Are scaffold boards any good for shelves and furniture?

Scaffold board shelving has become a look, and behind the look is a decent structural argument: the boards are made from softwood selected and graded to carry a person and a load, so a shelf made from one sags far less than an 18mm board of the same span. The practical objections are all about weight, moisture and preparation.

What you'll need

• A magnet or metal detector, and pincers
• A belt or orbital sander, or a hand plane
• Heavy-duty brackets or battens rated for the load
• A moisture meter
• Gloves and eye protection

Step by step

1. Know what you are buying.A UK scaffold board is nominally 225mm wide and 38mm thick, in standard lengths, made from graded softwood — usually whitewood — and often with a galvanised steel band nailed round each end to stop them splitting. Used ones have been outdoors, walked on and dropped.
2. Decide between new and used deliberately.New boards are clean, straight and consistent and are not much more expensive than good used ones. Used boards are darker, marked, splashed with cement and paint, and that is the entire reason people buy them. Choose for the look, not because you think used is cheaper.
3. Remove the end bands and every nail.The bands are nailed on and have to come off before you cut. Then check the whole board with a magnet, because used boards routinely have nail stubs, wire and grit driven into them.
4. Expect them to be wet, and dry them first.Boards from a hire yard or a builders merchant are often at outdoor moisture content or worse. Brought straight into a heated house they shrink noticeably in width and can cup. Stack them flat with sticks between layers indoors for several weeks before you cut and fit.
5. Clean the surface before you sand it.Brush the grit off, scrape any cement splashes, and take the first pass with an old belt or a cheap plane blade. The embedded grit in a used board will wreck good abrasives and good irons in minutes.
6. Sand progressively and ease the arrises.Take it as far as the look wants — a light sand keeps the character, a full sand through the grits gives a smooth usable shelf. Round the arrises slightly whatever you do, because a square scaffold board edge splinters.
7. Support them properly.A 38mm board is stiff, but it is also heavy — a metre of it weighs several kilos before you put anything on it. Use brackets rated for the total load, fix into studs or masonry rather than into plasterboard alone, and check the fixing capacity of the wall before the board's own capacity.
8. Finish both faces.Finishing one face only leaves the board absorbing and releasing moisture at different rates on each side, which cups it. Oil, wax or varnish the underside as well, even though nobody will see it.

Tips

• For a cleaner look at the same strength, buy new boards and stain or oil them. Most of what people like about a used scaffold board can be produced on a new one in an afternoon.
• Boards from a hire company are usually stamped or banded with the company's mark. Buying them second-hand is normal, but make sure they are genuinely being sold and not simply on hire somewhere else.
• If the shelf is going up high or is very long, the weight of the board itself becomes a significant part of the load. Weigh one before you specify the brackets.
• The width is fixed at around 225mm, which is deep for a bookshelf and shallow for a desk. Design round it rather than ripping boards down, which throws away most of the stiffness advantage.

Common mistakes

• Fitting them straight from the yard — They shrink, cup and open gaps at every joint as they dry indoors. Several weeks stickered flat in the room is the difference between a shelf that stays put and one that curls.
• Hanging them on light shelf brackets or plasterboard fixings — The board alone is heavy before any load goes on. This is one of the few shelving situations where the shelf material is not the weak link — the wall fixing is.
• Sanding a used board with good abrasives straight away — The embedded grit and cement tear the belt or disc apart within a minute. Brush and scrape first, and use a sacrificial abrasive for the first pass.

Alternatives

• New unbanded scaffold boards: Sold specifically for furniture and shelving, without the end bands, often kiln dried. Cleaner, straighter, no de-nailing, and the same section and stiffness.
• Solid glued-up pine panel: Lighter, flatter, smoother and available in a range of widths and thicknesses, at a similar cost. Less stiff for a given thickness, so check the span.
• 18mm plywood with a solid front lipping: Much lighter, very stable, and a hardwood lipping on the front edge adds both stiffness and a finished appearance. The usual answer when weight matters.

Questions people ask