Bajareque Cabin Build – Part 2

The Roof

The rafters and ridge beam come from a local tree called tzajokché (pr. Tza-hock-chay), which needs chemical protection from bugs but is otherwise ideal due its long length, straightness and low density. It’s also local and quickly renewed if the harvest is well managed. Another popular tree for this is lema’, which is even lighter but more prone to insect attack.

Here’s the wall frame and most of the rafters up:

The roof stringers are the same material as the wall straps: Mexican weeping bamboo. However, we treated these ones in a solution of boric acid and borax to keep bugs and mould out. The bamboos in the wall don’t need any chemical protection because they’re encased in mud, which keeps out both insects and moisture – even killing what bugs might have gotten in during the build! I’ve seen 50-year-old houses demolished and the bamboos were as good as new.

So next comes the palm thatch from the coast, about 40 cents per leaf – this truck can carry about 2,500 of them:

And a human can carry about 25 of them! I consider myself tougher than most but I couldn’t carry more than 20. This guy, a 50-year-old father of six, carried more this day than any of the younger guys, many of whom carry building materials as their full-time job. I have utmost respect for their strength, stamina and resilience.

Next comes the thatching, a job best done in cloudy weather as it keeps the palm leaves fresher.

Each palm leaf is tied on using the outer edges of the leaf itself. A top thatcher can attach about 500 leaves a day with a couple of helpers to prep the leaves:

Looking out from under the eaves:

Lunch break – tortillas, chile, beans (yum!) and a 3-litre bottle of Guatemalan cola (yuck!):

And it’s done:

It’ll gradually turn grey over the next month, and it’ll weigh around half what it does at this point too – we had to put in extra bracing to help the rafters cope with the wet weight.

Next comes the walls – in part 3…

 

Bajareque Cabin Build – Part 1

We began building in early 2012 – this is the first of the cabins for The Yoga Forest, a yoga and permaculture retreat centre in San Marcos La Laguna on Lake Atitlan Guatemala.

The view from the cabin-to-be:

Starting the cut:

…and fill:

Excavating for the reinforced concrete foundations:

While reinforced concrete isn’t very natural, it was the only foundation that I and the lead builder felt comfortable with on such a steep slope. I’ve since learnt more about natural foundations and how to work with slopes so the next cabin (immediately next door) will have a lot less concrete and steel in its foundations.

We hit some hard dirt in some of these holes, which at least makes for a solid foundation, if not an easy dig:

One of the concrete footings – 1.75m deep to eliminate the effects of soil creep on such a steep slope:

The foundations complete, for now
– we intend to dig a french drain one day but at this point we just wanted to get the cabin up:

Now we can start with the more natural part of the build!

The structure is bajareque (pronounced ba-ha-reck-kay – read my earlier post about it here). In short, it’s a hardwood post frame, strapped on both sides of each post with many lengths of thin bamboo that are tied on with a fibre extracted from the leaves of the Sisal agave cactus. The void space is then filled with rocks and an earthen mortar, making a very affordable, natural and earthquake-resistant house.

They can be very beautiful too and that’s what we’re planning for this cabin.

Here’s the frame up and the bamboo going up:

This post is getting a bit big now, so read on in Part 2…

A bajareque wall with the Appropriate Technology Collaborative

The Appropriate Technology Collaborative‘s 2012 visit to Guatemala brought 17 volunteers from around Michigan to Lake Atitlán, where they installed a solar electric system to power the computer lab at CECAP‘s vocational training centre in Santa Cruz La Laguna, and built an exterior wall out of bajareque at the nursery school of San Marcos La Laguna.

The problem – a neighbour’s land where the kids would escape!

Before

The solution: a bajareque wall made from hardwood posts, bamboo, rocks, mud, natural rope and elbow grease!

Mixing the mud – many feet make light work.

Applying mud to the wall.

Applying the first layer of earthen plaster with a large wooden trowel.

Project finished! Our local team of natural builders – Juan, Noé, Ventura and Chepe.

And the whole crew – the volunteer team from the Appropriate Technology Collaborative

The whole project was a great success and we’re looking forward to making more such walls in the school and in other public spaces with future ATC volunteer teams. We hope to document the process so that others can copy the technique.

With the help of a pair of longer-term volunteers, this coming week we’ll be putting a small tin roof to keep the rain off, a lime and prickly-pear plaster to defend the bottom of the wall from raindrop splash-damage, and a clay plaster for the rest of it. I shall add photos as it happens.

To see more info and photos on the trip, check out the ATC blog by John Barrie, ATC’s founder and director, and also Tina’s blog.

Bambareque

Bambareque is a fusion of bamboo with the traditional bajareque buildings of the americas.

Bajareque is the wattle and daub of the americas – mud, sticks and stones combined to make simple one- and two-storey buildings. Its most endearing features are its low-cost, renewability, earthquake-resistance and ease of construction.


Cross-section of a bajareque wall from the western highlands of Guatemala

The combination of materials in bambareque is not original, but the name is. I built my first bambareque building – a composting toilet – in 2008, to see if it could add some of the benefits of building with bamboo to the excelent qualities of bajareque. It’s still in great shape and so, due to its use of a cheaper and more renewable resource and having better seismic resistance than traditional wood-framed bajareque, I think it deserves its own name.

In this area (western highlands of Guatemala), bajareque buildings are built by first assembling a frame of hardwood posts. A thin bamboo (Mexican weeping bamboo) is then strapped horizontally onto both sides of the uprights using wet agave fibre ties (aka maguey). Pine needles are draped from the bamboo before filling the cavity with rocks and a mix of mud and pine needles. The mud mix is then applied as an earthen plaster to seal and preserve the organic materials within.

Earthen plaster applied over a bajareque frame

I’ve yet to visit them but I have heard of 500-year-old bajareque buildings in Guatemala that are still standing, although most don’t last that long. Before the 1960’s, most rural dwellings in Guatemala were bajareque, then adobe took over until that too was superseded by reinforced concrete and cinder block. While block and adobe appear more substantial, and are generally more desirable to most rural Guatemalans, bajareque has superior resistance to earthquakes and it’s also considerably cheaper. Ironically, bajareque has seen a revival among wealthier central americans for building their weekend homes, which are often finished to an exceptionally beautiful degree.

A typical bajareque house in El Salvador – note the bamboo rafters.

Replacing the wooden frame in bajareque with bamboo makes it even cheaper and more ecological. The main difference it makes to the building is due to the size of the bamboo – it’s a lot thicker than the hardwood posts they usually use, which are normally three to four inches thick at most (8-10cm), whereas building-grade bamboo is about six inches in diameter (15cm). This creates a much larger cavity, and thus more work to fill it, but it also creates a more insulated wall.

Another difference is that bamboo doesn’t like being buried in the ground, since it’s more vulnerable to humidity, insects and fungal decay than the traditional hardwoods used for bajareque. The bamboo is pre-cured in borax and boric acid but the moisture in the soil will eventually leach that out. My original solution to this problem was to bury it in cement but I’ve since come up with several other lasting solutions:
(1) insert shortened hardwood posts soaked in burnt oil into the base of the bamboo uprights and insert the other end of the stick into the ground;
(2) bury large rocks into the ground (>60cm deep) leaving 10cm proud, glue rebar into them with epoxy, then bend the rebar into a hook, drop the bamboo onto the bar till it sits on the rock, and then fill the bamboo’s base with cement;
(3) tie the bamboo to a reinforced concrete foundation and fill the base cavities with cement.

Four years later, I’m more convinced than ever that bambareque is a sound building method and hope soon to begin building a bambareque community refuge in San Marcos La Laguna, for families whose houses are at risk from from landslides during Guatemala’s heavy rainy season. The venture is funded by The Appropriate Technology Collaborative, who is also bringing a team of volunteers to help build and document the design.

Another project currently underway is a bambareque cabin in The Yoga Forest, a retreat centre and edible forest garden in the hills above San Marcos La Laguna.

For more information on bajareque, check out the World Housing Encyclopedia’s “Vivienda de Bajareque” by Lang, Merlos, Holliday and Lopez.

Building with Big Rocks

I love big rocks. Above all I love their sheer enormousness and immovability, reminding us puny humans how fragile and short-lived we are.

They’re great for building and one of the first structures I ever built was a staircase made from white rock slabs that had been ploughed out of a field. Moving and positioning them is tricky but once they’re in, they’re in and some fifteen years later my stairs haven’t budged an inch. This is my homage to big rocks and the buildings made with them.

We have plenty of big rocks where I live in Guatemala and they’re used a lot in buildings here: in walls, foundations, furniture and sculptures. We built a small amphitheatre for presentations at our centre (La Cambalacha) using rocks weighing up to 6 tonnes :

Moving a medium-sized boulder into place at La Cambalacha
This is one of the smaller ones!

We had up to 20 helpers on the job – a tricky thing to manage as the potential for the inexperienced to crush a finger, toe, hand or limb is significant but, knock on wood, we’ve not had any serious incidents. Add to that the engineering problems of moving these boulders and you can either have a lot of fun or a lot of frustration!

Engineering big rocks is an ancient art form practised the world over, making it all the more surprising that so little is known about how they used to do it. Dynamite, diamond saws and diesel-powered excavators are used nowadays, but check out Wally Wallington’s techniques:

I’m curious to know if this is how Florida’s famed Coral Castle was put together – Edward Leedskalvin (1887-1951) built it in secret over 28 years – or if there’s any truth behind Leonard Nimoy’s speculations here:

These last two buildings involve moving rocks to make buildings, but there is another class of big rock buildings that involves keeping the rocks where they are to form part of the building. Below are some of my favourites.

This is Daniil Sihastrul’s monastic cell in Romania, which he excavated over 11 years in the 15th Century:

Daniil Sihastrul's monastic cell that he excavated from a large rock

One of the many boulder houses in the village of Monsanto, Portugal:

Many of Monsanto's houses are built using large boulders

The Monsanto houses probably inspired this two-storey house, which was built in 1974 between four boulders in the mountains of Fafe in Portugal:

Rocks make this house in Fafe, Portugal

This cave house is one the remains of England’s last troglodyte community, near Kinver Edge, Worcestershire, England:

Derelict Cave House, Worcestershire, England

And here is Matera, where Italy’s last troglodyte community lived, until Italy grew so embarrassed of it that in the 1960’s it was declared a “national disgrace”. The state ordered its evacuation but in 1993 it started becoming a trendy place to set up home and now real estate prices have gone through the roof!

The abandoned and reinhabited town of troglodytes: Matera, southern Italy

Turkey’s Cappadocia region has countless dwellings carved from its rocks, including underground cities that were used as hiding places for early Christians (e.g. Kaymakli):

Goreme, a cave city in Cappadocia, Turkey

Profile map of a cave city Cappadocia, Turkey

In 1998 I spent a month living in a monk’s cave house in Rewalsar, India, which was part of a Tibetan refugee community that lives in some 50 caves and cave-houses nearby the original cave where one of their favourite saints and heroes, Guru Padmasambhava, once made his love nest with the princess of Kangra.

The Tantric master who brought Buddhism to Tibet in the eighth century was born in Pakistan, but he stopped off in Rewalsar on his journey to Tibet to seduce the king’s daughter, Mandarava, who became his consort and travelled with him into the wilds of Tibet. He converted the locals to Buddhism after surviving the king’s attempt to burn him at the stake! My photographs are currently in a box 5,000 miles away in London, so here’s a picture of Padmasambhava in his cave temple.

A statue of Guru Padmasambhava in his old cave at Rewalsar, Himachal Pradesh, India

Here’s one of my latest projects involving a very big rock: a one-room rock and concrete house that we built onto a very large rock indeed – the cliff face. All that cement isn’t very natural I know, but this is where we’re storing the equipment needed to build all the other much more natural cabins, compost toilets and a studio. We’re soon adding a bamboo and palm-thatch second storey, and an outdoor kitchen and dining area.

The Guardianía at Sha'baj, San Marcos La Laguna, Guatemala

Although one saves materials from not having to build one of the walls, the time we saved was lost when we had to engineer solutions to the water that seeps through the walls. I’m glad we had a diamond-tipped cutting disc and one of my favourite tools: my reconditioned Milwaulkee Rotary Hammer, which plunges holes into rocks faster than you’d think possible if you’ve only ever used a normal hammer drill on concrete – click on the image to see the latest version on Amazon.

Milwaulkee Rotary Hammer eats rocks for breakfast - click to view on Amazon (opens in new tab)

Not that I like breaking open or plunging holes into age-old rocks, but sometimes there is little option. According to Hinduism, spirits often identify themselves with rocks and mistakenly believe that they are the actual rock itself, and so masons will either say a small prayer before working on a rock or even, in the case of a larger rock, call for a puja or ceremony to release the spirit within. The priest informs the spirit of its metaphysical confusion, thus liberating it from the rock. Only then can work begin!

On that note, I’ll leave you with a photo of the Ellora cave temples in Maharashtra, India, which I visited in 2003. Built over a 300-year period, the 34 caves were excavated by competing Buddhist, Hindu and Jain sculptors. This is the Hindu Kailash Temple.

Kailash Temple, Ellora Caves, Maharashtra, India

I’d love to hear of any other interesting big rock buildings – just add a comment with the link, thank you.