Hi Im building a timber summer house in my garden for all year use

just about to build the walls

from the outside in

does this sound ok

12mm treated shiplap
knauf breathline membrane
12mm sterling board
100x50 mm studs with 100 mm rockwool insulation
vapour barrier
plasterboard

would you reccommend battens between the knauf breathline membrane and the ship lap or is this over kill


it seems quite a high spec but i want it to be an all year summer house
plus i want it to last

I would also be interested on how to insulate the roof

This will be
two layers roofinf felt
18 mm ply
125x47 mm rafters
insulation
vapour barrier
foil backed plaster board

is this ok
do i need a gap for air flow


Im running 4 sleeper walls along long side

The joists will span front to back
ie 3600 mm long but supported at front and back plus in tow places in the middle

max span therefore 1200 mm

Are 150x47 mm joists too big

Im going to fit 18 mm ply on top
plus polystyrene insulation within joists

Im running the rafters front to back
ie 3600 mm span
I want to run a single purlin in the middle 4800 mm long

ie rafter span now 1800 mm

what size rafters and purlin for this roof

its going to be clad with 18 mm ply and two layers roofing felt

thx

urbantus

you definatly need airflow behind the cladding as trapped water will cause rot eventualy

my small workshop is of simmilar structure 12mm txg cladding 3x2" timber 12mm ext ply floor and roof havent got round to the insulation yet though

its 12 x10ft internal size
what size is yours!!!!

http://i21.photobucket.com/albums/b270/bigall2005/workshop001.jpg

http://i21.photobucket.com/albums/b270/bigall2005/workshop003.jpg

Quote:



heeelloo bodger

i am assuming you mean the grey cable comming from the socket down behind the chop saw handle and back up again!!!

all my sockets are high level the area below the "cable" is the work area
so instead if the cable trailing everywhere it goes from the socket to the work area via a hook above so the cable never gets in the way
so what you see is the excess lead too the sander keeping out the way