Building a straw bale house on the western side of Islay

[Iceverge]

Straw bales are fine for a fun project in the right climate and you don't care about it as a long term venture. 

 

Try to make a durable house from straw bales and it quickly becomes apparent that they're only useful as an insulation and even then they're full of compromises. Something like blown in cellulose or even chopped straw will be miles better.

 

 

 

 

 

 

[sgt_woulds]

Iceverge, Steamy Tea and others seem to have an aversion to strawbales.  Please could you point to sources for evidence of failure?

 

Correct levels of insulation and airtightness are a matter of design and attention to detail during construction; this applies to any material, natural or unnatural, and self-builders are likely to put more effort into this than 'real' builders.

 

Personally, I'd rather see bales insulating a frame rather than performing two functions, but I'm not aware of any building of either style failing in use that wasn't due to poor detailing or construction.

 

As with traditional cob buildings, wide roof overhangs, decent lime render, and gravel splash back zone, (with free-draining foundations) there is no reason a properly designed and built straw bale building shouldn't stand for hundreds of years in the majority of inland UK or Europe.  E.g.  World’s oldest known timber-frame straw house | EcoCocon | EcoCocon

 

In the OP's location, the addition of a, (ventilated) facing of stone makes sense - although if it were me, I'd be looking at the traditional historic vernacular for highly exposed coastal locations, which tend to favour single-storey earth-sheltered or partially underground structures.  Especially given the more energetic weather likely in the next 100 years.

 

 

 

 

 

 

[saveasteading]

15 minutes ago, sgt_woulds said:

traditional historic vernacular 

Use what is around you?

Stone, peat, reeds, heather, sand, (old barrels ?).

Not my choice now we have options.

[joe90]

Interesting article on the French straw house which proves it can be done but was suprised to see internal plaster was gypsum.

[SteamyTea]

51 minutes ago, sgt_woulds said:

Please could you point to sources for evidence of failure

Not easy to get accurate figures on something that is not about.

 

But this bit from our favourite Wikipedia states:

 

'Between 1896 and 1945, an estimated 70 straw-bale buildings, including houses, farm buildings, churches, schools, offices, and grocery stores had been built in the Sandhills.[9] In 1990, nine surviving bale buildings were reported in Arthur and Logan Counties,[13] including the 1928 Pilgrim Holiness Church in the village of Arthur, which is listed in the National Register of Historic Places.[11]'

 

There are probably the same number of houses local to me, of about the same age.

All of them are still there.

 

One has to be very careful when claiming that historic buildings have intrinsic longevity, they may be the only ones left.

[sgt_woulds]

Without going too deep into history, straw bales were initially used in America by necessity.  It was what was easily available and cheap for people settling in new areas.  Plus there was an embargo on transporting straw and hay by railway so there was much more supply than demand.

 

Once sawmills and brickworks were set up it became easier for more affluent people to build with 'modern' materials.  This set a fashion and pretty soon straw was considered "a poor man's construction method'.  People even demolished their old houses and rebuilt with sticks and bricks when they had more money to improve their personal image.  This had nothing to do with the quality of the original building - which by most reports were warmer and quieter to live in than their replacements.  The remaining straw bale buildings in the USA are a testament to the longevity of natural building materials in the right circumstances - the fact that there are so few remaining has been driven by human foibles, not inherent drawbacks of the build materials.

 

As with cob, adobe, and wattle & Daube buildings, Straw bales built with adequate protection and sympathetic maintenance should last as long - or longer- than their contemporaries made from 'modern' materials.  Some of the oldest buildings in the world are made from earth, not bricks; I've heard claims for some as old as 10,000 years.  In the UK we have Cob and Wattle & Daube buildings dating from the 1600's.

 

I don't think strawbale will ever be a mainstream building product, but it might make sense for a Self-build in the right location.  And it certainly makes sense to use it as infill insulation alongside hemp and woodfibre.  

 

It does seem that the naysayers are basing their opinions on fear of the unknown rather than evidence.

Edited November 8 by sgt_woulds

[sgt_woulds]

18 hours ago, saveasteading said:

Use what is around you?

Stone, peat, reeds, heather, sand, (old barrels ?).

Not my choice now we have options.

 

Straw is just another option.  With any building material, the important thing is how it is used and maintained.  There are thousands of poorly performing buildings being built every day with a multitude of materials.  I doubt that any of them will still be standing in 600 - 6000 years time.  But the odd self-built house, (of whatever material) just might.

[sgt_woulds]

17 hours ago, joe90 said:

Interesting article on the French straw house which proves it can be done but was suprised to see internal plaster was gypsum.

 

Gypsum is more common in France - they even have blocks of it available to build partition walls which I wish we had here.  Contrary to popular belief, Gypsum is vapour open (most materials are to a greater or lesser extent), but not as vapour open as clay or lime.

 

In this building, it was probably working as an internal VCL which could explain the excellent performance and longevity of the building.  

[Iceverge]

20 hours ago, sgt_woulds said:

Iceverge, Steamy Tea and others seem to have an aversion to strawbales.  Please could you point to sources for evidence of failure?

 

 

I've nothing against straw bales.  I spend much of my youth forking them out for bedding, just that they're never the best material to build a house from.

 

We used to have great fun building "houses" in the fields out of them until someone decided we were old enough to pike them onto the trailer or drive the tractor. 

 

However they're very inconsistent in length. Up to 300mm variation in length depending on how much of a lump goes through the baler and gets included in that bale. Similarly they can vary massively in moisture and density simply based on the corner of the field they were harvested from and if the sun was shining when the tractor went past. 

 

These issues are worse with crops from Ayr (200km by road @saveasteading) and other wet climates like Ireland. Straw will be damper, greener and more prone to fungal diseases than drier areas like east Anglia, continental Europe and the great plains.  Small squares are becoming increasingly rare too and largely cater for the horsey market so they'll be trickier to source and you will pay double the rate I do for animal bedding in large squares or rounds. 

 

Then you'll need somewhere to store them in the dry when they're delivered with access for a telehandler or tractor with a specialised grab. Otherwise you'll be lifting them by hand with associated risks of injury and falling and added waiting time for the truck. They'll have to be laid in the dry and covered immediately at any hint of rain or otherwise they'll grow!

 

None of this adds to a cheap build. 

 

Then the practicalities of building with them. 

 

They'll need a metal mesh in the external render to keep birds, mice and espically rats out of your walls. 

 

Insects will be trickier and constant repair of the render for the lifetime of the house will be a reality to keep wasps, bees and woodlice at bay. 

 

Rendering will be multiple more consuming of time than a standard wall and use much dearer materials and more of them too. 

 

Bales are naturally compressible and the building will move throughout it's life and you'll have jamming windows and doors and extra cracks opening up allowing air to leak through the structure with the associated impacts on comfort energy efficiency and building durability. 

 

Then there's the insulative quality of them. They're about 0.05-0.07W/mK depending on what way you lay them. About half as good as already very cheap mineral wool or EPS or blown cellulose. 

 

https://permies.com/t/113626/Straw-Bale-Don

 

The first post I found on Google tells a lot. 

 

 

 

 

 

[Iceverge]

Despite being aware of the risks of straw bales I'm not opposed to anyone doing whatever suits them. It's a free(ish) country. 

 

But to knowingly allow someone to make a potentially ruinous mistake when they asked for opinions and help would play on my conscience.

[sgt_woulds]

Thanks, that's exactly the kind of evidence I was seeking.  I have seen that post before and, from my, (admittedly not top notch these days) memory this is the only such site where I've seen such complaints. 

 

The build referenced seems to use materials finishes that have not been considered in context with the build location.  Earth/clay external render rather than lime, plasterboards internally rather than direct applied plasters.  He moans, but does not answer any of the sensible questions asked by the others.  As such it is not helpful because we learn nothing to ensure better buildings in the future.  The great joy of the natural house-building community is the willingness to try new things and share what works and what doesn't.

 

I think the methods he used were probably poor and more concerned with being cheap than being effective.  I can only speak from the UK context, but cob buildings in areas with burrowing bees etc changed to using Lime render to prevent them digging in.

 

Lime - (or at the very least a lime wash) is also very effective at deterring rodents from chewing through.  They are unlikely to be burrowing into the bales themselves, but living in spaces formed between external finishes and gaps between bales.  Like you, I grew up playing with straw and hay bales - stacked in the traditional manner in barns.  We used to find rodent nests, (and feral kittens) in the straw stacks, but only in the gaps between the bales - they either couldn't chew into the dense straw or wouldn't waste the energy to do so.  In the hay bales they would chew and dig in, but this was probably because they were much easier and full of seeds to eat. 

 

Rodents are opportunists - they make use of what exists and will find easier places to live if the opportunity arises.   That's not to say they couldn't chew their way in, it's just unlikely - more likely they found a gap in the building and exploited it.  Mesh could be a perfectly viable solution in some cases and why not?  It is regularly used for external render works - why would this make the build less viable?  You'd only need it for the first couple of feet unless you have Parakeets in the area; nothing is safe from those little green barstools - but again, design accordingly or buy an airgun.

 

I agree with you regarding the vagaries of weather on straw production and modern methods of farming - but this has nothing to do with the underlying qualities of straw and is about care in the selection and use of materials.   If straw becomes more valuable as a resource to farmers when sold for insulation then they will invest and change methods accordingly.  There certainly should be a premium paid for any material used for building purposes.

 

Cost has nothing to do with this topic though.  This is about building a healthy low-carbon building that is better for people to live in.   It is about the suitability of the material for its location and use case.  Straw won't be the best option in all situations, but it is one of them.

 

A lot of people are prepared to pay more for natural materials and offset this by supplying more of their own effort and time in completing.  Sadly, most buildings with natural materials will cost more since they are not produced on the same scale, (or as heavily subsidised) as unnatural materials.

 

U-value is a matter of providing enough depth but your figures seem wildly pessimistic.  Ecococon 400mm panels using straw compressed at 115 kg/m3, (probably much higher than a standard strung bale) have U-values of 0.15 W/(m2K).  Where are you sourcing these figures?

 

Compression and movement should be assessed and ameliorated in the design and build, but historically a building that can accommodate movement to a certain extent tends to be longer lasting than a rigid one.  Are there any reports of modern bale builds with non-opening windows and doors?

 

 

[sgt_woulds]

To be clear, I'm not sure that structural straw bale is the best solution for the OP's location, but is perfectly viable for infill insulation.  He'd be shipping in insulation anyway, might as well be natural / low(er) carbon stuff.

 

 

[sgt_woulds]

"Bales are naturally compressible and the building will move throughout it's life and you'll have jamming windows and doors and extra cracks opening up allowing air to leak through the structure with the associated impacts on comfort energy efficiency and building durability. "

 

Would you tell someone not to use a green oak frame for the same reason?  

[SteamyTea]

4 hours ago, sgt_woulds said:

healthy low-carbon building that is better for people to live in

Can't comment on how it makes it healthier and better to live in, but farming is anything but low carbon. 

Globally I think it is the third largest polluter if the atmosphere, not looked the the figures recently, but when I did my ResM in Agriculture, the farming community was very reluctant to give any figures about inputs.

Partly why I have a health scpetesim of farming in the UK.

[joe90]

1 minute ago, SteamyTea said:

Can't comment on how it makes it healthier

Natural materials rather than oil based/plastic products spring to mind 

2 minutes ago, SteamyTea said:

Globally I think it is the third largest polluter if the atmosphere

But they don’t farm just to produce straw, it’s a by product which will be produced whether used for building or not.

[SteamyTea]

Just now, joe90 said:

Natural materials rather than oil based/plastic products spring to mind

It soon gets into the mobile phones give people brain tumours, MMR vaccines cause autism and social media caused chlamydia, type debate.

The petrol-chemical industry, and the products associated with it are some of the most tightly regulated there are.

 

It would be interesting to test some straw to see what anti fungal, bacterial and viral sprays are still on them.

Wish I had thought of that when at university, the farmer that took a dislike to me mentioning the pile of dead sheep on his muck pile would have probably punched me.

He got narked when I rounded up his escaped calves the other week.

Blamed me for scaring them.

I shall repeat that.

His escaped calves.

[joe90]

32 minutes ago, SteamyTea said:

It soon gets into the mobile phones give people brain tumours, MMR vaccines cause autism and social media caused chlamydia, type debate.

Oh no it doesn’t (Christmas is coming) I chose where possible not to use plastic or petro chemical insulation and some others here have too. If you have any data on how dangerous natural products are I am sure you will produce a bar chart or graph.

[scottishjohn]

must be plenty of derilict stone buildings to get stone from 

build with that  

maybe like a drystone wall but with mortar and then coat it with render in and out

 and an insulted internal structure how ever you like ,with a cavity 

stone lasts forever

 I am presuming this will be a self build ,so buidling instone you can stop and start as you like and build  as time allows 

Edited November 8 by scottishjohn

[Iceverge]

17 minutes ago, scottishjohn said:

must be plenty of derilict stone buildings to get stone from 

build with that  

maybe like a drystone wall but with mortar and then coat it with render in and out

 and an insulted internal structure how ever you like ,with a cavity 

stone lasts forever

 I am presuming this will be a self build ,so buidling instone you can stop and start as you like and build  as time allows 

 

Stone came to my mind too. Not particularly modern either, even by @SteamyTeas scale. 

 

 

[SteamyTea]

12 hours ago, joe90 said:

If you have any data on how dangerous natural products are I am sure you will produce a bar chart or graph.

I think 'dangerous' is the wrong word.

Having spent an interesting hour looking at some research papers about wheat growing, to get away from manufactured fertilisers, farm yard manure is used.  To increase soil carbon content, biochar is used.

So to grow some wheat, we need to intensively farm some cattle and burn some woodland.

Can we griddle the steak while making the charcoal.

Nice one.

[Onoff]

5 hours ago, SteamyTea said:

To increase soil carbon content, biochar is used.

So to grow some wheat, we need to intensively farm some cattle and burn some woodland.

Can we griddle the steak while making the charcoal.

Nice one.

 

You could just reintroduce bears and let them **** in the woods.

 

I think you can eat bear too. 

[joe90]

5 hours ago, SteamyTea said:

Having spent an interesting hour looking at some research papers about wheat growing, to get away from manufactured fertilisers, farm yard manure is used.  To increase soil carbon content, biochar is used.

So to grow some wheat, we need to intensively farm some cattle and burn some woodland.

Again, the wheat will be grown anyway, the straw is a byproduct.

[scottishjohn]

8 hours ago, joe90 said:

Again, the wheat will be grown anyway, the straw is a byproduct.

and should be used as animal bedding ,not to build houses in a very wet and windy part of the world 

 there is a reason why they built crofters cottages from stone  when they did not have the mechanical means of moving heavy objects easily 2-300 years ago   and it is why alot of them are still standing 

 us it to build an insulating inner wall by  all means  but not as an outer weather shield

Edited November 9 by scottishjohn

[joe90]

1 minute ago, scottishjohn said:

not to build houses in a a very wet and windy part of the world 

I agree, just making the point about Straw being a by product..

[sgt_woulds]

  On 09/11/2024 at 13:23, joe90 said:

Again, the wheat will be grown anyway, the straw is a by product.

and should be used as animal bedding, not to build houses in a very wet and windy part of the world 

 there is a reason why they built crofters cottages from stone  when they did not have the mechanical means of moving heavy objects easily 2-300 years ago   and it is why a lot of them are still standing 

 us it to build an insulating inner wall by  all means  but not as an outer weather shield

 

 

Who said anything about using it as an outer weather shield? This isn't the 3 little pigs 🙂

 

There is plenty of straw for bedding - using the excess for embodied carbon reduction in new homes is an ideal use for the rest.  At the moment - as I understand it - most of the excess is burned to make power, which is nuts.  Back in the day an exciting - but unpleasant - job was to help with burning the stubble fields to create biochar to be ploughed back into the ground.  This is, (rightly) no longer allowed so all straw is now a low-value waste product of producing food crops.  The farmers buy back the 'biochar' from power production at inflated values to perform the same function they used to achieve for free, (barring labour costs and the odd visit from the fire brigade).

 

I agree that using stone for the outer face of the construction makes perfect sense in this location due to the weathering; if quarried or recovered locally it makes for an excellent low-embodied carbon building material.

 

Crofters cottages were often insulated, (inside the stone!) with wool or heather - they made use of what was easily and cheaply available.  [That’s why they built with stone.  If they’d had bricks or abundant timber they would have used that instead]

 

A friend of mine stayed in a cottage on the coast in Norway that was renovated using some of the original wool which was still in perfect condition after 80-odd years.  No reason to assume that any other natural material,(suitably protected) wouldn’t last as well.  I doubt if fibreglass or PIR would be suitable for reuse in the same circumstances.

 

I do agree that we should be looking carefully at the chemicals sprayed on crops that become insulation – but this applies to crops in general.  Industrial farming commits a lot of environmental crimes in terms of chemical use – but compare this to insulation produced by the chemical companies.  Most VOC will dissipate naturally in storage before entering the building and the remainder will be effectively locked away from inhabitants behind the surface finishes.  I’d rather have this slight risk in my home compared to the toxic soup of chemicals used by unnatural insulations.

 

We have hijacked this thread and I don’t want to get into the weeds about the health benefits of natural, breathable, [not the best term but it’s the one people understand] construction materials. 

 

This discussion is about the suitability of straw for the OP’s use and I haven’t seen any logical arguments presented to preclude its use in a properly considered and constructed building in his location.