Patching the knees of work trousers that are knelt in every day

row 1 of 4

Deciding between a patch on top and a patch behind

There are two ways to patch a knee, and the choice depends mostly on what the knee is going to do. A patch behind the hole, sewn to the inside of the trouser leg, keeps the outside looking like the original cloth with a window of new fabric showing through. It is tidy, and it is what I would do for trousers that get worn to the pub. A patch on top, sewn over the outside, takes the rubbing itself and protects the old cloth underneath. For somebody who kneels on gravel paths and damp soil, the wear has to land on the patch, so the patch goes on top.

On the first pair I did both. A patch behind the hole, cut big enough to cover the whole thinned area, holds the torn edges down and stops them fraying any further. A second, heavier patch goes on the outside over the first, and that one takes the kneeling. It makes a knee that is stiff for the first week and then softens. She told me later that she had stopped noticing it within a fortnight, which is about what I would expect from heavy cotton that is washed often.

row 2 of 4

Cutting patches from cloth that has already been worn

New canvas is too stiff for a patch on trousers that have been washed a hundred times. The difference means the new cloth does not move with the old, and the seam around the patch becomes the next place to fail. I keep a bag of worn heavy cotton for this, mostly the legs of other work trousers too far gone to save and a canvas shopping bag that split along its bottom seam. Cloth that has already been washed and worn has shrunk as far as it is going to and lost its finish, so it behaves like the fabric it is being sewn onto.

I cut each patch at least three centimetres bigger than the thinned area on every side and round the corners to about the curve of a coin. Square corners on a patch lift, catch on things and fray; rounded ones lie flat. For a knee I cut the patch a little longer than it is wide, because the wear on a kneeling knee spreads down towards the shin more than it spreads sideways. On this pair the finished top patches came out at about fourteen centimetres by eighteen.

row 3 of 4

The treadle for the straight runs, my hands for the rest

Putting a patch on the knee of a trouser leg by machine means working inside a tube, and the tube on a pair of work trousers is narrow. My treadle has a flat bed rather than a free arm, so the only way to reach the knee is to unpick the inside leg seam from the hem to a little above the knee, lay the leg out flat, sew the patch on and close the seam again afterwards. It sounds like more work than it is. The inside leg on these was a single flat-felled seam, and unpicking thirty-five centimetres of it took about as long as a cup of tea.

With the leg flat, the patch goes on with two rows of straight stitching round its turned edge, one a couple of millimetres in from the fold and the second about six millimetres inside the first. The treadle is good at this. It runs slowly enough that I can steer round the curved corners without the cloth running away from me, and it goes through three layers of heavy cotton without complaint, because the drive comes from my feet and my feet do not mind a thick seam.

After the machine work I add rows of hand stitching across the patch, a plain running stitch in a thick cotton thread, spaced about a centimetre apart. The rows quilt the layers together so that they wear as one piece instead of shifting against each other. They also look good, which is not the reason for them but does no harm.

row 4 of 4

What happened to them over the summer

She came back with the first pair at the end of July with soil ground into both knees and the top patch on the left one worn thin at the centre, a darker oval where the cloth had been pressed into the earth for three months. The patch underneath was untouched. That is how it ought to go: the top patch is there to be used up and can be replaced without disturbing anything else. I unpicked it, cut a new one from the same bag, and sewed it on by hand this time, since the rest of the leg was fine and I did not want to open the inside seam twice.

The second pair, the one where the knees were only going, got simple top patches with no backing and running stitch through both layers. They are holding. My guess is that they will want a backing patch by next spring, when the old cloth behind finally gives, but in May the fabric there was sound enough that adding one felt like work for its own sake.