Solid walls- thermal imaging

Some of the most dramatic examples seen in thermal imaging surveys carried out locally have been of the impact of the solid walls typical of homes in this area.


One home had lined their walls inside with insulating material on battens to create a warm inner surface; while others complained of rooms which had lengthy runs of cold external wall punctuated by windows. This is possibly the most difficult problem to tackle: external insulation is best (and most expensive), dry lining a good alternative if space and budget allows; and cheap and cheerful is lining with Sempatap. If you are considering building an extension, or renovating an existing part of the property, these options are worth investigating. However care should be taken to allow sufficient ventilation and to avoid the creation of cold patches at joins in the insulation, and the possibility of moisture condensation between the insulation and the wall.


An un-insulated stone house (17th Century) on the right, with a new Celotex insulated extension on the left: the line is clearly visible in the centre of the picture.

If solid walls cannot be insulated for financial or planning reasons, it is worth looking at other measures to reduce heat loss, e.g. the fitting of radiator foil behind radiators located on outside walls.

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Before (left) and after (right) installation of radiator foil. Note also that in the right-hand image, although the foil has cut down on heat loss, there are still patches where the radiators are fixed to the wall and conducting heat away from the room. In addition in the right-hand image the curtains have been left open on three windows to show how much heat loss can be caused.

There is a range of products for reducing the heat loss through the wall behind a radiator. The simplest and cheapest is a sheet of aluminium cooking foil attached to the wall with adhesive tape. Next in cost is attaching the foil to sheets of cardboard that fit behind the radiator. Special radiator foil can be used (about £7 a roll) attached with wallpaper paste or there are versions which are suspended behind the radiator (good if you have stone walls) Finally the most expensive option is to buy light-weight contoured ‘silver’ panels at a cost of £5 – £10 a radiator. A shelf above the radiator helps to spread heat into the room.