Iron Age - Moel y Gerddi

This building is based on the layout of a round house from the Moel y Gerddi site in Wales. It is 33ft (10m) in diameter, and built on a double ring of posts.

This build is Mark I. Started by Dr Peter Reynolds, in 1991, at Butser Ancient Farm, after constructing a version at The Welsh Folk Museum at St Fagins, in 1990. The Butser house had stood for ten years half built

Following Peter's death in 2001, the author instigated the house completion, and in the spring of 2002, work began.

Jump to Post Replacement - Jump to Rebuild

Initial Build

This was the house as it had stood for some years.

Half way up the roof was an experimental woven section of purlins. Peter was trying to avoid lashing the hazel rods onto the rafters, and discovered the following difficulties: The higher you go, the less room you have to weave. It takes far more material than individual rings. You cannot get your hands into it if you sew the thatch on.

As work progressed, we returned to the standard method of purlins, i.e. rings.

Daubing was also started as the wall became protected by the thatch.

Thatching progressing rapidly, though as you get further up, more time is spent climbing ladders!
Daub patching on the inside. Sometimes it is quicker to start from scratch, that patch or repair existing work.
Whilst the daub was still damp, the first coat of lime wash is applied to the wall.
Thatch complete, the wall awaiting the final top coat of daub.

The house was finished in time for the farm to open to the public at Easter.

Phil Harding, a long time supporter of the farm, came to officially open the completed house.

After some time, when the daub was completely dry, the coloured paint layer was applied. The red is iron oxide, mixed with the lime wash. There is evidence that iron age houses were painted. Plus, a comment from the Romans who say "...the Britons live in brightly coloured houses..."

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Post Replacement 2008

In 2008, it was discovered that the inner ring of posts were suffering from fungal attack. This was mostly caused by the prolonged exposure to the elements before the completion of the house, and aggravated by the fact that they were ash logs, not oak, and were more prone to rot.

In the archaeology of a number of two ring houses, there is evidence of posts being replaced, so a method had to be devised.

Before the old post could be removed, support for the ring beam was crucial. In the right of this photo, an acroprop can be seen. This is a support pole that can be jacked under the ring to take the weight. This could also have been achieved with a pole and wedges.

With two supports in place, the old post was cut out. For speed, a chainsaw was used.
With a section of post removed, the next job was to extract the remains from the ring beam, and the ground.
By gently wiggling, the post dropped out of the joint in the ring beam.
Still supported by the acroprops, the joint can be seen still intact.
With the post removed, and the bottom part dug out of the ground, measurements were taken. The new post was cut to length, and the tenon created on the top.

The new post was dropped into the hole in the ground, and the tenon lined up and inserted into the ring beam. The post was then repacked around the based. The last job was to remove the acroprops, allowing the ring beam to settle onto the new post.

Having worked out the most efficient way of doing the job, the rest of the inner post were replaced in turn. Each post could be completed in approximately 90mins.

This photo shows how much the fungus had eaten at the structure of the posts. It had reduced the density of the wood to the lightness of balsa!



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Moel y gerddi Mark II- Rebuild 2012

The degeneration of this house continued, and by 2012 the ring beam on top of the inner posts was beginning to fall apart. The most critical part of this were the mortice joints that were holding the ring together on top of the posts. The wall was also starting to collapse as the interior wattle was eaten away by insects, and the daub was tunneled through by rodents. The decision to rebuild was taken, and the house was dismantled, all except the inner ring of posts, as they had been replaced in 2008.

The Rebuild Starts

Replacement lintel in place on top of the inner ring, and new wall posts driven into the ground.

Worth noting, the smoke staining on the top end of the inner posts shows where the smoke ceiling had been in the house.

Inner support ring intact, outer wall woven with hazel.

The difference between the heights, combined with the distance the rings are apart, gives the geometry to create the pitch of the roof, at approximately 45 degrees.

The first of the rafters being slid into place.
Three primary rafters erected. Note the string hanging off a rafter. This enables the center of the house to be accurately positioned.
Continuing the rafter mounting. Not all the rafters have to reach the top. If they did, the apex would be very crowded, and difficult to work in the lack of space.
Rafters nearing completion. Because the rafters are fastened to the wall top, and the lintel on the inner posts. It is not critical that they need to be fastened together at their apex.

First rings of purlins lashed to the rafters.

The thatch is being put on in stepped layers. This is more economical, is quicker to thatch, and is more in line with native roofs in many cultures all over the world.

As the purlins progress upward, the strength of the roof increases, and the cone shape stiffens.

Thatch progressing, and time can be taken to teach the technique that is used at Butser.

The thatch is sewn on with a simple cordage, rather than the modern method of spars and rods.

Thatch complete. Work will begin on daubing the wall. The inside is done first, as this speeds up the drying. The outside is daubed last.
Finished! Oak plank doors hung, and small fence around the outside. This fence is styled after a find at Hengistbury Head, and has proved effective in reducing the amount of thatch pulled by visitors...

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