John H. Verrill, Executive Director of The Early American Industries Association www.earlyamericanindustries.org, a top-shelf organization promoting and preserving historic trades, crafts, and tools on this side of the pond–and who will be holding their annual meeting at Plimoth Plantation in May, 2013–asked an excellent question on the subject of thatch and ridges:
I am curious about why the ridge would not have had boards affixed to fill the gap between the two halves of the roof since this is a natural point for failure of the thatch. The thatch could then be attached over the ridge in the same manner but with much less chance of failure (?) We don’t have any 17th century roofs to look at but has that point been researched?
All questions regarding historic thatching techniques seem to lead to John Letts and his groundbreaking work published in 1999, Smoke Blackened Thatch:
While there may be no existing thatched roofs from our period to survey in New England, John Letts has done what amounts to thatch-archeology on many roofs in England, from the 14th century onward. The title, Smoke Blackened Thatch–or SBT–refers to the old open English halls which had no chimneys and whose inner thatch layers have been blackened and preserved from decades–even centuries–of smoke and soot from hearths. John’s work has uncovered a ridiculous amount of historic detail–from preserved insects and thatching material (who knew one could thatch with heather, broom, and wood shavings?) to ancient thatching techniques which are little practiced by modern thatchers today. We’ve been fortunate to consult with John on thatching styles which are more appropriate for our early 17th-century site, and his discoveries have greatly influenced our work. From John’s book, here’s an example of both a spar and the blackening of an ancient roof:
And another showing lath being used as a base for the bottom coat of thatch:
The picture above tells a great story: riven (not sawn) oak lath, and pegs (not nails) attaching the lath to the rafters. The oak’s short grain is also blown out at the end of the lath beyond the peg hole. So much exquisite detail, so little time…
Back to the question of a thatched ridge and ways to keep it weatherproof. We didn’t find any direct references to boards at the ridge, but here’s one method of battening down the ridge which John discovered on an old English roof:
Clay! We similarly daubed the ridge of The Howland House with a clay mortar as a direct result of this discovery by John. The mortar is daubed on top of the long rolls which run the length of the ridge. It’s held up beautifully for several years (capped over by more thatch, of course) and while we have centuries to go to catch up to the amazingly preserved Lyndon example, the practice is proving both a functional and historically appropriate method of weatherproofing the ridge.
Smoke Blackened Thatch and John Lett’s ongoing studies continue to inform us on ancient methods and materials. Here’s a link to a chock-a-block and interesting article by John Letts and Keith Quantrill on thatching with ancient varieties of wheat using medieval techniques:
The Riven Word could go in so many directions on this topic alone, but we’ll leave it for now and come back to it when we head to the marshes to cut thatch in a few weeks. No discussion of thatch is complete, however, without a nod to Plimoth Plantation’s own late, great master thatcher Peter Slevin:
ALEX TAKES THE PRETEND PLUNGE
Our intrepid blacksmith Alex (Robert Bartlett) was the groom at a pretend wedding this weekend at Plimoth Plantation, marrying the effervescent Malka (Mary Warren) in a civil ceremony performed by Gov. Bradford. Alex put down his nailing hammer (is that a euphemism or what?) long enough to celebrate at a bride-ale following the wedding. Word on the street has it that Alex dances not unlike Elaine from Seinfeld http://www.youtube.com/watch?v=5xi4O1yi6b0 but hey, it’s the spirit that counts! Huzzah, Goodman and Goodwife!
Fun with Alex’s new hat:
You can view Carolyn’s other creations at: