How does my attic look? (plan included)

[smp50]

Hello. This attic is in a small 1935 end-of-terrace house, ex-LA.

http://i.imgur.com/XaDpx.png

The "walls below" markings are very approximate, but the point is that there are walls below somewhere kind of in the middle.

There is currently 100mm of insulation between the 90mm members.

How appropriate is the current arrangement for typical storage?

If it's OK as it is then my plan was to board across the lower level (such that the 150 x 50mm beams will protrude).

If that's not acceptable then I suppose I could sacrifice 150mm of height and raise the whole deck up to the top of the two larger beams, of course insulating the cavity thus created. Either way, I mean to re-wire the upstairs lighting (the cables are in the attic), and though I'll lay most of it around the edge, what I do with the "floor" will somewhat affect my plans for that.

What do you suggest, and what must I take into account?
Any pointers on roof/floor anatomy terminology would be appreciated, too, as I don't know how to refer to each type of "beam" etc.!

thanks,

 

[big-all]

you would be fine going from 400-600mm each side off off the hall walls dependant on what gives you maximum economy on using boards

4x1" would do on the area and help reduce the load and sag likely

 

[smp50]

you would be fine going from 400-600mm each side off off the hall walls dependant on what gives you maximum economy on using boards

4x1" would do on the area and help reduce the load and sag likely

Thanks.

And to go out any further onto the ceilings would I need to reinforce everything somehow?

 

[big-all]

you would need major structural work like steels

are the ceiling timbers 4x2" or bigger ??

 

[smp50]

you would need major structural work like steels

are the ceiling timbers 4x2" or bigger ??

See the diagram - they're about 90 x 50mm, so yes that's probably a 4x2, I think?

 

[big-all]

the trouble you have is they are to hold the ceiling up and not much else apart from light storage so any timbers added detract from the capacity
although the added timbers do spread the load over a larger area