Damp on chimney breast

[Adviceseeker24]

Hi, we installed a log burner a few months ago, havent used in a while as warmer weather.
There are some small damp patches appearing either side of the bottom of the chimney breast above the hearth, a damp meter is giving a reading of 30% which upon reading is concerning! The patches aren’t wet to touch and the readings around the patches are low.
any ideas on what’s causing this? We’re going to get a roofer to check the chimney for any leakage points but how do we dry these patches out in the mean time?
house is a small cottage built in 1800s
thanks in advance

Is there adequate ventilation and good air flow, is the flue/chimney totally sealed?

Was the damp proof course breached when the new hearth/fireplace was installed?

As far as we’re aware it should be! We had a professional come to fit the flue

To be honest it doesn’t look like there was one round the fireplace, it was bare brick that was just filled in with filler to smooth the wall: there’s no damp around the rest of the walls so though

Firstly get rid of the damp meter.

In an 1800s property the most likely issues are going to be either water getting in through a leak, or use of cement instead of lime.

Damp proof courses are irrelevant, these houses were built without them and don't need them to stay damp free.

Thank you! Will get the roofer round to check for a leak

Is the filler new? If the damp is in this area I'd suspect the filler has reduced breathability.

Everything you need to know is on this website in the damp and condensation section:

www.heritage-house.org

Whoops missed the 1800 bit. Yes, there won't be a damp proof course.