SHELVING & STORAGE

Put up a floating shelf on a lath and plaster wall

Fix a floating shelf securely to a lath and plaster wall by locating solid timber, checking for hidden cables and pipes first.

LP-01Plan the shelf position and mark a level lineDecide the height, then use a spirit level to draw a level pencil line where the top of the shelf will sit. Lath and plaster walls are almost always built on timber studs at roughly 400-450mm centres, so plan your fixing points around that spacing rather than picking spots purely for looks. Mark where you think each fixing needs to go along the line.
1 each · Pencil
1 each · Spirit level (600mm)
1 each · Tape measure
LP-02Protect the area and gather your toolsLay a dust sheet under the work area and move furniture out of the way. Lath and plaster crumbles more easily than plasterboard, so have a dustpan and brush handy for debris as you go. Get your drill, detector and screwdriver bits ready before you start so you're not stopping halfway through.
1 each · Dust sheet
1 each · Cordless drill
1 each · Drill bit set (masonry and wood)
LP-03Work out what is behind the lath and plasterRun a stud detector or a magnet along your marked line, listening for the change from a hollow sound between studs to a solid thud on a stud. Drill a small 3mm test hole in an inconspicuous spot near the skirting first: if it brings out fine timber dust and grips the drill bit, you've hit a timber stud, which is what's almost always behind lath and plaster (pre-1930s builds didn't use metal studwork). If the hole feels loose with no resistance after about 20-25mm, you're between studs and need to shift your fixing point; if you get fine grey metal swarf instead, this wall has been part-rebuilt with a metal stud, and needs different fixings.
1 each · Stud and cable detector
1 each · Small magnet
1 each · 3mm drill bit
LP-04Check for cables and pipes before you drillCables and pipes can run almost anywhere in a wall, not just in the obvious 'safe zones'. Your detector can miss deep cables, ones in metal conduit, or be thrown off by old metal lath nails, so treat every hole as if something could be there until you've proved otherwise. Find your stopcock now, usually under the kitchen sink, and check it turns freely so you can shut off the water fast if you hit a pipe. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling.
LP-05Mark fixing points and drill pilot holesMark each confirmed stud position on your level line. Stick a small piece of masking tape over each mark before drilling to stop the old plaster chipping or cracking. Drill slowly with a wood bit through the plaster and lath (typically 20-25mm total) and on into the stud, aiming for a total hole depth of around 55-60mm so the fixing gets a proper grip in solid timber.
1 roll · Masking tape
1 each · 8mm drill bit
LP-06Choose the right fixing for what you foundIf you landed on a timber stud, use a wood screw or coach screw around 65-75mm long, driven into the centre of the stud, using the 3mm pilot hole as a guide. If the wall is a solid wall with lath fixed to timber battens (a 'studded out' wall) and you've gone deep enough to hit masonry, use a wall plug rated for the masonry with a matching drill bit, and a screw long enough to pass through the plaster, lath and batten gap and still get 30mm or more into the brick or block behind. Never rely on plaster and lath alone for a floating shelf's weight: if you can't reach a stud or masonry at a fixing point, move it rather than trust a light-duty toggle for anything beyond a very small ornament shelf. If you unexpectedly find a metal stud, don't use a plastic plug or ordinary wood screw here, as it will strip straight through 0.5mm steel; you need a self-drilling metal-stud screw or a metal-stud toggle fixing, and even then a metal stud won't safely hold a full floating shelf load without a timber noggin behind it.
4 each · Wood screws 75mm
4 each · Wall plugs (masonry, red)
4 each · Self-drilling metal-stud screws
LP-07Fit the bracket or mounting railScrew the bracket, rail or hidden rods into your marked fixing points, tightening evenly rather than fully tightening one side first. Check with the spirit level as you go, as lath and plaster can sit slightly unevenly and throw the line off. Don't overtighten into old plaster, as it can crack around the fixing.
1 each · Floating shelf bracket kit
LP-08Slide on and level the shelfPush the shelf onto the fitted rods or bracket, tapping gently with a rubber mallet if it's a snug fit. Check it's level along its length and front to back, and adjust the fixings slightly if needed. If your kit has a locking screw underneath, fit it now.
1 each · Rubber mallet
1 each · Floating shelf
LP-09Load test before you trust itPress down firmly on the shelf by hand, then lean on it gradually, checking for movement, cracking sounds from the plaster, or any give at the fixings. If anything shifts or the wall crumbles slightly around a fixing, stop and refit into a confirmed stud position rather than loading it up.
LP-10Tidy up and patch any marksVacuum up plaster dust and debris, and wipe down the wall and floor. Fill any stray test holes with a dab of filler, let it dry, then lightly sand flush. Dispose of packaging and put your tools away.
1 tube · Multi-purpose filler
1 sheet · Fine sandpaper

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