Thank you Nick & Alex.
I’m new to the BAA and did a BIT of a search and saw there was quite a lot on the subject. I guess with the post I was wondering if there was any up-to-date “solution”. Nick, I will definitely seal the concrete – always intended to, but ran out of Summer and thought it might be too late temp. wise. I’ll check what B&Q have and at what temps. the products can be deployed. The problem with dehumidifiers and heaters is electricity cost of course – perhaps I could put up an array of solar panels – that CAPEX sounds expensive! Paul