Rice husks for house insulation

[Francis-udon]

Has anyone used rice husks for insulating their house? Apparently is has excellent insulation properties, costs next to nothing especially up here in the rice farming community, is resistant to water and fungus and doesn't burn very easily. It also has an R-Value of 3 similar to fiberglass.

I was thinking of using it in the wall cavities instead of fiberglass and was wondering if anyone else has tried it. I can't see any reason why it wouldn't be a good idea.

Interesting article about rice husks: http://www.thelaststraw.org/backissues/ ... 0House.pdf

[B52]

Very interesting read but would definately want some more detailed information on existing projects that have used the rice hulls. You would of thought with all the plus points especially cost that this would be in use throughout Asia. I will search around the net and post back anything I find.

Keep us informed if you find some more information.

Cheers,

B52

[jackspratt]

My immediate thought was it's attraction to white ants, particularly where there is structural timber in the roof, or a second floor which contains timber, or paper coated gypsum sheets.

[LoongLee]

Francis-udon and others,,,,,,,, ref the question "has anyone done this yet?". You might find this site with slides interesting: http://www.esrla.com/shotgun/frame.htm

cheers,LL

[eagle]

They have studied that also for Thailand:

www.komatta-chan.jp/eco/pdf/P-092.pdf

Basicly result is that rice hull could be good for insulating, but more studies should be done. Insect attack and fungal growth have to be studied. This was based on study made using boards made from rice hull.

[maaka]

sorry I didnt bother to view the links everyone posted here, just shooting from the hip in my usual way....I am surprised in the first instance that someone needs insulation in a hot country like thailand, but maybe it is sound proofing insulation..

my home is on an island with no infrastructure, no power, water, sewage, so a man makes do with what he has at hand, and over the generations some fellas come up with some niffy ideas when it comes to building houses...one guy went for cardboard egg cartons for insulation, (which also make good sound proofing) as long as they do not come in contact with damp or moisture..

we tried the pink fibreglass bats as we call them, but found over time, years, that they break up, crumble, and then give off a fine dust, not good for the lungs, or ones health, and on top of that, the rats love the fibreglass pink bats..

that stiff white polyseter sheet foam that comes in some packaging, and building stores is great for insulation..it comes in different thicknesses,is easy to cut to shape, not to good in a fire, but for us, if our house catches fire its a goner as the firebriagde is along way away, and we only have 5000l of water on site anyway, hardly enough to contain any such fire from spreading to the surrounding forest..so the idea is not to have a fire in the first place..

as far as rice husks go..I would question the intended life of the material, will it break down over time in the wall , will it soak up moisture, then become a harmful fungi spreading spores into the house environment, and will rats be attracted to it..

[Francis-udon]

Thanks for the replies. I'm still on the fence with this one, it seems like a good idea however as mentioned above it may break down and attract vermin/ants. I don't think there'll be too many problems with mold because it doesn't attract moisture easily.

I'll keep digging around and see what I can find.

I am surprised in the first instance that someone needs insulation in a hot country like thailand, but maybe it is sound proofing insulation

I'm insulating to keep the house cool not warm.

Insulate = To prevent the passage of heat, electricity, or sound into or out of, especially by surrounding with a nonconducting material.

[parrot]

Food for thought:
Have you ever seen a Thai use rice husks as an insulator? Probably not. Perhaps they are aware of its insulative properties.....like strawbale. But if you decide to build using rice husks, you'll surely want someone who knows the ins/outs of building with such a material. If your rice husks (or strawbale) come in contact with any moisture (wicked through the walls/foundation, for example), you'll be SOL.
When the white building blocks first showed up in Thailand, a foreigner we know decided to build a house in Udon using the material. The problem was, back in 2000, the locals craftsmen didn't know how to construct with that material. He ended up with a beautiful house...at the beginning.....the long wide cracks in the walls after the house started to settle.

Thailand's a good place to experiment....but why not try building a small storage shed using your idea......give it a few years, maybe refine the technique a bit.......and if it works, build yourself a house that won't keep you awake at night wondering if termites or mold are eating away at the walls.

[LoongLee]

I would respectfully suggest that those who have raised questions about the various properties of rice hull insulation go to the sites/links posted by francis-udon and myself and take the time to read the studies and bibliographies referenced etc before asking questions that have been answered already.

cheers, LL

[maaka]

righty Ho Loong Lee, I will drag my arse over there and have a decco

[maaka]

well I looked at the OP's link, but your's LL popped up with a security warning and then said I would have to download some thingy in order to open it, so I didnt..sorry..

ok insulation to keep the cool in, now I understand. I dear say if the air con fails, it will keep the heat in too.??? just a question and not a snide remark..we have a straw house here on island, it was a disaster because of our wet climate..all it takes is one nail hole and the whole thing fails..

I trapped rats everyday for 3yrs as a wildlife ranger doing research, and I have seen rats eat almost everything, and if they dont eat it, they will nest in it, so hence my concerns about rats

..I like Parrots idea..try it out on a smaller building

[LoongLee]

maaka" but your's LL popped up with a security warning and then said I would have to download some thingy in order to open it, so I didnt..sorry.."

Ignore the warning about "add on" ,,,, you should still be able to view the slide show,,,,,,,,

Good luck,,,,LL

[Francis-udon]

ok insulation to keep the cool in, now I understand. I dear say if the air con fails, it will keep the heat in too.???

If the house is kept cool and has good ventilation there is no reason why heat will be kept in. Try sitting in a house made with corrugated tin walls and roof or red brick house with no insulation compared to a fully insulated Q-Con house and compare the difference.

In a hot climate insulation is for keeping the heat out and cool air in and limit the need for air-con usage. However if air-con is used in a well insulated room it will keep cooler for longer like a fridge and therefore your air-con wont need to work so hard.

[maaka]

ok Francis I am getting the idea. I am afraid the houses I have lived in Udon and elsewhere in the past, were very old wooden ones where you could see daylight between the floor and wall boards, and could look up in bed and see the underside of the tin roof. The other was concrete cell, and the wall got so hot from the afternoon sun you could almost fry and egg on it, and it took until midnight to cool down, and therefore cool the room down..going by what you say, I dare say it didnt have any insulation, it was just a painted block wall inside and out..

I have never been in a fully insulated Q -Con house to make a comparison....maybe one day when you get your house up and running, and if you throw a house warming party, then maybe you can invite me to see these marvels of the modern world....if the air con works less, then I am on your side..

[philoakley]

Hello francis
I came across your post and wondered if you have gone any further with your project?

I hope to be coming to Thailand early next year perhaps and I have been investigating this particular subject for quite a long time myself.

I would be based in BuriRam

Best regards

Phil

[rjj04]

I was reading the following article and need a little help in understanding a couple of points...
http://esrla.com/pdf/ricehullhouse.pdf

"It is important not to situate a rice hull
house on a concrete slab, since a concrete slab,
in a hot and humid climate, is a magnet for
condensation that demands often times the
unnecessary use of air-conditioning."

"The proposed Rice Hull House is a traditional pier-
and-beam structure situated at least 2 feet above
ground. This greatly reduces termite and flood
risk, and simplifies plumbing and AC
installation. In this way, we also avoid the
horrible problems associated with the
the condensation of water vapor on a concrete
slab. Even without air-conditioning, in the
hot and humid climate of south Louisiana,
condensation on floors, walls and ceilings does
not occur in a rice hull house."

I have never actually noticed condensation on a concrete slab but,
does this mean if you want to fill a double walled cavity with rice husks you should stick something like
styrafoam at the bottom so that the rice husks don't come in contact with the slab?

[Guzzibrewer]

Greetings,

I've built a house here in Japan using rice hulls as insulation. They are great insulation, but do heed the warning to "age" your rice hulls before introducing them into your walls and you might also want to add borax or some other insecticide/ insect inhibitor. We did neither- the rice hulls I was planning to use got wet in a typhoon and mildewed in the storage bags they were in so we were forced to use 'fresh' hulls. We now have a lot of tiny tiny bugs in the walls, that find their way out of the tiny gaps in the internal wall (even though the internal walls were supposed to be air tight as this was to be a passive house.

The bugs don't bite but are a bit of a nuisance. YMMV

GB