loft with unusual wall plate can I convert

[lionquinn]

Looking to convert the loft been up to have a look and the wall plate is on top of the existing ceiling joists and there is no wall plate under that.

I have no clue how I will put floor joists in. Has anyone else come across this set up in a loft.

I have a couple of pics.

 

[freddiemercurystwin]

Typically in a loft conversion a couple of steels are fitted on each side at floor level which support the existing rafters via structural stud walls, the new floor joists then span between the new steels, the new floor will not extend out to the external walls. But it would help if you explain more about how your existing roof structure works with some better wider angle pics.

 

[Doggit]

Assuming you have a central wall, have a chat with Building control, and see if they'll let you put a 5x3 beam on top of the celing joists, positioned over the wall, to then allow you to hang the new joists on to.

 

[tony1851]

You can put the new floor joists directly on top of the wall plate, and directly above the run of the ceiling joists.
If you need to get them lower for headroom, you can notch the underside of the new joists.
If getting them under the felt is a problem, you can chamfer the tops of the joists.
It's really not a big problem.

 

[Doggit]

But you may need to raise them about an inch to clear the lath and plaster from the ceiling.

 

[John D v2.0]

Is it a raised tie roof? Ie is there a sloping section between the upstairs bedroom ceiling and wall?

 

[bobsuerita]

its was very common in the 50's to pole plate on top off cieling joists as rafters were often 75mm to get full bearing so no problem converting
my only concern with some of the above posts about putting new joists on top of plate part of that roof looks canter levered by may just be the angle of the photo

 

[catlad]

I'm intrigued what type of roof tile is on your roof?