Cut a shelf to length

Measure, mark and cut a shelf board to a clean, accurate length that fits your space first time.

CS-01Gather your tools and check the shelfGet your tape measure, pencil, combination square, saw, clamps and sandpaper together before you start. Check the shelf board isn't warped or twisted, and decide which face will be seen once fitted — you'll cut with that face up if using a hand saw, to keep splintering on the underside.

1 each · Tape measure

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1 each · Pencil

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1 each · Combination square

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1 each · Fine-tooth hand saw

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2 each · G-clamps

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1 pack · Sandpaper, assorted grit

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CS-02Measure the space three timesMeasure the width of the alcove or space at the top, middle and bottom — walls are rarely perfectly straight, so the three figures often differ by a few mm. Use the smallest measurement so the shelf isn't too tight to fit. Take off a further 2-3mm all round for easy clearance.

CS-03Mark your cut lineMeasure your final length from the square end of the board and mark the point with a pencil. Use the combination square to draw a line straight across the top face, then carry the same line down the front edge and across the underside, so you can follow it from any angle while sawing.

CS-04Protect laminate or melamine finishes before cuttingIf the shelf has a laminate, melamine or veneered surface, stick masking tape along the cut line on both faces to stop the finish chipping as the saw teeth exit. Score along the marked line through the tape with a sharp craft knife for a cleaner edge.

1 roll · Masking tape

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1 each · Craft knife

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CS-05Support and clamp the boardRest the shelf on a workbench or two sawhorses with the cut line overhanging the edge. Clamp it down firmly so it can't shift or vibrate while you saw. If the offcut end is long, support that too, so it doesn't snap off and tear the finished edge partway through the cut.

CS-06Cut along the lineStart the cut with light backward strokes to score a groove, then saw with long, even strokes, staying just on the waste side of your line. Let the saw do the work rather than forcing it — pushing too hard makes it wander off line and splinters the edge.

CS-07Smooth the cut edgePeel off the masking tape. Sand the cut edge first with medium sandpaper, then fine, working in the direction of the cut to remove saw marks and any splinters. Check the edge is square and matches the rest of the shelf's edge profile.

CS-08Check the fitOffer the shelf up to the space. It should slide in without forcing and leave a couple of mm clearance each side. If it's still tight, mark a thin sliver off the long edge, re-cut and sand again rather than forcing it in and marking the walls.

CS-09Finish the cut edge if the core is exposedIf cutting has exposed raw chipboard or MDF core, cover it with an iron-on edging strip matching the shelf, or seal it with a little matching paint or varnish. This stops the edge swelling if it ever gets damp.

1 metre · Iron-on edging strip

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1 each · Matching paint or varnish, small tin

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CS-10Tidy upVacuum sawdust from the work area, clamps and saw. Wipe the shelf down with a dry cloth before fitting or storing it. Keep any decent-sized offcut — it's handy as a spacer or test piece next time.

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