PCAs busman’s holiday to a timber building in Spain

Back in February this year I was invited to look at a group of timber houses and farm buildings in the Asturias region of Northern Spain. This area of Spain is far removed from the bustle of the Costas. It is a little more temperate but in my view far more beautiful!

You don’t see timber buildings like this everyday!

The most interesting building amongst the complex of timber structures was in a barn (known locally as an ‘Horreo’). According to the present owner it has been on the site for three hundred years. A bit of dendrochronology work would prove this, but lets go with it for now. This short case study looks at some of the interesting features of this fabulous timber building.

 

How this fabulous timber building was built

Close examination shows that the timber building without the use of iron or metal nails of any sort. It is built almost exclusively in chestnut with all the elements hewn from the raw tree by hand.

The basic structure consists of a timber frame built off six conical timber posts. The posts are topped with a circular limestone capping stone (to protect stored roods from rats and other rodents). The building is then formed around a basic rectangular wall plate though the floorboards, wall boards and roof boards are up to 75mm thick and are integral to the structural stability of the building.

The building is functional in every aspect of its design with the result being extremely visually pleasing. The structure seems to sit incredibly lightly on the pillars but in reality, it is incredibly stable.

 

Durability of the chestnut timber the key

Chestnut wood is incredibly durable and despite being in constant ground contact and located in a region with high rainfall, very little decay was detected in the base of the pillars. Some cement mortar has been added around the base of one pillar. This has resulted in a degree of water retention that has given rise to the timber rotting back from the pointing. The timber base of the post has now largely stabilised and the pillar is again stable and effectively rot free!

The roof is covered with traditional terracotta tiles. The loose lay coverings are in very poor condition and this has resulted in long term water ingress.

The significant leak at the apex has caused some minor rot at a high level in the roof timbers. This has not taken any important timbers yet, but a repair must be undertaken soon to prevent deterioration that may require the timbers to be repaired or replaced.

 

An unusual timber finish!

The internal elements are in pretty good shape generally with the standout features being the scale and form and simple durable functionality of the massive wall boards and floor planks.

The peculiar finish to the floor boards inside the barn was hard to understand. I considered the effects of decay and its former use as a store, but could not deduce why the grain of the wood had been raised in the way seen within the picture below. It was only the floors that had aged in this way, but this highly attractive finish was seen across the whole of the floor.

My Spanish is very poor, thankfully however the farmer spoke very basic English. At first he seemed to suggest that Goats has been housed in the barn and that they might have created the texture however, after a great deal of very weird gesturing and unintelligible grunting, I discovered it wasn’t actually Goats. It was actually Rabbits! Apparently, back in the day, rabbits were highly prized for their meat and skins and that this particular ‘Horreo’ had been used to rear rabbits for many decades. It turns out that the highly decorative floor was the work the instinctive burrowing and scratching habits of these animals over many years. Off the back of the fashionable whisky barrow flooring, could there be a market for rabbit finished flooring!!!

 

The shipbuilders that stole the timber!

Though relatively modest by the standards of a barn in the UK, the scale of the building elements are breath-taking. Single planks 75mm thick 4m long and up to 700mm wide are not uncommon. The investment made by the people who it 300 years ago is just astonishing!

I was told that the predominant building timber is Chestnut because the use of Oak was predominantly the reserve of ship builders and as such oak use was banned in building construction. Amazing to think that as this barn was being built the Spanish were using ships built in this region, to assist in the Jacobite rebellion in Scotland.

Timber building not immune to a munch

Wood destroying insects have had a proper go at elements of the building, but happily the majority of the damage seen was superficial. Even where the damage looks bad, investigations suggest that enough structural integrity remains. The fact is however, that as the building is so exposed and easily accessed, it is simple and easy to repair as ‘triggers broom’ (an only fools and horses reference – google it).

 

In conclusion – the simple genius!

The simple genius of a building that uses local materials in a way that delivers form and function as well as durability and aesthetic pleasure is a total joy for a gnarly old sod like me. I hope this structure becomes an old friend and that I and the PCA might play some part in assuring its future for another tree millennia.

 

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