can i remove these old ceiling joists as there are new ones.

[DougBrooks]

we are currently redecorating (renovating more like) our old early 1900 3 story end terrace house, we have had a new tiled roof including breathable membrane and insulation also the dormer replaced and widened in what would have been the old attic side of the top of the house.
we are now working on the room below we can see that whoever did the job of making the space above liveable had already replaced the joists and i assume had left the old ones in place due to the plaster and lath ceilings and did not wish to disturb them.

, due to the fact that most of the plaster had come away from the lath the plasterer advised against skimming it due to the extra weight and that it could all come down. so i have removed all the plaster myself from the ceiling and noticed that the joists had seriously bowed , but above them are new ones.

So the big question is can i removed the old ones so i can have a flat boarded ceiling or should i start pulling out about a million nails from the old joists .and if so are they attached to the purlin/roof support?

I have included photo's , any help and advise is appreciated

 

[tony1851]

Can't see too easily from your pics, but are the old ceiling joists connected to the rafters? If so, they may be acting as ties, giving restraint to the roof to stop it spreading. If this is the case, removing them may be risky. On the other hand, if they're not fixed to any rafters, you should be OK removing them.

 

[DougBrooks]

Hi Tony thanks for the reply, i have just taken a few more pictures and added them to the same album if you would take a look at them when you get the chance .
i dont think they are directly attached to the rafters, the only place they may be attached is to the actual beam that the rafters sit on if that makes sense?

 

[DougBrooks]

I could still do with some advice on this , I am about to start the nail pulling as the plasterboard arrives tomorrow .

 

[tony1851]

On the pics, it looks as though the old ceiling joists are just nailed into the side of the main beam (aka purlin).
If this is the case, they are unlikely to be providing a tying function. They would be more likely to be ties if they rested ON TOP of the purlin, AND were also nailed to the sides of the rafters.
If they are similarly casually fixed at the other end, I very much doubt you'd have a problem if they were removd.

 

[DougBrooks]

Thanks Tony , i have just completed the task of de-nailing all the old joist's (after 2 hours and have blisters to show for it lol) , the plasterer has just been round to measure up for the 12.5 boards and said it wont be a problem as he will shim the boards to suit the ceiling so the old ones can stay put, it wont be mirror flat but it will be 100s of times better than it was before. , i am going to add noggins between the old joists and attach them to the new ones to try to prevent any movement , i know that the bow in them will not pull out but its more to prevent any more movement.