The detector went solid at 1.1 metres up, about 120 mm from the corner of the left-hand alcove, and Matt took his hand off the wall as if it had bitten him. It was Saturday morning, 9 May, we had a drill, three lengths of pine and thirty-four cookbooks, and the wall was telling us not to start there.
The alcoves either side of the front-room chimney breast have been empty since we moved in, apart from a pile of cables and a box that said "misc". Since we uncovered the tiled fireplace last summer, the alcoves looked like they were waiting. I weighed the cookbooks on the bathroom scales to see what we were asking of the wall: 31 kg, which is more than Matt expected and less than I'd feared.
Finding what's in the wall
Our walls are brick with about 20 mm of hard 1930s plaster on top, and the odd surprise buried in it. We borrowed Kev's detector, which finds metal and live cables, and the first rule was that it isn't gospel. The instructions say so on the front. So we added two more habits. Cables usually run straight up or straight along from sockets, switches and light fittings, so we kept well away from those lines. And we stayed away from corners and anything within 150 mm of a socket.
The right-hand alcove had a cable running up from the socket at the skirting, which we marked in pencil and kept well clear of. The left alcove had that solid pipe signal, which turned out to be a heating pipe that feeds the front bedroom radiator, chased into the plaster at some point since the 1990s. We'd never have guessed it was there. I wrote "PIPE" in capitals on the wall and drew an arrow. The batten on that side had to cross the pipe's line, so we kept every screw at least 60 mm either side of it.
There was also a hollow patch low down in the right alcove. You find it by tapping with a knuckle until the sound changes from a knock to a drum. Plaster that's come away from the brick can't hold a screw, so the screws there had to go through it into the brick behind. We wore dust masks and glasses for the drilling, because brick dust is nasty.
The fixings
The shelves sit on 25 mm square battens along the back and both sides of each alcove, with an 18 mm pine board on top, screwed down through the board into the battens. We drilled every hole with a 6 mm masonry bit through the plaster and into the brick, put in 6 mm plugs and used 80 mm screws. With the batten and plaster taking up about 45 mm, that leaves roughly 35 mm biting into brick. Screws into the plaster alone would be decoration.
Matt set the first batten with the 1.2 m spirit level and checked it against the second. "Perfect," he said. "Now do the other seventeen." Each alcove has three shelves, about 85 cm wide and 23 cm deep. The cookbooks went on the bottom shelf and the middle one, and the top shelf stays light, with candles and a plant. Once the books were on, I put the level back on the bottom board. The bubble hadn't moved.
The hole in the wrong place
The first hole I marked in the right alcove was 12 mm below the pencil line, because I said "there" while my thumb was over the mark. Matt drilled where I pointed. We spotted it at once, filled the hole with filler, and moved on. Luckily the batten is 25 mm tall, so it covers the patch, and nobody can see it. A hole you can't see is still a hole in the wrong place. I know where it is.
The whole thing cost £64: pine shelving board £38, battening £9, plugs and screws £8 and Danish oil £9. The oil went on Tuesday evening and the books went up this morning, about an hour before I started writing. No pipes were harmed. The one we found is on a photo on my phone, labelled in capitals.
