2 Experiments with budget 6mm MGO panels, dry lining or grp frame & Kingspan or cardboard insulation

6mm Mgo board screwed & glued ( to seal edge ) to supporting frame

Close up (25mm -32mm drywall screws used )

Close up of frame edge ( 2m long DES - Door edge strip )

Door frame off cut corner braces screwed in

Mid bean inserted

Foil sided Kingspan (80mm ) inserted . It will have expanding foam gluing it togethere & sealing edges to reduce thermal bridge

Close up

The second prototype was tried , using drywall steel frame & cardboard in fill. The edges were sealed  with silicone sealant & expanding foam . This seals the air inside the cardboard inner.

WARNING: Although the outer frame & Mgo board is highly fire resistant, the cardboard inner is flammable, so should one be used in low fire risk out buildings.

Alternatively the frame can be made of dry wall, which for reduction of bulk in transport, can be stored inside a larger size length

Prototype 2 ( steel drywall frame, cardboard box insulation, silicone sealant  & expanding foam  ) 


 Frame is lined with folded cardboard

End sealed with silicone sealant

Frame sccrewed & glued

Close up

Corner braces screwed in




Folded cardboard boxes (triple wall ideally ) inserted

The mid beam was made by screwing off cuts of drywall together , having slid one into another

Expanding foam screwed in to seal edges of cardboard to increase insulation value & seal air gaps

A sheet of plastic was placed on drying foam & a 12mm ply board screwed down to keep foam expanding into air gaps & not escaping. Plactic sheet used to stop foam sticking to board.

If the pressure of the foam expansion bends the board, a machine press, like our prototype here may need to be used like here

https://cabinznet.blogspot.co.uk/2016/11/machine-press-prototype-built-from.html