Constructing a Roundhouse
The framework of a roundhouse is constructed from timber. It has been estimated that the typical house required wood from thirty-seven trees. It is often assumed that the main support for the roundhouse roof would be a central pole. However this seems to be the case in only about 3% of investigated roundhouse sites. It is more common to find a hearth at the centre of the building.
But removing the centre pole from a finished roundhouse would be a disaster! The weight of the roof would tend to spread the main rafters outward, lowering the apex and pushing the wall stakes outward until the building collapsed.
The Ring Beam
The solution is to use a constructional device called the ring beam. The roundhouse would, indeed, have a central post for support but only during construction. The main rafters would be attached to one or more circular ring beams high in the building which would also be attached to the central pole.
It is now possible to cut off the central pole below the ring beam. The weight of the roof is now prevented from spreading the rafters and the force is now directed vertically down through the wall stakes.
You can page through the stages of construction by using the arrows on my illustration.
It is often believed that roundhouses typically had wattle-and-daub walls; however daub was generally only used where suitable clay was available. This would not have been the case on the hilltops of the Cheviots.
Most houses leave traces of a 30cm wide depression or ring-groove where the line of the walls would have been. This type of roundhouse would probably have had a solid wall of split timbers.
It is often believed that roundhouses typically had wattle-and-daub walls; however, daub was generally only used where suitable clay was available. This would not have been the case on the hilltops of the Cheviots.
Most houses leave traces of a 30cm wide depression or ring-groove where the line of the walls would have been. This type of roundhouse would probably have had a solid wall of split timbers. Dry-stone walling was also popular, especially after 100 BC. Although wide, many stone walls were rather low and may have been foundations for timber walls. Post-built houses were also common.
A conical roof pitched at 45-55° was thatched with reed or straw, never turf. Experimental archaeology has shown that leaving a hole at the top of the thatch for the smoke from the fire to escape is not as good an idea as it sounds. The fire becomes very difficult to control and runs the risk of setting light to the thatch! Instead, it was more likely that the smoke was simply allowed to filter through the thatch.
