Loft : boarding for storage few questions

[minority]

HI,

Probably asked a thousand and 1 times but I just wanted to have someone check over what I plan to do before I begin.

My house was built around 2011 and I am looking to floor a small part of the loft just for some general storage (Christmas tree and decoration and possibly a few other bits and bobs like empty suitcases.)

I have tried to make a drawing to help with my explanation but essentially I am considering flooring the section the are points to in my loft as it is right next to the loft hatch which I have now put a loft ladder into and head height should be ok.

My main concern are my joists they are 1.5in (3.81cm) by 3.5in (8.89cm) now my idea I have so far for doing this are:

1. Counter beam with similar dimension beams to then keep my insulation depth. The issue might be:
   1. Beam dimension are they to thin for the length/span I am trying to floor?
   2. There are stiffeners running across the beams which mean I can't bet the new beams to sit flat what are my options.
2. Loft stilts I am pretty sure I can get these flat on the beams but
   1. could you get variable height ones if I need to sit on the stiffener as my assumption is it bad to remove it?
   2. are they suitable for my beams?
3. Loft zone is my other option and I believe I can get them flat on the beam but will it add anything like extra strength as obviously this is the most expensive method?
4. Option 4 is don't do the area highlighted but the middle section which only has the small inconvenience that a beam runs mid height but not really a issue.