Non-destructive ways of finding out if you have cavity wall insulation

Section62

Chickereeeee said:

Section62 said:

Chickereeeee said:

ris2015 said:

Check top of wall from inside your loft space.

That's my suggestion. I can put my fingers down the gap there in mine. 

Unfortunately that method:

1) Relies on the cavities not being closed.

2) Relies on the cavity being filled to within finger-length of the top

3) At best only gives an indication of what the situation is at the top of the wall.

Then you can drop the endoscope down (if its not 1). Drilling a hole only gives you the situation at one point.

Ok.  But there was no mention of using an endoscope in the posts I quoted, and ris2015 said "Check top of wall..." which implied only looking at the top, rather than using this as an access point for a more comprehensive inspection.

The principal point being that the situation at the top of the wall is not necessarily representative of the wall conditions adjacent to the habitable space lower down, particularly (for example) with gable walls where the part above upper ceiling level may be uninsulated.