We have applied insulation to the ceiling of our restricted height cellar by using flexible multi layer thermo-reflective insulation sheets with a very low U value of 0.19 W/m2 K. Cutting the sheet into strips and stapling these between the joists with a strong staple gun means no loss of headroom in the cellar and hopefully less heat escaping from the ground floor rooms above. We'll have to wait to see how effective it is when winter really bites!
