Strengthen joists to an existing loft extension

[Wiggy000]

Hi everyone,

I hope someone could shed some light on a predicament i'm in with regard to an existing loft conversion. The property i'm in at the moment (end of terrace 1930's) has an existing loft conversion, which is split into 2 rooms, one of which has plumbing for an en-suite bathroom, from lifting up the ply flooring it seems that the original ceiling joists are still in place (4x2). from reading posts these are not really strong enough.

As the extension is already in place i believe i'm limited as to how, or if i can strengthen these joists, coming up from below is definately not an option, and if it can be avoided i would rather not start ripping down walls, although lifting up the flooring isn't a problem.

Is there any techniques i can use to try to strengthen these joists, at present they span from front to back of the property, approx 8m with a loadbearing wall below in the centre, i was planning just to use this space as a bedroom for me & my partner with the ensuite, although not planning to have any heavy wardrobes etc up there.

Any help would be greatly appreciated

 

[Deluks]

Sounds v.dodgy.
Are you sure there's nothing underneath these 4x2's? Is the ceiling below directly attached to them? and the ply floor is directly attached to them on top?
Is there a staircase going up to this loft room?

 

[noseall]

Very dodgy. A 4"x2" could span up to 1.8m at 400c/c, so i guess you could pop a few steels beneath.

 

[lammiegb]

hi to get to 2009 regs i would upgrage your joists lay beside and strap together 9 by 3 inch running from out side plates to load bearing wall you have prob were stair runs up then you can build dormer off this if req via planning per good luck tegards kevin .

 

[ColJack]

do you need to raise the 9x3's on 10mm spacers and not fix to the 2x4s to isolate it from the ceiling below?

 

[Wiggy000]

Hi,

Thanks for your replies, yes it looks like the ceiling below is directly below and there is a staircase coming up to floor level, the ply flooring which is fixed to the joists.

I assuming that by laying larger joists this will raise the floor level and mean existing partitions will need to be removed and rebuilt?

am just removing the old bathroom so will start ripping out soon, hopefully it might shed a bit more light...didn't think there would be an easy way..haha