Structure of a Loft Conversion - can anyone advise?

[405 TD Estate]

I wanted a bit of advice - just an idea really of what might be possible/ involved in my loft conversion.

Currently the space in the loft is open - 1935 brick terraced house. The beams (about 2" square) and maybe 10 of them that run between the gutter line and the top/centre/middle of the roof are supported 1/2 way up by a substantial wooden beam running left to right probably about 4" x 1 foot in size to stop the beams saging 'in' i guess.

The whole of the space in the loft is empty.

Since this beam would intrudes into the living space quite a bit what are the options of replacing it? - what is normally done?

[John Rumm]

Rafters - 2x2 sounds quite small - 4x2 would be more typical.

Purlin. Yup they support the rafters mid (ish) span - or on large roofs sometimes there are two per side at 1/3rd and 2/3rds positions.

For examples see:

The whole of the space in the loft is empty.

Are you planning on adding a dormer on one side or both? Typically you would replace the purlin with a dwarf wall.

See about half way down the page:

[meow2222]

Thats a very light roof stucture, are you sure about those dimensions? If so, is the place really tiny? Or are they very close spaced?

You're not going to replace a purlin with anything even smaller than

4" - if anything the opposite.

If head height is borderline there is in principle the option of replacing the floor structure altogether at a lower height, and this can go as thin as 3" if necessary (3" solid floor, no joists), but of course it all adds to the cost.

NT