Frame too narrow, missing, or
in the wrong place
It is sometimes necessary to supplement parts of an existing window to
provide the complete surface required for attaching the tape and membrane.
Attach a fixed supplementary frame
Use a length of square or rectangular rigid material such as timber or aluminium (eg. 30x20mm or 15x15mm) to make a second frame within the window reveal. Attach the timber/aluminium to the window reveal using glue and small screws or nails.
Attach the tape and membrane to the new frame as for a standard window.