How do I beef up loft floor

[Basecoat]

Hi All

My loft is a big mess after I had new roof tiles installed some years back. Going into loft last sunday my loft is like a bombed site with loose crumbly morter every where so much so the fibre glass insulation looks in bad shape.

I am thinking of turning the loft into useable space but the ceiling woods are old 2"x3" and I am worried these won't support the weight of 8'x2'x3/4" chip floor boards I have seen in B&Q.

How can I beef up the floor timbers to support the floorboards. Thank you in advance.

Basecoat

 

[ree]

It sounds as though you have a pre 1914 house. The only remedy for the light section joists is to up to a larger section joist.

1. is the lower ceiling already sagging?
2. what does a "usable space" mean?
3. there might be difficulties in getting suitable lengths of joisting into the loft.
4. do you have a suitable access hatch to the loft?