Rebecca Trewin
Why reclaimed floorboards make brilliant floating shelves
Old floorboards are a gift for anyone who likes making things. They are usually 18–22mm thick and 120–200mm wide, which is exactly the sort of proportions you want for a shelf. Because they have been seasoning in a house for decades, they are far less likely to twist or cup than fresh timber from a yard. The grain is tight, the colour is deep, and every knot and nail hole tells a story. You are also saving a bit of history from the skip, which is never a bad thing.
Before you commit, check each board carefully. Look for rot, woodworm (small flight holes and fine dust), and splits. Run a magnet along the length to find old nails — a single cut nail will ruin a saw blade in seconds. Treat any worm with a suitable wood preserver and let it dry fully.
Measuring, choosing and preparing your board
Decide on your shelf length and depth. For a typical alcove or chimney breast, a length of 900–1200mm and a depth of 150–200mm works well. Mark your cut line with a combination square, not a tape measure alone, so the ends are truly square. Clamp the board to trestles and cut on the waste side of the line with a fine-tooth saw or a circular saw fitted with a fine blade.
If the board is badly cupped, you can flatten one face with a hand plane or belt sander, but do not overdo it. A little undulation is part of the charm. Remove any remaining nails with pincers, or punch them through with a nail set and fill the holes later.
Cutting and sanding for a clean, safe finish
Sanding is where a reclaimed shelf starts to look intentional rather than rough. Begin with 80-grit paper to shift dirt, old finish and splinters. Move up to 120-grit, then finish with 180-grit. Always sand with the grain. If the board has old paint, scrape it first and wear a mask — pre-1960s paint can contain lead. Ease the front edges with a 2mm chamfer or a light radius. This is not just for looks; it prevents splinters and makes the shelf feel good in the hand. Wipe off all dust with a tack cloth before finishing.
How a floating shelf hides its fixings
A true floating shelf has no visible brackets. There are two reliable DIY methods. The first is a hidden internal batten: you fix a timber batten to the wall, then hollow out the back of the shelf so it slides over the batten like a sleeve. The second is a concealed metal rod bracket, which slots into holes drilled into the back of the shelf. For reclaimed floorboards, the batten method is usually easier and stronger.
Cut a batten around 50mm x 50mm, slightly shorter than the shelf. Fix it to the wall dead level. Then rout or chisel a matching channel in the back of the shelf, allowing 1–2mm clearance so it slides on without binding. Once fitted, secure the shelf to the batten with screws driven from underneath, or a bead of strong grab adhesive plus a couple of hidden screws. Predrill to avoid splitting old timber.
Fixing safely to brick or plaster walls
This is the part where safety matters. A shelf loaded with books or jars can easily weigh 15–20kg. You must fix into a solid substrate, not just plasterboard.
- Brick or block: Use a masonry drill bit (6–8mm) and good quality wall plugs. Drill 10mm deeper than the plug. Avoid mortar joints if you can — bricks hold far better. For heavy loads, use a chemical anchor or a sleeve anchor.
- Plasterboard on studs: Find the studs with a detector and fix the batten directly into them. If there are no studs where you need them, cut away a section of plasterboard and fit a timber pattress to the masonry behind.
- Dot and dab: Common in modern UK homes. The plasterboard is stuck to the blockwork with adhesive blobs. Drill through into the blockwork and use long screws and plugs, or fit a pattress as above.
Always check for hidden pipes and cables with a detector before drilling. Use a spirit level to get the batten true in both directions. If you are unsure about your wall type or the load, ask a qualified tradesperson.
Finishing and fitting the shelf
Finish the timber before you fit it. For a natural look, use a hard wax oil or Danish oil — two or three coats, rubbing back with fine wire wool between coats. For a painted shelf, a water-based eggshell or chalk paint followed by wax works beautifully. Avoid heavy polyurethane varnish if you want a subtle, tactile finish; it can look plastic on old wood. Fill any nail holes with wax filler matched to the timber.
Slide the shelf onto the batten. If it is tight, sand the channel a little. Once happy, secure it with a couple of screws up through the batten, or a bead of grab adhesive. Wipe away any excess. Stand back and admire your work. Reclaimed timber shelves suit cottages, Victorian terraces and modern flats alike, and they cost little more than a few hours of your time.
