Attaching new ceiling joists to walls

[Lauren11]

Hi There,

I have recently bought a 1900 end terrace and we are in the middle of a complete refurb upstairs.

On removing the old lathe and plaster ceiling we have discovered that it was bowing because the joists are bowing.
They are only 2X3" and span approximately 4m (the room is not square which doesn't help) and spacing ranges from 30-40cm.

We want to put new joists next to the old ones so if in the future we want to convert the attic we don't have to do this business again.

The old joists are attached to the external wall and rafters at one end and then attached to an internal load bearing brick wall and the joists heading off into the adjacent room.

The question is can we get away with 6x2 joists lying next to the old and then bracing them together to level the ceiling? with slight tapered ends to fit under the rafters?
And... I hear they need to be attached to the wall aswell, how do we do this with out removing bits of roof?
Is there some kind of bracing bracket?

Thanks

 

[freddiemercurystwin]

You would need something more like 50x200.

In anycase adding new joists to create a new floor for a loft conversion is not always that simple, you will need a structural engineer to ensure your existing wall is adequate to support the new loadings, often existing structure will need to be removed from the loft space and the loadings transferred into existing or new structure which will also likely have a bearing on how the new floor is constructed. Otherwise you could be wasting your money.