Okay - so regular plaster may not be suitable to plaster over laths; I hadn't thought of that possibility.I am not a plasterer but I believe that horse hair lime type plasters were originally used to deal with both the gaps and suction.
I would expect that you need a specialist plasterer (and pay a premium accordingly).
If you can find one who will want to do it.So if regular plaster cannot go directly onto laths, and needs to be a lime plaster - so this needs to be a specialist plasterer only? Regular plasterers can't use lime plaster directly onto laths?
(In case relevant, the house is not listed).
Originally I had assumed regular plaster could be placed onto laths by a regular plasterer, and if this was the case, it would mean there wouldn't be the extra time/expense of removing laths and placing new plasterboard in place.Is there a reason why you don't want to remove the laths and use plasterboard?
possom i see you have been asking this question since 2018? If the laths are bare there is nothing to stop a backing coat of bonding being floated on you will have to treat the laths then apply whats called a pricking up coat followed by a scratch coat then top coat the exact same procedure as if you use lime "ive done both" if you go the board option there will be a lip around the wall where the old plaster on the ceiling would have been and it will need to be chopped out and filled as the board will not quite reach it , the choice is yours wich way you want to go btw there has is lots of posts on this subject over thet years that you can readOriginally I had assumed regular plaster could be placed onto laths by a regular plasterer, and if this was the case, it would mean there wouldn't be the extra time/expense of removing laths and placing new plasterboard in place
I now realise this wouldn't be the case.