Diary of a Straw Bale Building Project

DENEYS FARM - BUILDING OUR STRAW BALE HOUSE IN THE FREE STATE

Introduction

In January 2013, Thelma and I started work on an ambitious project that we have been planning for a couple of years - to build a Straw bale house on the farm in the Free State. 

After I retired from Jozi Housing in mid 2012, we "sold up" in Johannesburg and moved to the family farm "Deneys" near Reitz in the rolling hills of the eastern Free State.  We needed to build our own place on the farm separate from the family farm house (pictured below), which is used by our kids and grandchildren, and their friends and their kids as a weekend escape from the pressures of living in Johannesburg.

I don't know exactly where the idea originated, but somehow the challenge of building a straw bale house captured our imagination in early 2011 and has just stuck. It's been done overseas for hundreds of years, and there are already over 50 straw bale houses in South Africa. There's even been a straw bale house featured on Grand Designs (we missed this episode). We spent the next two years researching the idea, and visiting various sites where people have already built straw bale houses, or are in the process of building straw bale houses. We needed to figure out whether we were brave enough to embark on what appears to be part building science and part black art. None of what we learnt frightened us too much and so we decided "what the hell - let's go for it".
 

Our family and friends are mostly fascinated and enthusiastic about the idea. Others, when hearing what we are doing, think we are nuts.  But almost everyone has said "We'd love to know how you get on"

So this blog has been set up with a number of objectives. (a) to record the progress, the excitement, the trials and tribulations of this unusual project. (b) to act as a diary of the build that we can look back on in years to come, and (c) to serve as inspiration, a warning, and a source of information based on our experiences that may help anyone else contemplating a similar build.

The intention is to post pictures and entries every two or three days or when we reach major milestones in the build. The latest posts will appear at the top (immediately after this introduction) and the oldest at the bottom. This is to enable you to see what's new without having to scroll through all the old stuff.

 We hope you enjoy the journey with us.

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LATEST UPDATE

 24th August 2013

 Wow its been a long time since the last blog update. The time just seems to have flown by.  Where to start on the progress since 30th June.

The first half of July was focused on getting the second coat of plaster finished both inside and outside the house. This enabled us to smooth out some of the lumps and bumps that were in the first coat - and to create the soft rounded corners around the doors and windows that are a distinctive feature of straw bale houses. We then had to keep the whole house draped in plastic to allow the plaster to dry and cure slowly. This plastic wrapping stayed on for nearly three weeks which was very frustrating because we were dying to see what the house looked like with the plaster complete.
 

When we were finally able to remove the plastic drapes, the house emerged like a beautiful butterfly from its cocoon - and we weren't disappointed. The plaster was a beautiful colour like expensive Italian stucco - thanks to the influence of the cow dung. What's also very satisfying is that the house is now almost the same colour as the brown Free State winter veld in which it sits. One of our design objectives was to have the house blend in and become part of the landscape.  

The next major stage was putting in the insulation in the roof and the ceilings. We had already put in the polystyrene sheets under the concrete floor slab and the double glazed windows and doors. The ceiling is the final insulating barrier to keep heat in and the cold out.

 

The combination of getting the ceiling in and painted white plus removing the black plastic covering on the outside walls transformed the inside of the house which is now flooded with light, and warmth.  









In the last week of July we started on the last major stage of "wet-work" - laying all the cement screeds. We started with the front and back porches -edging these with re-cycled slate tiles from the roof of Nick & Louise's house in Greenside (they recently replaced their slate roof with corrugated iron). After the porches we then geared up to lay the screeds inside the house. This had two major complications. Firstly, we had decided (after a succession of minus 6 degree nights) that as an added precaution we would install under-floor heating when we laid the final screed in the open-plan lounge/dining room/kitchen area. In keeping with the eco-friendly concept of this house, this U/F heating will be provided by solar-heated hot water circulated through a maze of pipes embedded in the final screed. We tracked down the right kind of piping and laid nearly 300 metres of this pipe before covering this with the cement screed. With the pipes installed we'll come back and connect the solar panels and pump to circulate the hot water next year before winter arrives.

The second major screed challenge was getting the colour of the screed right. This was obviously one of the key elements in Thel's decor plan for the house. Her brief was that the floor should be a deep brown - a tone similar to the wooden parquet tiles (also re-cycled), which will be laid in the adjoining study and the bedroom. Using different mixes of brown, red and yellow oxide pigment I laid a series of test panels to try and get the desired final result. Unlike mixing paint - it takes 2-3 days for the cement screed to dry and for the final colour to emerge. The pic shows some of the first test panels which produced the wrong colour. This exercise was complicated by the fact that Thel was away overseas at this crucial stage and I was sending her photos of the test panels by e-mail to get her views. We finally found a formula that appeared to give the right result and with fingers crossed laid the screed. To my great relief, when Thel arrived back at the farm earlier this week she was happy with the final colour. Phew!!.
 

The last exercise before we sent the builders on two weeks leave till the end of August was to cast the concrete kitchen counter tops. This involved building a forest of timber supports and putting in a grid of reinforcing steel. I also had to build forms to allow us to drop in the gas hob and the under counter sink afterwards.
 










The August break has been absolute heaven so far. We spent 4 days in Johannesburg after Thel arrived back from overseas, and didn't have to worry about what was going on back at the building site. Since getting back to the farm we have been able to have leisurely starts to the days, and I have been able to spend hours in my workshop. Mainly getting all my woodworking equipment geared up for the next phase of the build which will involve lots of carpentry - building bedroom and kitchen cupboards, shutters, bookshelves etc etc.

What is a bonus is that the weather seems to be turning - spring is definitely on the way. There are tinges of green here and there, and we've had three new calves born in the last two weeks.  The evenings have been beautiful, and the bitter cold has abated. However, last year we had a black frost in October so there are still some cold spells to come.

So we'll enjoy another week of freedom and then its back to building work again for the last 6-8 week push to completion - so we can move in. Seems unreal even to think about it - but the end is in sight.

'Til next Time 

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PREVIOUS UPDATES


30th June 2013
 
I can't believe it - the year is half gone, and we're still building. It seems like only a few weeks ago that we started building (the first blog post was 16th January) - and at the same time it seems like we've been building forever.  
Since the last update the double glazing team from Natal came up and installed all the windows and fold back doors. other than the front door, which I'm building myself, and the glass door off the bathroom - the house is weather proof. We just have to ensure that no-one sticks a scaffolding plank through one of the double glazed panels.
The building team has installed the roof over the bedroom, study and front porch - which we had to hold off until the plastering started. Most of the team has been finishing off the cobbing on the straw bales, which has taken much longer than anticipated. But while the cobbing was being finished we have been focused on plastering. For most of the month, Norman Ngwenya, our senior builder, was back in Joburg, and this meant that we only had one plastering team - so progress was slow. Thankfully, Norman came back at the beginning of this week and the plastering pace over the last few days has doubled. 
 

 

It took us a few days to learn how to get the plaster to the right consistency, but once we had this sorted this process has gone without a hitch. Fortunately we have and endless supply of both the clay and the cow dung - and both of which are free. As the plaster dries it changes to a mottled almost white colour which has a great natural patina. Once we have finished this coat we have to start all over again and apply a second plaster coat to ensure that the straw bales are properly protected from the elements.

The picture shows the large metal tank that we use to brew up the "cow dung" slurry before it is added to the lime plaster mix. Although it looks somewhat unappetising - it is virtually odourless. However, for a few days after the plastering of the main wall inside the house was completed, the interior had a decidedly "agricultural" atmosphere. As the plaster has dried this has disappeared.

One of the challenges of working with this lime/cow dung plaster is the need to allow the plaster to dry and cure slowly. In fact the plaster will only be fully cured in 6 -12 months. To achieve this we have to cover each days completed plaster work with plastic sheeting. And each day the plaster is damped down again and covered up again. Now that we've nearly finished the exterior walls the whole house is virtually wrapped in plastic. This creates some fun and games when the Free State wind starts pumping - as it has quite frequently recently. Like hoisting a jib sail on the foredeck of a yacht in a good off shore blow. Makes me quite nostalgic.

Prior to the plastering of each wall, I have had install top and bottom window sills for every one of the 21 windows in the house. The purpose of these sills is to direct rain water running down the walls and windows out and away from the straw bales. The sills are cut out of fibre cement board with an angle grinder, and have to fit snugly above and below each window. The cutting is very dusty and the sills are installed using Fisher foam which one blasts out of an oversize aerosol can. I have managed to get the stuff in my hair, on my glasses, and down my shirt sleeve - and once the gooey foam sticks it doesn't come off easily. After 10 days work I have only three windows left which can't be soon enough.

In the middle of the month Thel installed her free style panelling on the wall of the dining room - opposite the stone wall. She rounded up a whole lot of scrap wood around the farmyard and working on a ladder right up to the 4 metre high ceiling she pieced together all these different shapes and sizes to produce a really striking textured wall with different textures and colours - the overall effect is really great. It will be a real conversation piece.

For most of the month of June we have had real winter here - with most early morning temperatures between -2 and -5 degrees - and a few nights down as low as -9 - which was properly cold. Despite lots of lagging all the pipes are frozen each morning and no running water until around 9am -10am. One morning I came across a beautiful ice sculpture at the back of one of the building - where the water from a leaking pipe (cracked by ice) had splashed on the ground and formed this amazing landscape of miniature ice sculptures.

So the major tasks for July will be to finish the second plaster coat, install the ceilings and insulation and lay the flooring - and to stay warm

"Til next time.



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2nd June 2013

Its been 3 weeks since the last update and this update will be in a slightly different format. I've had requests from some friends for more pictures, and for more technical detail. So hopefully this layout will meet these requests.  

This weekend we reached another major milestone in that we've finished the building of the straw bale walls. We had just started when I sent out the last update. Progress on this phase has been slower than anticipated. The erecting of the bales goes quite quickly but the cobbing of the walls after the bales are installed has taken much longer than we planned. Cobbing which involves manually plugging a mixture of clay and straw to the bales is vital for

three reasons. Firstly, cobbing fills in the gaps between the bales and around  the poles and the window boxes to create an even surface. In a well cobbed wall the shape of the bales should be barely visible. Secondly, cobbing compacts the clay surface of the bales and creates a really hard face to the wall. A well cobbed wall shouldn't develop any cracks as it dries.  Thirdly, cobbing provides a key to the surface which aids the adhesion of the plaster that is 

applied as the seal and protection for the bales. The beauty about working with clay is that when we've had to go back and re-cob an area that is dry - one simply has to sprinkle water on the surface and it becomes pliable again. What is remarkable is how solid and strong the walls become after the clay surface has dried for three or four days.

 

Even though the bales are all in - there is still a few days cobbing work to be done before I'll be satisfied that the walls are ready for plastering. Whilst I'm happy that the walls should have an "organic" look to them and the corners won't be quite square, old building habits die hard and I don't want them to be too organic.

 

Thel has spent two of the last three weeks painting all the window frames before they were installed. This marathon job involved sanding and painting 21 separate window frames with two coats each. It was extremely fiddly and painstaking work and something that I wouldn't have had the patience to do. Because of the need to get the window frames painted and installed before the team arrived to put in the double glazing (which happens this week) - Thel was painting until late on several nights. This painting job is done and nearly all the window frames are in - and they look great. The battleship-grey colour (Plascon call it "Dusk of Day") looks great and will contrast nicely with the off-white walls once they're painted.

While the bales were being finished, our electrician Lawrence Kaseke came down to put in the electrical wiring in the walls and install the plug boxes and switches before we start plastering. It is astonishing how much wiring is required for a building with relatively few rooms and not a lot of lights and plugs. He is an old style tradesman that takes pride in his work and the results show it.  

A reminder of how eco-friendly this method if building is, is demonstrated by the green sprouts that have emerged in several places in the walls - where wheat seeds that came with the straw have germinated in the wet clay. We feel hesitant about covering them up with plaster. Hopefully they won't persist and push their way through the plaster. Time will tell.

 

 

 

 

 

 

 

 

 

 

Finally, all the family came down for the weekend and Thel used the opportunity to organise a small ceremony to give them some some attachment to the house - like launching a ship with a bottle of champers on the bow. She asked everyone to write down their wish for the house on a small piece of paper and these were pushed into various cobbing holes in the walls. These will be plastered in for perpetuity (or as long as the bales last). It is really wonderful how enthusiastic and supportive the Barnes tribe have been about this build. Numerous friends have also been keen to find out how we’re going.  There is going to have to be a biiiig party when we finish.

‘Til next time   

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12th May 2013

It's hard to believe that its been nearly a month since the last update. What's that about "times flies when you're having fun"?  Within days after the last update the roof went on. This suddenly turned the skeleton into something resembling a house. We were now able to get a real sense of the space inside. With the roof on, the house has also asserted its presence on the landscape.

We then started building and installing boxes to take the double-glazed windows and doors. These are being built in Pietermaritzburg, and are normally installed by the supplier. But being 450 kms away from the factory has forced a change of plan. By installing the boxes first we can go ahead and build the straw bale walls around the window apertures.  We have installed the 23 boxes and tomorrow I go down to Natal with a trailer to bring back the frames without the glass. I'll install the frames in the boxes and Gus the window builder will come up at the end of the month with a team to install the special glass - which is part that requires real expertise.

On Wednesday 8th May at 3:40pm we installed the first straw bale and we are now officially building a strawbale house. The first panel with about 20 bales is a bit ropey - but the second and third panels are much better. Hopefully, within the next couple of days we should get it right.

By the end of the month we should have all the bales in and then we start with the other black art in this process - putting on the plaster made with lime and cow-dung. Our builders can't believe that we aren't using any cement for either the bales or the plaster. This will be a further test of our mantra for this project which is "making it up as we go along". 

Winter has really arrived in the Free State and we are having below-zero temperatures almost every night. This is a timely re-inforcement of one the reasons we decided to build a straw bale house.

 'til next time.

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 PREVIOUS UPDATES

14th April 2013

I'm happy to report that we have made real progress since the last update. The timber frame is complete. The building team have shaped, sanded, lapped, drilled and bolted a total of 68 gum poles. Last week we put in all the verticals, the ring beam and the rafters for the front roof which will cover the bedroom, the study and the front stoep. This week we were working on the main roof. The last step took place on Friday when we used a crane to hoist the 11 metre long main rafters into place - each of them weighing about 200 kilos. As each of rafters was lowered onto the frame, I was listening anxiously for any sounds of cracking, or groaning from the supporting structure - but much to my relief everything held fast. Yesterday and this morning was spent making minor adjustment to levels and bolting these monsters into place.

The building now looks like the skeleton of some giant dinosaur. For the first time Thel and I have been able to get a real sense of what the house will look like - both outside and inside and we've spent four or five hours over the last couple of days walking around under the rafters and getting our heads around the reality of the space. The next big step will happen over the next 10 days when the corrugated iron roof goes on - we start with the purlins first thing tomorrow. Over the last week we have also brought in a backhoe to dig out a large area on the south side of the house, and to dig the holes for the septic tank, and for the underground grey water storage tank. This will enable us to re-cycle our grey water (baths, showers, and kitchen sink) and use this water in the loos and in the garden.

Over the last couple of weeks Thel has made some major breakthroughs on her side. A few weeks ago she started cheese making and has produced some really great tasting Parmesan type cheese a la Deneys Farm. There are a couple of other batches maturing - one a feta type crumbly cheese and another which will hopefully turn into a cheddar type cheese. She has also been experimenting with different bread recipes to find one that produces a real farm loaf. After trying a couple of different recipes she produced a "Pane Rustico" which looked and tasted fantastic - especially straight out the oven. This is going to be our daily bread. While the autumn weather has reduced production in her vegetable garden, she is still harvesting large quantities of tomatoes.

Every building project has numerous day-to-day frustrations and by the end of the day I am worn out by the need to constantly make decisions. Our project probably has more of this "decision overload" because we are not following  any normal building processes. We are making it up as we go along. One of real antidotes to these frustrations is our evening walk along the farm roads through the veld. A real sense of peace descends as the sun goes down and one can feel one's frustrations melt away. We are really lucky to be living and building in this special place. A couple of days ago we got a special sunset which "put the bow on the show".
'Til next time.  

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2nd April 2013 

Its been a long couple of weeks since the last update. Work on the build has advanced frustratingly slowly. The team has been concentrating on erecting the timber frame which will carry all the load of the roof timbers, (those massive 11 meter long gum poles featured in a previous update), and the corrugated iron roof sheets. It also has to act as the anchor for all the timber boxes that take the windows. So it has to be strong and rigid.

Cutting the lap joints and bolting the ring beams in place required painstaking accuracy to ensure the joints and mounting points were tight and strong. As the photo shows the top ring beam at the front is rather high and getting the poles up to the 4,2 meter height required lots of heavy lifting.

We managed to get almost all the ring beams in place and bolted up securely before the Easter long weekend, when we brought them back to Joburg for a break. The builders, as well as Thel and I needed a few days off after working for 7 days a week for the month of March. In the week before Easter we had some very welcome rain. It hadn't rained a drop since the previous update on 17th March, and the farm was very dry. We were quite pleased to have a couple of hours one afternoon rained out.

We've had a very relaxing long weekend - doing very little. On Thursday early it will be back to the farm and the building site. The first objective will be to get the large 11 metre long rafters lifted into place with a crane from Reitz, and then to get the roof sheets on. I will be building the boxes to take the double glazed window frames that will be coming from Durban towards the end of the month. Our timetable is now about 2 - 3 weeks behind schedule. Hopefully we can claw back some of the lost time over the next few weeks.


17th March
 

Since the last update we have made good progress in some areas and poor progress in others. The stonework has moved ahead steadily and after finishing the plinth around the perimeter,Thel and her stone team started on the large wall separating the lounge from the bedroom wing. This is slow and painstaking work with every stone having to be selected by hand and fitted into place. However the finished effect is great, and its very satisfying to know that all the stone has been sourced on the farm - either from the old sheep kraal, or down at the river.  

The front of the wall closest to the camera gives one an idea of the single pitch roof and the height (4,3m) of the almost double volume of the main part of the house which is the open plan lounge and dining room. When our friend Robert Brewster, who is a stone expert, saw the previous blog post he e-mailed to say that the proper description of the type of stonework we are doing is "snecked rubble". Now that's a great word to store away for the next Scrabble game. We have also nearly finished all the other internal walls - just a couple more courses and this part of the build will be complete. The part that is behind schedule is the timber frame. I only started trimming gum poles to fit into the steel supports today and getting the first pole right took hours. Hopefully once I get the technique right, the remaining poles will go much quicker.

 

One of the causes of the delay on the poles was that I took Friday off to attend a major auction at a farm near Tweeling, about 30 kms away. I've never been to one of these before and wanted to see how the whole thing works. On auction were 5000 sheep, 300 cattle, half a dozen vintage cars, and masses of farm equipment from tractors to hay balers, to feed troughs and old gates. There were well over a hundred of the local farmers present, many bidding for the cattle and sheep, and the whole event had rather a festive feel - like a country show. Although tempted by many items on sale, much to Thel's relief all I came away with was a very old and dilapidated draw bar trailer (that's a type with a wheel on each corner), and assorted farm gates. Both of these lots were bargains - although the trailer is going to need a lot of repair work, and will be a real test of my amateurish welding skills.  

 

So the next big push will be to get the timber frame erected. The target is to complete this before the Easter weekend - which will be a challenge. After that the corrugated iron roof gets installed, and then......... we start with the straw bales.

 

 

 

7th March

Things are now starting to get much more interesting. Thel has spent a number of days full time on the building site getting the stonework on the plinth going and ensuring that it has the right look. She wants to have the same look as the dry stone walls one sees on the west coast of Ireland, and which we also found in a very old stone sheep kraal on the farm when we arrived here. In fact all the stone in this new wall is re-cycled from part of the old farm house and from a part of the sheep kraal that was about to collapse. This is the first part of the build that will give the house the look of a converted farm shed and fit in with the stonework of the main farmhouse and other sheds on the farm. One of the builders, Nqobile, has shown a real flair for fitting the stones together and has produced most of the wall pictured above on his own. This is a win as we have still have a lot of stonework to do. 

The internal walls are also progressing well and one can now get a real feel for what some of the internal spaces will be like when finished. At this stage I am starting to feel the impact of "decision overload" which anyone who has done a major building project will know about. There are just a myriad of minutae that have to be worried about and decisions made - in order to reduce the number of "oops" later on. Very much a case of "the devil is in the detail" 

 

The latest major event has been the arrival (from Natal) at 8 pm last night of 10 tons of gum poles. These will form the load bearing structure of the building and the rafters for the roof. My Gawd but the roof rafters are massive. Each of them 11 metres long and weighing upwards of 100 kilos. Looking at them two thoughts occurred to me. The first is that we had better make sure the support structure is really strong - it has to carry 14 of them. The second thought was how on earth are we going to get these rafters up into position. We will have to organise some kind of crane. Human brawn alone won't do it.
The work of building the load bearing structure is next. That is going to be very interesting and very hard work.  

1st March 2013

While I was extracting pics for the blog I came across this photo which I took when Thelma and I went for an evening walk a couple of weeks ago just before the last big rain that we had. Gives meaning to the phrase "Big sky country". One of the things that make one appreciate living on the farm.






28th February 2013
In the two weeks since the last update a lot has happened. We've had a week's break in Jhburg, getting a little bit of civilisation after three weeks of rural solitude. Just before we left the casting of the slab was completed. This was a major undertaking involving the laying of the normal damp proof coursing, but also 50mm thick sheets of poly styrene insulation, and the steel weld mesh reinforcing. While we were away, Nqobile finished building the brickwork portion of the plinth on which the straw bales are laid. We have started on the internal walls and will concrete in today the steel tubes which support the gum poles that will make up the structural, load bearing timber frame.
The weather has been extremely hot and no rain for the past two weeks so it was a great relief to have 6mm of rain, which has also cooled things down. As the picture shows, it looks like we'll get more rain today.


12th February 2013
Major milestone - the straw bales are delivered - 650 of them. Now we're really committed. Until now we could have chickened out and just carried on building a normal house with bricks - but now there's no turning back. Quite scary. Watching the bales being off-loaded my reaction was " Are we really going to build a house out of these???" No wonder one of the companies building straw bale houses in Australia is called "Huff & Puff Construction"


8th February 2013

The foundations are in. A lot more time checking dimensions and re-checking them - particularly to make sure the corners are square. Mindful of the old adage "Measure twice - cut once". Fortunately the site is fairly level so there is very little adjustment needed.




1st February 2013

The shed is finished and waiting for the bales to arrive. We've made our first milestone on schedule. Let's hope that we can keep this up through the rest of the build. Now we move on to the real stuff. We have spent two days laying out the foundations for the main house. There has been some debate about the final position of the house and this resulted in moving it 3 metres further east, and adding 700 mm to the east/west axis of the house. This is one of the joys of building on a farm where space is not a factor. We have been very lucky in that it rained quite a bit before we started digging foundation trenches. The ground was rock hard before we started, but manageable when the builders started digging in earnest.


21st January 2013

Good progress. The shed is nearly finished. Only the sheets on the sides still to go on.Building in the middle of Free State summer is very hot. Thank goodness for the afternoon shade from the gum trees alongside. This is a simple structure but it serves the purpose of "getting our eye in" and used to the processes of measuring, aligning, and making sure everything is square. It also highlights the lead times involved in getting materials on site and having to plan much more carefully - there isn't a hardware store just around the corner


16th  January 2013

This week we broke ground and started building the shed which will become our carport/garage next to the new house. This was the first priority as our straw bales were due to be delivered at the end of January, and we have to have a place to store these and keep them dry and safe from Free State thunderstorms. The house will be built behind where the tractor is parked, positioned to give us views down the valley towards the Liebenbergsvlei river