I did alot of research and decided to buy and old trailer tent trailer and build onto that rather than have a trailer built. I have built everything to fit 8x4 sheets and went for birch ply sides and Aluminium roof. A hatch at the rear and basic 240 hook up with internal lights.
Trailer is 4ft wide and roughly 7ft long.
(I am in the UK so my measurments may throw some of you Yanks as we dont understand inches!!
So first I stripped and painted trailer with Hammerite



Then added the wooden base and frame work. Underneath has a couple coats of bitumin paint to protect it.


Insulated the floor and cut the sides out of 12mm Birch Ply


3 xcoats of yachts varnish

and attached the sides to the base and started fitting the cross spars


all glued and sealant in each screw hole before screwed in to make water proof



On to making the rear hatch


Then the internal skin was added which is 4mm ply



I then insulated between the spars. I went for earthwool as my spars are 34mm wide so Cellotex was either to thin or to thick plus its expensive!
I also put in the internal lights and ran the wiring before the top skin went on.

Then put on 4mm ply and coated in more varnish


I also sealed the edges with PU40 sealant and cut the hole for the Fiamma 40 roof vent
Got the aluminium skin on, its 1.2mm ali and its floated on, attached at the front and back and also held on with the edge trim.PU sealent along all the edges and under the edge trim to make it all water tight.



next is the skinning of the hatch and getting it all screwed on and door hung