover the information sources and the software that you can use to do this:

http://www.internode.co.uk/loft/index.htm

by the way I also have 4"x2" lengths of wood running from the frount
to the back of the house 9m split in to and resting on the centre wall
of the property.

If you have a central supporting wall then it is quite common to use the
same layout for the new floor. You place a extra 3/4" or 1" spacing
plate on the wall plates between the existing joists on all the walls,
and then sit the new beams on these. That ensures that the new floor
does not make contact with the existing ceiling.

For an example, see how I did my floor structure here :

http://www.internode.co.uk/loft/floor.htm

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/