Cavity wall insulation

Double glazing could also cause problems in the winter. With double glazing, the water would condense on the next-coldest area

Terry Bryant asks pertinent questions about cavity wall insulation (Letters, PE December).

For 23 years I lived in a detached house built in 1908. The house was of brick construction with cavity walls up to the gutter level; above gutter level the gable ends were 9in thick without a cavity. The damp-proof course consisted of three courses of blue brick.

I decided not to install cavity wall insulation for the same reasons as Bryant. A neighbour in a similar house did install insulation. Within a few years they experienced dry rot.

Maybe plastic balls 5mm in diameter would be satisfactory.

Double glazing could also cause problems in the winter. My house, with six living in it, had central heating. The rooms were at different temperatures. Most mornings in winter we wiped the condensation from the windows. With double glazing, the water would condense on the next-coldest area.

Brian Cowell, Hucclecote, Glos

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