S Casey wrote:

I've got a shed going up next week, and I intend to insulate most of
the inside (a single skin partition will seperate out the other
section)

Now, the entire structure will be of dip treated 2x3 framing with 22mm
cladding on top (excused the mixed metrics!), on the inside of which
I'll be putting a insulating polystyrene layer topped off with
plasterboard and then a layer of plaster.

The entire building will be 18'x10' with a 13'x10' room being
insulated.

My main concern at the moment is how the plasterboard will stand up to
the expansion and contraction of the wood?



Not too badly. My whole house is made this way, and its more flexure and
the initial shrinkage of the wall that has proved the problem. Tape the
joints well before skimming, and don't be tempted to try and use all the
plasterboard scraps. Board is cheap, making good splits later is not.


Now, my questions.

1) is this the right way to go?


Yes, tho I would use Celotex. not poloystyrene, for better fire safety
in terms of flammability and noxoious fumes. Use fool backed
plasterboard with polystyrene, to form vapour barrier.


2) How should I attach the plasterboard to the framing?


Nail it on carefully with big headed clouts. I have had zero success
with 'plasterboard screws' - they rip the top surface and the
plasterboard comes loose. YMMV


3) Would 75mm polystyrene be about right/too much/too little?


As much as possible. 75MM celotex even better.


4) How should I run a lighting ring given the PVC/polystyrene issues?


Dont use polystyrene, use celotex. Or Rockwool. Its as good as polystrene.

Tip. Run cables early, and decide where sockets etc are to go, mark on
studs.


Its probably better to have cables at the back behind insulation, wheer
they won't get nailed as you put up plasterboard.

Put up insulation. and if using celotex use the foil tape to seal. Bring
sires top teh front through cutouts, if you intend to use drywall
sockets or put in noggins to take steel boxes. Insyall boxes and coil up
cables inside.

NOW GET A FOAM GUN AND SEAL UP EVEYTHING to draught proof COMPLETELY.
Wish I had.

nail up plasterboard.

Make cutouts for wires and pull through. Fit drywall sockets if using.

tape joimnts with scriom, Skim and decorate

Install sockets.






Can you reply to the group please, I don't read the email address
provided above!