[GSBN] Straw bale building in tropical areas

Martin Hammer mfhammer at pacbell.net
Wed Jul 12 00:20:21 CDT 2017

Hi Noé (and Bob and all),

I wanted to respond to the first email on the subject, but knew it would
take time to answer properly. Now that my name has been called out . . .

Andy Mueller (on this list) and I and others (incl. Tina Therrien, also on
this list) built the first SB building in Haiti in 2010-11.

We had the same question about building with straw in Haiti that you have
about Benin. Haiti¹s tropical climate includes periods of heavy rain,
including hurricanes, and moderate to high humidity.

To answer the question, we installed 29 moisture sensors in the walls in our
Haiti SB building. Readings over its first three years showed good
performance. Some readings, just before plaster, were over 20%, but over the
first 2-1/2 years almost all readings stabilized between 8-14%. (I¹ve
attached a table of readings from 2010-2013.) Some readings where the bales
are in contact with the gravel bag stem wall, including ones I took at end
of 2013, rose above 20%, but I feel this is a matter of detailing, not

The building also withstood hurricane Matthew in 2016 with only minor repair
needed in an exposed area of plaster at its gable end. However moisture
readings have not been taken since then, and it took a hard but not direct
hit from the powerful hurricane. More about the ³Ti Kay Pay² (small straw
house in Kreyol) can be seen at http://builderswithoutborders.org/ . A
second SB building was constructed in Haiti in 2014 by an Italian
organization but I don¹t have information about its performance.

There are other examples of SB buildings in places of high rainfall and/or
humidity worth looking at.

Sri Lanka: The first SB building in Sri Lanka was constructed in 2005. I¹ve
attached a technical paper, Performance of Straw Bale Houses in Tropical
Climatic Condition, though it is more about its thermal performance than
moisture issues. Here is a link to an article on the handsome building:
http://www.thearchitect.lk/2009/10/a-house-of-straw-2/   Piyal Ganepoal was
the project manager. You might be able to obtain information about the
moisture performance of the building from him via Facebook or Linked-In.

Bali: American architect Jeni Kardinal (copied here) designed and oversaw
the construction (with husband Frank Hyde) of the first SB building in Bali
(Indonesia) in 2014. You can read about and see this beautiful building (and
its beautiful compression mould !) in a Last Straw article at
http://thelaststraw.org/straw-bale-in-bali/ . I¹m not sure how it has
performed regarding moisture, though when I saw Jeni at the 2016 ISBC in New
Zealand I think she indicated so far there were no problems. Maybe she can
offer more if she reads this.

Nepal: Our BWB team plans to build the first straw bale building in Nepal in
October (actually the second if a very temporary building by others is
counted). Nepal has a monsoon season and moderate to high humidity. We have
full confidence straw bale building is suitable in Nepal¹s climate (which
varies considerably with elevation) with normal care, given all I have
stated above. 

I¹ve attached humidity data for the above countries (including Benin) that
is useful to compare. Sri Lanka has the highest average annual average
humidity (79.8%) of these countries, and Bali and and Nepal have the highest
single monthly average (85%). You might want to obtain and compare average
rainfall data also.

I¹ll add that SB buildings have existed for many years in the rainy (winter)
northwest U.S., and humid (summer) climates in the northeast and southeast
U.S. that have performed well, including the famous Burritt Mansion in
Alabama, built in 1938.

The bottom line for me is that high rainfall and high humidity by themselves
will not cause a straw bale building to fail due to moisture. Good
design/detailing, good construction, and reasonable maintenance are what
allow all SB buildings to endure, maybe even indefinitely.  However, if
water enters a wall due to failure of one or more of the three good
practices I just mentioned, a SB building in a climate with high rainfall
and/or high humidity will be at greater risk of damage or failure.

Best regards.

Martin Hammer

Martin Hammer, Architect
Builders Without Borders
Berkeley, CA, USA
510-684-4488 (mobile US)
skype: martinfhammer

From:  Gsbn <gsbn-bounces at sustainablesources.com> on behalf of Bob Theis
<bobtheis3 at gmail.com>
Reply-To:  GSBN <GSBN at SustainableSources.com>
Date:  Tuesday, July 11, 2017 at 1:18 PM
To:  GSBN <GSBN at SustainableSources.com>
Subject:  Re: [GSBN] Straw bale building in tropical areas

While working in Haiti I desperately wanted to test ways to create local
roof insulation,  to  alleviate the infra red oven created by  a tin roof.
My principal concern wasn¹t rot, but critters nesting in it. My first notion
was to mix the local fibers with quicklime, but I didn't have a chance to
field test it. 

But we DO have a 2010 field test of straw bale construction there:  Martin
Hammer, what do you hear from the little cottage?

> On Jul 11, 2017, at 11:49 AM, Derek Stearns Roff <derek at unm.edu> wrote:
> I don¹t have the experience in a very humid, continuously warm tropical
> environment, to propose a natural building solution.  Looking at the current
> local solutions is always a good place to start.  There is also the question
> of what materials are available.  But starting from a place of ignorance about
> the place, if I wanted to include lots of insulation where mold and moisture
> are a big concern, then I would consider blown-in fiberglass (NOT fiberglass
> batts), which has several moisture/mold advantages.
> Best wishes,
> Derek
> Derek Roff
> derek at unm.edu
>> On Jul 11, 2017, at 2:25 PM, Noé Solsona <noe at anarchitecture.org> wrote:
>> Hello ballers,
>> Am still looking for advices on that topic because I have more request for
>> building with bale in hot and humid climate like Guadeloupe, Benin, Sénégal.
>> Many thanks in advance.
>> NoéŠ
>>> Le 29 juin 2017 à 08:17, Noé Solsona <noe at anarchitecture.org> a écrit :
>>> Hello Derek and Bill,
>>> Thanks for your returns, and advice regarding analyzing the moisture effect.
>>> I definitely agree with you Bill, that¹s why I wrote to the GSBN to ask how
>>> to do and if it¹s possible or suitable to build with straw in tropical
>>> climate ? Because I don¹t want to be dependent and risk the failure of the
>>> air conditioning.
>>> So am very wondering if it¹s possible to build with straw ??
>>> Would it be better with light straw ?
>>> Thanks for your advices.
>>> Noé...
>>>> Le 28 juin 2017 à 19:47, Bill Christensen <lists at sustainablesources.com> a
>>>> écrit :
>>>> Hi Noé, et al,
>>>> Over the years I've become a fan of the concept of passive sustainability:
>>>> specifically, what happens to the building when power and mechanical
>>>> systems such as air conditioning fail?
>>>> In the wall described below, you're creating a dependence on the air
>>>> conditioning system, and therefore setting yourself up for potential wall
>>>> failure if the A/C goes down for an extended period, whether due to
>>>> something as simple as financial constraints or as extensive as global
>>>> apocalypse.
>>>> Better to build without such dependencies whenever possible.
>>>> On 6/26/17 4:26 PM, Noé Solsona wrote:
>>>>> But I also hear that it could be possible if we have a vapor block
>>>>> membrane in the outside, and clay plastering in the inside with a good and
>>>>> strong air conditioning system.
>>>>> What do you think ?
>>>> -- 
>>>> Bill Christensen
>>>> http://SustainableSources.com <http://sustainablesources.com/>
>>>> http://LinkedIn.com/in/billc108

On 6/26/17, 2:26 PM, "Gsbn on behalf of Noé Solsona"
<gsbn-bounces at sustainablesources.com on behalf of noe at anarchitecture.org>

> Hello Balers,
> Hope you are all fine in the full season arriving ?
> Back from the ESBG in Venise where I made great contact to go and give courses
> on plastering bales and mechanization of plastering, I got one request for
> building with bales in Benin.
> Did any one of you did such experience or heard of such one in this kind of
> area¹s ?
> I know that I have always heard that we can build with bales all around the
> world where there is straw, but not in tropical places.
> But I also hear that it could be possible if we have a vapor block membrane in
> the outside, and clay plastering in the inside with a good and strong air
> conditioning system.
> What do you think ?
> Thank you very much in advance for your brith advices ;)
> Noé from France
> CalyClay
> Noé Solsona 
> ZI des Monts du Matin
> 100 rue des Lauriers
> 26730 EYMEUX
> France
> P. : +33 (0) 617 421 050
> T. : +33 (0) 482 533 110
> F. : +33 (0) 482 533 111
> noe at calyclay.com
> www.calyclay.com


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: TKPMoistureSensorLog_1.30.13.pdf
Type: application/pdf
Size: 45109 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PerformanceSBHousesTropicalClimate.pdf
Type: application/pdf
Size: 610831 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment-0001.pdf>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: HumidityBenin.png
Type: image/png
Size: 90228 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: HumidityHaiti.png
Type: image/png
Size: 23342 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: HumiditySriLanka.png
Type: image/png
Size: 77717 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: HumidityBali.png
Type: image/png
Size: 102200 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: HumidityNepal.png
Type: image/png
Size: 86850 bytes
Desc: not available
URL: <http://sustainablesources.com/pipermail/gsbn/attachments/20170711/8d6c061c/attachment-0004.png>

More information about the Gsbn mailing list