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Thatch Roof Types, Inspection, Maintenance Guide InspectAPedia®  -     Thatch roof inspection, failures, repairs Brief history of types of thatch roofing Books & Articles on Thatch Roof installation, repair, history, & archaeology

Here we describe types of thatch roofing used on buildings, with a brief history of thatch and a focus on contemporary use of this roofing method. This website provides un-biased articles about many common roofing materials, installations, inspection, defects, roofing repairs, and products.

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Thatch Roofing Basics

Traditional thatch roofing was constructed of straw, combed wheat, longstraw, broom, sod, and water reed (Phragmites australis). But other plant materials have been used depending on what was readily available in various parts of the world, including palm leaves and plant fragments.

Thatched roofs were typically installed on steep sloped roof structures in order to shed water rapidly (rather than absorbing it).

Our photo (left) shows a palm leaf thatched roof used on the shelter mounted on Thor Heyerdahl's 1947 Kon Tiki Raft. (The Kon Tiki and its shelter are preserved at the Kon Tiki museum in Oslo, Norway.)

Our page top photo shows another palm thatch roof in Veracruz, Mexico in 1972.

Life Expectancy of Thatch Roofs

Our photos (below) show the exterior and also the interior structure a traditional Mexican thatch roof used at the visitors' center of el Charco, an environmental park in San Miguel de Allende, Guanajuato, Mexico (2004). The interior photo (below right) shows how the thatch roof skylight window was constructed. A closeup of this window seen from outside is provided below in this article.

Water reed thatched roofing can last up to 50 years. Combed wheat reed typically has a life expectancy of 25 - 35 years, and long straw 15 - 25 years. For all of these traditional thatch roof types, re-ridging is needed about every 10 - 15 years.

The life of a thatch roof varies considerably depending on the roof slope (shallower or lower pitch thatched roofs are more likely to leak, absorb water, and have a short life), and on the geographic area where the roofed building is located. The typical slope of a thatched roof structure is 50 degrees. But as we explain next, the slope of the roof structure is not the same as the slope of the thatch itself.

The life of a thatch roof is also significantly affected by the thickness of the thatch, since a thicker thatch results in a less-steep angle of the individual reeds or straws. A less steep reed or straw angle results in a shorter roof life. A 9-15" thickness is recommended for a water reed thatch roof and a 9-12" thatch is recommended for wheat reed and longstraw thatches.

Insulating Value of Thatched Roofs is about R-11 for a typical 9-12" thick thatch.

Books & Articles on Thatch Roof Inspection, Installation, Repair, Maintenance, & History

The books listed below can be found by using the "Roofing" link at the InspectAPedia Bookstore.

• The Complete Guide to Living with Thatch, Michael Billett, Robert Hale (Publisher) 2003, ISBN-13: 978-0709071587. The author guides the reader through the development of thatching, the materials used, and the artistic work that creates the charm and beauty of a thatched roof.
  
  There are extensive chapters giving a host of practical tips for those living in thatched houses, including the advantages and disadvantages, maintenance, fire precautions, costs, insurance, and more. A glossary reveals the many unusual terms used by the thatcher and there is a list of useful addresses for further advice. The Complete Guide to Living with Thatch contains a wealth of practical information and advice for all those who live in or who are contemplating buying a thatched house.
• Thatch and Thatching, Jacqueline Fearne, Shire Library, 2008 ISBN-13: 978-0747805885. The craft of the thatcher probably gives more pleasure to people than any other of our rural crafts. Thatching is a craft most people know nothing about and which is commonly thought to be dying out. In fact, thatchers in all three materials - water reed, long straw and combed wheat reed - now have an assured livelihood after two centuries of uncertainty. This book outlines the history of thatching in Britain from its use as the commonest form of roofing to the present day and explains how the thatcher works with his traditional materials.
• The Archaeology of Scottish Thatch, Timothy G. Holden, Historic Scotland Technical Advice Notes, ISBN-13: 978-1900168496,
  
• "Thatched Roofs - An Introduction," Catherine Lewis, The Building Conservation Directory, 1995
• Thatched roof advisory information for the U.K. is at http://www.thatchingadvisoryservices.co.uk

Quick Comparison of Typical Roof Costs, Life Expectancy, Characteristics

Here is a quick comparison of common roofing materials. Our roofing inspection, diagnosis, repair and installation articles listed at left and below provide roof inspection, roof leak or problem diagnosis, roof installation, and roof repair information as well as details about the factors that affect the life of any roof. We include roof warranty and claim information and links to roofing product sources.

• Asbestos cement roofing shingles, now replaced with fiber cement roof shingles are similar to slate in durability and costs - see slate roofing below.
• Asphalt roofing shingles have an installed cost (including labor) of $100 - $350 per square. (one square covers 100 sq.ft. of roof surface) Asphalt shingles have a typical life expectancy of 15-25 years, with some warranties extending up to 45 years, and asphalt roof shingles typically weigh 225-385 pounds per square.
• Clay tile roofing material and installation labor are more expensive than alternate materials, but the material has a life expectancy of up to 350 years where high quality vitreous tiles are used. Clay tiles are heavy, weighing between 850 and 1,700 pounds per square.
• Wood roofing shingles material cost $150-200 per square, with an installed cost of $130 - $160 / square. Wood shingle roofs have a typical life expectancy of 10-40 years, and weigh 300-400 pounds per square.
• Metal roofing material costs $35 - 250 per square (wide range because of wide range of types of metal roofing), with an installed cost of $35 - $400 / square, a life of 15-40 years or more (a roof kept properly coated can last longer), and weigh 50 - 270 pounds / square. A high end aluminum metal roof may cost $800 - $1000 / square.
• Thatch roofing - typical life 15-25 years. Cost varies by geographic locale, roof pitch, materials.
• Slate roofing has an installed cost of $900 - $1,000 per square, has a life expectancy of 30 - 100 years (or 300 or more in some cases), and weighs 500-1,000 pounds/square. Synthetic slates cost less, typically $700 -$900 per square.
• Membrane roofing such as modified bitumen, rubber, or built up roofing using tar and gravel have a life expectancy of 20 - 40 years, varying significantly depending on materials and workmanship, and may cost $750 to $1000 per square.

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ROOFING INSPECTION & REPAIR
CERTIFICATIONS for ROOFING CONTRACTORS
CHOOSING A ROOFING CONTRACTOR
ASBESTOS CEMENT & FIBER CEMENT ROOFING
ASPHALT ROOF SHINGLES
ATTIC CONDENSATION CAUSE & CURE
BUILT UP ROOFS
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY INSPECTION & REPAIRS
CHOOSING A ROOFING CONTRACTOR
CLAY TILE ROOFING
CONCRETE ROOFING
CORRUGATED ROOFING
ENERGY SAVINGS in BUILDINGS
FIRE RETARDANT PLYWOOD
FLAT ROOF MOISTURE & CONDENSATION
HEAT TAPES & CABLES on Roofs for Ice Dams
INSULATION & VENTILATION INSPECTION & IMPROVEMENT
LOW SLOPE ROOFING MATERIALS
MASONITE WOODRUF FIBERBOARD ROOFING
MEMBRANE & SINGLE PLY ROOFS
METAL ROOFING TYPES
MODIFIED BITUMEN ROOFING
ROOF INSPECTION SAFETY & LIMITS
ROOF VENTILATION SPECIFICATIONS
SLATE ROOF INSPECTION & REPAIRS
SOD ROOFING
SIDING WOOD
STAIN DIAGNOSIS on Building Exteriors
STAIN DIAGNOSIS on Roofs
STANDARDS for ROOFING
STONE ROOFING
THATCH ROOFING
TILE ROOFING
WARRANTIES for ROOF SHINGLES
WOOD SHAKE & SHINGLE ROOFING
WORKMANSHIP & WIND DAMAGE

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