"Merging" different wall types.

[Keith_K]

The plan I am busy with has several wall types, intentionally and relevant to the project, and so obviously a wall of one type will butt on to one of another type. I am getting one type "bleeding" into another rather than a "clean" join" and am unable to drag the bledding wall out of the adjoining one to make a clean meet.

I have spent several hours this morning reading the user manual, the help files etc. but I found nothing on this subject that would tell me why apart from an instruction on another matter to ensure that the "snap object" was switched on.

Here is a screenshot of what I mean. The "bleeding walls" are indicated by the red squares.

Any advice for which my thanks in advance.