Elm

Also called: english elm, wych elm, dutch elm, ulmus

Elm is a tough hardwood with an irregular, often wavy grain, prized less for looks than for standing up to conditions that rot other timbers.

Species and appearance

Common English elm (Ulmus campestris) is reddish-brown with pale sapwood, a very irregular grain and many small knots. The Dutch variety shows a straighter grain than ordinary elm, and when freshly cut its sapwood is clearly distinct in colour from the heartwood beneath, though it dries out quickly once cut. Wych elm dulls cutting edges only moderately and machines and works well by hand; air-dried, it bends well by steam, though green stock will crack or warp and any knots must be avoided for a good bend. Rock elm, the American Ulmus racemosa, was rated by Hasluck (1907) as highly valued and close in character to English elm, "though not, perhaps, quite so tough as that timber." Elm's latewood, the denser wood laid down later in the growing season, characteristically forms wavy bands across the pores, a pattern so reliably found in the genus that wood anatomists took the term "ulmiform" from Ulmus itself.

A wheelwright's account, and a disagreement over durability

Sturt (1923), a wheelwright describing his own shop, recalled elm as "pale-brown and butter-coloured" beside oak and white-grained ash, and recorded two problems in converting it: elm reliably dries "curly", with a ripple running across the grain from end to end of a board, and a six-inch thickness of elm "would not make six one-inch boards" when resawn. Accounts also differ on what keeps elm sound. Jones (1920) held that it is durable if kept continuously dry or continuously wet, and cited hollowed elm logs once used as water pipes, the Rialto at Venice reportedly built on twelve thousand elm piles, and elm still in use for pumps as of the 1920s. Hasluck (1907), writing of American elm, English elm, beech and alder together, held instead that these woods resist decay only if kept fully submerged in water, and not otherwise. Elm also shrinks a measurable fraction of its width in seasoning, though the figure recorded for this has not survived legibly.

Uses

Elm has long gone into cooperage, saddlery, axe handles, and wagon and boat building, and in America it also served for chair-making, railway sleepers, and door and window sills. Jones (1920) rated it, once imported into England for coachbuilding, wheel-making and boat-building, as "one of the best timbers for bending." Historically it also supplied slack cooperage, casks not required to hold liquid, along with crates, baskets, boxes, furniture, farm equipment, caskets and burial boxes, and parts for vehicles; today elm lumber and veneer go mostly into furniture and decorative panelling. Wych elm and maple are named among the rough-barked timbers used for craft sticks, alongside the smooth-barked birch and wild cherry, and one example piece, a low-back Windsor chair, pairs a wych elm seat with the rest of the chair in oak. In structural carpentry, an old rule for an unbolted scarf joint, where two timbers are lapped and jointed end to end, in oak, ash or elm beams sets the joint's length at six times the beam's depth.