hi, I have now got my hi top fitted, using tiger seal as advised on here. Brilliant stuff! I have also injected expanding foam around the sides and front and rear where ply floor I have put in roof meets the fibre glass top. (I left a small gap all the way round!). I now need to line the sides and top of the fibre glass top. How do I fasten/bond to the fibre glass so that I can fasten side panels and roof lining? I am not sure yet if hi top will be bunks or storage! Still all needs to be lined though. Also how do I stop/reduce condensation? Thanks for your help as usual.
you could tiger seal battons to the hitop, where you need them........ i have seen it done this way........the roof vent will need a frame inside which will hold the center up
mr leisuredrive uses the plywood side panels to hold the ceiling ply and insulation up, but the roof has point built in to fastern the side panels to......
As Mok says, I have done mine earlier in this year, Take your time and cut some battens to fit the profile of the roof/hi top and bond these on, I used the multi layer insulation that is a composite screwfix amongst others do it, got mine by the mtr loose from Olearies at beverley,
Stuck this on with the same gunk as the battens, Got some cheap 3mm plyboard from same folk, as it was in the cupboard / painted over got the the yuckest they had (read cheap £6 for 6x3)
So far it has worked 100% with no condensation forming and noticably warmer in the upper rear cupboard,
I have also injected expanding foam around the sides and front and rear where ply floor I have put in roof meets the fibre glass top. (I left a small gap all the way round!). I now need to line the sides and top of the fibre glass top. How do I fasten/bond to the fibre glass so that I can fasten side panels and roof lining? I am not sure yet if hi top will be bunks or storage! 
Still all needs to be lined though. Also how do I stop/reduce condensation? Thanks for your help as usual.
