Thatching
A short history of thatching
The art of thatching with natural plant materials
has been known in this country since time immemorial. The use of
thatch for roofing emerged from the Bronze Age with thatched
cottages and farm buildings becoming the norm in rural Britain for
over a millennium. It was common practice in those days for
buildings to use lightweight, irregular materials, such as wattle
and daub walls, and cruck beams. These structures could not take the
weight of any heavier roofing material other than thatch. People
would only be able to use what they could source locally: this meant
materials as varied as broom, sedge, flax, grass, and straw were
commonly used.
Every period since the Romans has constructed buildings with
thatched roofs, and examples still exist with at least part of the
base thatch dating from medieval times, when many of the thatching
techniques still in use today were already standard practice. They
are one of the most characteristic sights in our countryside, but
they are practical too – they are warm in Winter and cool in Summer,
but in addition, a thatched roof offers superior sound insulation
properties, which is a real benefit in Diseworth !
It is estimated that the number of thatched buildings in England
decreased from one million in 1800 to about 35,000 by 1960, due
mainly to lower transport costs and new techniques enabling other
materials (such as cheap slate from Wales, or mass produced clay
tiles) to be used, with less skilled labour. The onslaught of
combine harvesters had much to answer for too. With a far shorter
cut, the wheat straw became unusable for anything other than grain
production. Today, there are around 24,000 listed thatched buildings
in the UK, and about 1500 individuals engaged in thatching. Thatch
is also being used on some new builds, so there is something of a
revival in progress.
How does thatch work ?
In thatch, there is no impermeable moisture barrier, so how does it
keep the house dry ? The answer is in the roof pitch. Given a great
enough angle water droplets will run down reed or straw rather than
transfer from one to another. The pitch of the roof, which ideally
should be between 45 and 55 degrees (although shallower pitches are
used over windows and in valleys), forces droplets to run down the
stems of thatch material and run off at the eaves. Below the top
inch or so, a properly constructed and maintained thatched roof
should remain bone dry. This angle is obviously steeper than roofs
with tiles, and this can be a clue to spotting a house that was
formally thatched, but has later been tiled. Examples can be seen
in this detail from a painting of two houses in Hall Gate, both of
which had thatch early in the 20th century, but alas no more:
Detail for A W Redgate oil painting of Hall Gate, c. 1900
Incidentally, since thatched houses do not have gutters and drainpipes to lead away the water, this leads to “eaves-dropping” of the rain, and hence the art of loitering under the eaves to shelter from the water falling, and maybe hearing some juicy gossip through an open window !
Thatching materials and techniques
Thatched roofs in England are usually constructed from water reed, wheat reed or long straw. Water reed is the most durable of all the materials, and is commonly sourced from East European countries. Base thatches, sometimes called layers or coats, usually remain untouched during re-thatching, unless the roof is in really poor condition. Some of this surviving material dates back to medieval times.
Thatch has traditionally been fixed down by being tied to roof members with hand-made rope, by twisted straw sways, spars made from sharpened hazel known as liggers or even by metal crooks or spikes, traditionally made by the local blacksmith.
Water reed thatching is built up like most waterproofing of roofs, starting at the eaves of the roof and the fixing each course overlapping until the apex is reached. The reed face is dress back into position by using a tool called a “leggett”, which is a metal paddle with indentations on its surface.
After the apex is reached the roof must be ridged, because water
reed is not flexible enough to bend, and straw is usually used to
construct the ridge.
Regional variations
The appearance of a roof is affected not only by the choice of
material, but also in the detailing of eaves, dormers, ridges and
surface decoration. Distinct regional styles of thatching are
apparent, and variations may occur from one village to another,
particularly where one style has been adopted by local thatchers and
handed down from one generation to the next.
How long does thatch last ?
This depend on several factors: climate, material used and the skill
of the thatcher, in creating a well-compacted and watertight roof.
Water reed should last about 50 to 60 years, wheat reed about 30 to
40 years, and long straw about 20 to 30 years. Ridges may need to be
replaced every 10 to 15 years, and the body of thatch should also be
maintained and patched if needed.
Replacing the ridge thatch at Primrose Cottage in Hall Gate
At the end of 2008, the ridge thatch at Primrose Cottage was
replaced, having reached the end of its useful life. The old ridge
thatch and its netting cover was stripped off, then water reed
rollers were placed along the top of the main thatch. These were
secured with metal wire ties. This forms a sold core for the ridge.
Bundles of wheat straw were then fixed onto the main roof, to create the sloping part of the ridge.
More bundles of wheat straw were then shaped over the rollers to
form the top part of the ridge that you see, which were fixed in
place using hazel spars.
A block pattern is then cut into the edge of the wheat straw – in this case, it is the personal pattern used by the thatcher.
This can be done with a knife or a pair of shears, and the position
and shape is mostly judged by eye, especially on a complex ridge
such as at Primrose Cottage, with several roof levels.
The main part of the thatch was also scraped off to remove
accumulated moss and debris, and re-dressed with a leggett to form
neat edges.
Finally the ridge was covered in galvanised wire netting, to improve
durability (the wind howls across Hall Field), and to prevent birds
from removing all the new straw for nest material !
Thatch Ornaments
Many theories exist as to why thatch ornaments were placed on the
roof in the past, including to "ward of evil spirits" and also to
"let other tradesman know that the thatcher had a particular problem
getting the money from the owners of the thatched house". There is
no hard evidence to back up these stories! In previous centuries,
hayricks and straw stacks were thatched, and decorated with rick
ornaments which took various forms - a cockerel or a bird, a
cross or a crown. Possible reasons for their use include to show who
the stack belonged to, or to show who had thatched it.
Straw ornaments on the thatch of houses have been recorded as far
back as 1689, but the skill of the thatcher has moved with the
times, and hens, pigs, dragons and many others can now be seen,
although the traditional pheasants and foxes still remain firm
favourites. In the case of the Primrose Cottage fox, the straw is
wired onto an armature and then surrounded by a wire mesh, to
preserve the shape and extend its life.
Metal spikes then fix the ornament to the ridge, to stop it wandering away in the wind.
So next time you walk down Hall Gate, peer up at the roof, think of the skilled craftsmen that still carry on this fine tradition in all weathers, and say good morning to our fox !
Acknowledgements
My grateful thanks go to Gillian Nott of the Guild of Straw
Craftsmen, for information on thatch ornaments. You can read
more about the Guild
here
The thatching at Primrose Cottage was carried out by SM Master
Thatchers of Melbourne, and further examples of their work can be
seen here
Paul Taylor, Primrose Cottage, Diseworth. January 2009.