Four fire crews were called out to a fire in the derelict Orchard House buildings, formerly part of the old Rauceby Hospital, at Greylees, near Sleaford in the middle of the night, Friday/Saturday.
The call came in just after half past midnight when fire engines from Sleaford, Billinghay and Donington were needed to extinguish a room fire in a wing of the old buildings which are scheduled to be demolished to make way for new housing.
A report from the fire service states the fire fighters, wearing breathing apparatus, used two main jets to put it out.
The cause is not known at this stage.
* A Sleaford fire crew was called on Saturday afternoon to Sleaford Woods.
Approximately five square metres of tree roots and undergrowth were reported on fire at about 3pm.
The firefighters put the flames out with a hose reel, water back pack and drag, according to the fire service.
It is said to have been caused by controlled burning being left unattended and spreading.