The project was to replace a collapsing lath and plaster ceiling. The plaster was earth and lime with inclusions of animal hair. The laths were worm eaten as were the rather thin joists, two inch square wood which could be easily snapped in half. There was a prominent sag in one of the cross beams and one of the purlins was broken and was propped with a thin tree branch, many of the timbers still had the bark on.
We turned the sagging cross beam on its side so it was flat, put in an oak beam to support the rafters which were very bowed and unsupported by the broken purlin. We replaced the joists, nailed on new oak laths and plastered them with locally gathered clay earth processed by being turned to slurry, passed through a 10 mm sieve and then mixed with quicklime and lime putty to bring it to the correct consistency before mixing that with sand and sheeps wool.
This earth and lime mortar was a joy to work with and we were easily able to plaster the ceiling in one coat before flattening and leaving it to dry before applying two thin coats of lime finishing plaster made from lime putty mixed with fine dredged river sand from the River Torridge.