The Thatched Roof Process

Early Thatched Roofs

• Long before recorded history people contrived ways to protect themselves from wind, rain and sun. In the beginning they sheltered in caves, or sought protection from the weather under leafy tree limbs or stretched animal hides. But with the first house came the problem of covering the top of it. Thatch was devised from whatever materials were available. Vegetation such as reeds, tall grasses and sedge was cut, tied into bundles and lashed to beams across the top of the dwelling to form a roof. In the beginning the results were crude and only nominally effective, but thatching was to become a fine art. Other techniques developed. According to Richard Graves, author of Grave Bushcraft Books, there are as many methods of thatching as there are thatching materials.

Layering the Thatch

• The most common method is to sew or lash the thatch bundles to battens running from eaves to ridge pole. These are thin strips of wood laid between the rafters. Green reeds or grasses tend to shrink. Allow them to dry before bundling. If bundled too soon, lashing or stitching loosens and the thatch is more prone to leaks. If installed correctly a thatch roof won't leak. Rain only penetrates slightly into the thatch. Most runs off and drips from one level of thatch to the next until its final drop from the eave to the ground. Thatch is installed in overlapping layers beginning at the corner of the eave and moving upward to the ridgepole. On top of that, more layers are added to bring the thickness of the thatch up to about 12 inches in depth.

Cutting, Bundling and Tying Thatch

• In developing countries thatching materials are cut, gathered and bundled by hand in much the same way as in the distant past. Now much of the thatch is machine cut, but according to CAD Architect information, some true craftsmen of the trade believe hand-cut thatch is superior because hand-cutting is less damaging to the ends of the reeds or grasses. After cutting and loosely bundling, the bundles are shaken and combed to remove any loose materials. Then they are tightly tied in smaller bundles. In the past, the thatch bundles were laid butt down on the roof and fastened to the battens with flexible vines or fibers. Now twine, galvanized wire or even vinyl strips are used to "sew" the thatch to the battens.

Palms for Thatching

• In tropical countries palm fronds are used for thatching. Although warm weather prevails, rain is frequent and heavy in the tropics. Palm is an excellent watershed. Although thatching in the United States hasn't gained in popularity to the extent it has in the UK and other parts of the world today, palm is often used in Florida for summer shelters and beach house roofs. Faux thatch is available from dealers for people who like the look but are wary of natural materials because of possible rodent infestation or fire. Tight thatch discourages rodents and is no more likely to catch fire than wooden shingles. If it does, it is harder to extinguish but with today's fire retardants, according to NFU Mutual, even insurance companies have relaxed their prejudices.