LyX: Same layout for floating table and longtable

Question

I am using some short tables in my document which are all placed in a float environment. I now have to create a multipage longtable which I want to look exactly as the other tables (with the same row height and line spacing, most specifically). I have put \renewcommand{\arraystretch}{1.5} in the preamble but that does not seem to affect the longtable outside a float environment. I didn't succeed either with putting that code immediately before the longtable, although it does change the row height. And why is the line spacing different (bigger) compared to the float table? How can I set the same row height for all tables in the document?

Bonus question: Is there a way in LyX to hide a table just like one in a float environment?

Answer 1

I finally found an answer for my case; it might be useful for others: In my preamble I defined \setstretch{1.43} for the whole document. The problem was that this adjustment seemed to affect the longtable environment but not the tabular in a table/float. So to get identical looking multipage tables I had to put \singlespacing before the longtable.