Water Reed, Spars and Steel

The coat the public sees is only half the roof. The materials underneath decide how long that coat will last.

Thatching Ireland’s material of choice is water reed — Phragmites australis. The FAQs at thatchingireland.com explain why. Water reed is naturally waterproof. The stem is hollow, the outer cells shed rain, and a well-laid coat of overlapping bundles stops water travelling more than an inch or two into the surface. Gravity then carries weather down a steep pitch and off the eaves.

In ideal conditions water reed can last up to sixty years. In the Irish climate, twenty to thirty years for the main coat is a realistic figure when the roof is thatched properly and the ridge is renewed every eight to twelve years. That is still an outstanding life for a natural, renewable covering.

Quality is not a slogan. Reed quality varies. Nitrate-rich waterways can push reed into long, brittle growth that snaps and fails early. Buying cheap reed to save a week’s cash often costs a decade of roof life. The shop therefore sells water reed in working quantities: 200, 500, 1,500 and 2,500 bundles, delivered on the Irish mainland, unloaded where a trailer can stand, and intended to be stored off the ground under cover.

Hazel spars and scollops. On older roofs, and wherever the new coat is fixed into existing thatch, hazel or willow scallops do the holding. The shop sells straight and twisted spars. Twisted spars behave like staples; straight rods serve as liggers and sways. Have them on site before the weather turns, and drive them with a mallet.

Galvanised bars and screwfixings. On new roofs and many contemporary re-thatch jobs, steel takes the place of some of the hidden timber. The rods and wires disappear five or six inches below the finished face. The roof stays light — thatch weighs about seven pounds per square foot — and it stays put in Irish wind.

Ridge and aftercare. The ridge works hardest and wears first. Block ridges, favoured by Thatching Ireland for the Irish climate, stand proud, shed water, and can be patterned in the thatcher’s own hand. They should be wired. A yearly look-over — a clean-down, a small repair, a dressing of the eaves, a traditional bluestone wash where appropriate — keeps a twenty-year coat from becoming a five-year problem.