How do I build fitted alcove shelves?

Alcove shelves look like a shelving job and are really a measuring job. No alcove is square, and the difference between a good result and an obvious one is entirely in accommodating that.

Safety

What you'll need

• Timber batten, typically 25 x 38mm, and shelf board
• Drill, detector, spirit level and a saw
• Fixings suited to the wall — usually masonry plugs

Step by step

1. Check what is behind the walls.A detector over every area you intend to drill. Chimney breast alcoves commonly carry cables running vertically from sockets, and a flue may be closer than you think.
2. Measure the alcove at several heights.Width at the top, middle and bottom, and the depth at both sides. It will not be consistent. That single fact determines how the whole job is done.
3. Check whether the walls are plumb.A level held against each side wall. Alcoves usually taper inward or outward, sometimes by 10mm or more over a metre, which is why one-size shelves stick out or leave gaps.
4. Decide the shelf spacing around what goes on them.Books need about 300mm and a deeper shelf at the bottom for larger volumes. Unequal spacing that fits real objects looks better than mathematically even shelves that fit nothing.
5. Mark the batten heights with a long level.Level lines all the way round each alcove at each shelf height. Do not measure up from the floor or down from the ceiling — neither is level, and shelves following them will visibly slope.
6. Cut the back batten to fit tightly.Full width of the alcove at that height. It carries most of the load and it sets the level for the two side battens.
7. Fix the battens into solid material.Masonry plugs and screws into brick where possible. In a stud wall find the studs. A batten into plasterboard alone will pull out under any real weight.
8. Cut the side battens at an angle at the front.A 45 degree cut on the visible end makes the batten far less obtrusive once the shelf is on. It takes seconds and it is what makes the job look considered.
9. Check each batten with a level as you fix it.Every one, individually. A batten fixed slightly out is a shelf that rocks, and it cannot be corrected afterwards without taking it off.
10. Make a template for each shelf.Cardboard or hardboard cut to fit the actual opening. It is much faster than trial-fitting heavy boards and it captures the out-of-square shape exactly.
11. Cut each shelf slightly oversize, then trim.A millimetre or two large, then plane or sand to fit. Taking material off is easy; a shelf cut short leaves a gap you cannot close.
12. Scribe the back edge to the wall.Push the shelf back, run a pencil held against the wall along its length with a small block, then cut to that line. It is how a shelf sits tight against a bowed wall.
13. Add a front edging strip if the board is thin.A strip of timber glued and pinned to the front stiffens the shelf considerably and hides the board's edge. It also makes a thin shelf look substantially heavier.
14. Support long spans in the middle.Anything over about 800mm in a standard board will sag under books. Either use a thicker board, add a front edging, or fit a central support.
15. Fill and decorate before loading.Caulk along the wall junction, fill the pin holes, then paint. Caulk is what makes fitted shelves look built in rather than added.
16. Load the bottom shelves heaviest.Both for stability and because the lowest battens are usually the most securely fixed. It also looks better.

Tips

• Measure every shelf separately. Alcoves taper, and one measurement for all of them never works.
• Mark from a level line, never from the floor or ceiling. Neither is level.
• Caulk the junction between shelf and wall. It is what makes the result look fitted.

Common mistakes

• Cutting all the shelves to one measurement — Alcoves are rarely parallel, often by 10mm or more. Shelves cut to a single width either will not go in or leave visible wedge-shaped gaps.
• Measuring shelf heights up from the floor — Floors are not level, so shelves set from them slope visibly against the ceiling line. Mark a level line and work from that.

If it doesn't work

Questions people ask