Currently, there is only a catwalk in the attic. Despite this, a lot is stored there using primitive shelves between the W-trusses. The W-trusses span 7.5 m and are constructed with upper and lower sections of 45x140. I don't see any obvious sagging at the moment.
Now I want to have a simple floor there (wood planking) that ends about 1.5 m before the outer wall/truss termination. My original plan was to install 45x-195 joists on the top side of the lower part of the trusses, screwing them together with the truss using bolts, thereby improving the truss's load-bearing capacity. However, I have realized that I would create a thermal bridge if I do so, and that I need to cross-lay the 45x195 joists instead (I need to raise it to get above the insulation with a few cm clearance). A cross-laying, however, will only impose a load on the trusses.
My question is, is it reasonable to worry about the trusses' load-bearing capacity in this case? After all, heavy items are not supposed to be stored there. The only concrete weight added would be from the raised floor.
