On Wednesday, October 17, 2012 4:05:44 PM UTC+1, Tim Lamb wrote:
In message , John

Rumm writes

On 17/10/2012 11:49, GMM wrote:

Sorry chaps, a bit of a long post but I have tried to get all the

essential information in (!) Undoubtedly

there will be something I've missed out, even so....



Couple of thoughts... someone in here reinforced their existing joists

rather than install new.



The other.. don't allow the new timbers anywhere near the lath and

plaster. We once had a chalet bungalow where the previous owners had

stiffened up the old loft floor to take the new bedrooms load. These

joists spanned the outside walls but were not attached to the old

ceiling ones. Inevitably the new timber moved and pinged nail head

plaster off the downstairs ceiling.



--

Tim Lamb

Absolutely - If there was too much danger of damaging the ceiling, I thin it would make more sense to just take the lot down to start with, then put a floor and new ceiling into the space, which was what the builder did next door in the same place. They were dropping the ceiling height however to accommodate a loft conversion.