What are your thoughts on this method?

[Jake2021]

Hi all,
Came across this ‘pro’ video on strengthening joists just wondered what your thoughts are?

I’m not sure if there should be a gap between the new timber as it seems the old joists are taking all the weight?
Could be wrong ‍

Best wishes
Jake

 

[johnny2007]

Doesn't do anything rather than making it stiffer.
Totally useless if you ask me.

 

[freddiemercurystwin]

That's not strengthening the floor but it is a tried and trusted method of spreading the new access floor evenly on the existing.