Every time the report mentioned death-watch beetle, it seemed to intensify the menace by quoting its Latin name

It is not every day that one has to run up a chainsaw in a tight corner near the ceiling of one's sitting room, with exposed electric cables hanging out above and below. But desperate problems demand desperate solutions.

I should love to know how old our farmhouse is. We reckon 300 years at least, and a visiting dowser, as he swung his pendulum in the kitchen, once got a message that building had started in 1681.

When we bought the place 10 years ago, three centuries of settlement had left the house without a single upright wall or right-angle corner. In particular, subsidence had played havoc with the windows in the western end. Some of the stone mullions had lurched to the right, some to the left, and the coating of pebbledash stucco, put on as a weathershield maybe 50 years ago, had cracked and bowed.

In short, the house looked awful, and we vowed one day to put things right. Now at last we have started - and, sure enough, the old building has struck back.

The lintels above the windows were once baulks of oak four inches thick and 12 wide. Removal of stonework and plaster revealed that they are now largely powder.

I had always understood that if your house is infested with death-watch beetle, in the still watches of the night you can hear a faint clicking noise as the little brutes chew their way through beams or knock their heads against wood as a signal to their mates. Well - for 10 years we had listened acutely and heard nothing whatsoever; so it was an unpleasant surprise to discover what a feast they had made of our timbers.

Of course, it is possible that they quit or died while Queen Victoria was still on the throne. Nevertheless, at some stage they had concentrated their efforts on a most vulnerable spot, where a main beam that carries the living room ceiling rests on a lintel over a window.

Not only had the lintel been pulverised: the end of the beam had also been chewed into dust. With decay so advanced, there was a real chance that if we had not taken remedial action soon, the ceiling might suddenly have come down.

The immediate answer was to install a forest of Acroprops, the wind-up supports so beloved of builders. There was one in the cellar, floor to ceiling; another directly on top of it in the sitting room, ditto; two in the window opening - and for several nights we scarcely dared breathe in our bedroom above.

What finally drove us out was the searing stink of the insecticide with which a specialist firm injected the surviving beams. Every time the inspector's report mentioned death-watch beetle, it seemed to intensify the menace by quoting in brackets the Latin name, Xestobium rufovillosum.

Not all our discoveries have been so traumatic. One is that the main roof used to be mansard - that is, more steeply pitched at the bottom than at the top, with a bend in the middle. We also found that in the walls above the bedroom windows mice had laid in a store of walnuts, whose shells are now as desiccated as anything that was found in Tutankhamun's tomb. How they got the nuts in there remains a mystery, for the walls are two feet thick.

After six weeks of unspeakable dust and increasingly cold draughts, the new window-surrounds are in place. The mullions and drip-moulds, cut from a quarry near Bath, look beautifully sharp and solid. All we lack now are actual windows.

And that episode with the power saw? Ah, yes: needless to say, the one slab of oak that we found in pristine condition protruded into a space needed for the end of a new concrete lintel. Enter yours truly with his Stihl Wood Boss. In the confined space, the noise and fumes were appalling, but I managed to take off six inches of oak without touching either stone or electric cable.

When everything is finished, the house will look infinitely better. The whole structure at one end will be stronger, and we shall sleep more soundly, secure in the knowledge that our chances of dropping into the sitting room at dead of night have been much reduced.

But I have a nasty feeling that Xestobium rufovillosum is, or has been, grinding its teeth in many other places, and that our present upheaval will prove merely the first of several similar earthquakes.