In message , Harry
Bloomfield writes
Bill laid this down on his screen :

When you push the gutter into the corner piece, it is loose. Is this
right? I thought it should clip together. Have we missed something
obvious?

Alternatively, it looks to me that, if some of the rubber seal could
be stuck to the outside of the gutter, it would make a tight fit. Is
self adhesive rubber seal of this type sold?

You position the gutter over the corner piece, hook it under a clip at
one side molded into the corner piece, then snap it into the opposite
clip. The black line on the white item, is the rubber seal - no other
seal is needed.

Well, he asked me to try it and that's exactly what I did, but the
gutter is a very slack fit in the corner piece.
Assuming the gutter is attached to the summerhouse wall, the corner
piece will hang there about 1mm below the gutter, leaving a gap.

He was saying that he had plenty of sealant, but it just doesn't seem
right.

Could one 76mm be internal height , the other external and different
manufacturers?

--
Bill