Re: [Strawbale] results of sb houses across europe pls

[Sebastien Hubert <sebastien.hubert@mc2000...>]

Hello,

You are right...

Let's check it with the Mu and Sd value.

If you take the document from the french companions website on this link :
https://docs.google.com/leaf?id=0B-JXZwQKm5TXOTYwMDhlZjEtOGVmNC00YzVhLWJiMWItMjFjMjVmYWVjZWRh&hl=fr
take : Mémento - Construction en paille V1.1.pdf

It's in french ;-)

If we take this document we have (perhaps somebody could confirm the Mu 
values.  It's sometimes difficult to find the right one) :
                           Mu        thickness      Sd
earth render            6          0.05            0.3
agepan                12.5        0.016            0.2
lime                        12        0.02            0.24

The most important value is Sd.  This is the value we have to compare.

We see that with a earth render of 5 cm, the Sd value is 0.3  (5cm of 
earth render is equivalent to 30cm of air)
Sd of agepan is equal to 0.2.  A 16mm agepan plate is more open than a 
5cm earth render.

The document of the companion recommend that Sd of exterieur material 
should be higher than Sd of the interior material or  Sd ext smaller 
than 1.  This is the case.

16mm Agepan is equivalent to 17mm lime render.  I think in pratice the 
lime render is often thicker than the earth render.  It is anyway 
working and give no problem.

I don't think Agepan will be a problem.

By the way the straw bales are able to store some moisture.  And the 
moisture spread all over the straw bales not only in one point.  This 
behavior will help to prevent condensation at the outside even if the 
exterior material is more closed than interior material. 

This is similar to flat roof insulated with cellulose.  Although the 
exterior membrane is completly closed, this is working fine.

All comments are welcome on this really interesting subject.

Cheers

Seb





Henk Van Aelst wrote:
> Ok,
>
> But I mean vapour tightness, because that is something else. Strawbale
> building with plastering is vapour open and air tight. What if vapour
> condenses between Agepan and strawbale? 
>
> Henk
>
> ECOLOGISCH  ARCHITECTENBUREAU  HENK VAN AELST  BVBA
>
> Henk Van Aelst
> TF 0032 / 15 22 51 43
> henk@henkvanaelst...
> Hertstraat 52
> Gsm 0032 473 66 17 92
> www.henkvanaelst.be
> 2590 Berlaar  
> BTW BE 480.118.920  
> www.ecoforum.be   
>
>
>
> -----Oorspronkelijk bericht-----
> Van: strawbale-bounces@amper....muni.cz
> [mailto:strawbale-bounces@amper....muni.cz] Namens Sebastien Hubert
> Verzonden: zondag 5 september 2010 23:38
> Aan: European strawbale building discussions
> Onderwerp: Re: [Strawbale] results of sb houses across europe pls
>
> Hi Henk,
>
> On the outside it will be wood with ventilation between the agepan and 
> the wood.
>
> The earth plastering will be the vapour barier...  this means the 
> renders will need to be really perfect (no crack)...  We really take a 
> lot precautions to reach a really good air tightness.  I also blow 
> cellulose so I know this notion is really important....  We'll do a 
> blowerdoor test.  Just to see if it is efficient...
>
> I think other professionals are using earth renders as air tightness 
> materials.
>
> Cheers
>
> Seb
>
> Henk Van Aelst wrote:
>   
> > Thanks Seb,
> >
> > What do you place on the agepan. 
> >
> > Is there no risk of using a wood,- wool/fibre panel at the outside without
> >     
> a
>   
> > vapour barier at the inside?
> >
> > Henk
> >
> >
> > ECOLOGISCH  ARCHITECTENBUREAU  HENK VAN AELST  BVBA
> >
> > Henk Van Aelst
> > TF 0032 / 15 22 51 43
> > henk@henkvanaelst...
> > Hertstraat 52
> > Gsm 0032 473 66 17 92
> > www.henkvanaelst.be
> > 2590 Berlaar  
> > BTW BE 480.118.920  
> > www.ecoforum.be   
> >
> >
> >
> > -----Oorspronkelijk bericht-----
> > Van: strawbale-bounces@amper....muni.cz
> > [mailto:strawbale-bounces@amper....muni.cz] Namens Sebastien Hubert
> > Verzonden: zondag 5 september 2010 21:49
> > Aan: European strawbale building discussions
> > Onderwerp: Re: [Strawbale] results of sb houses across europe pls
> >
> > Hello,
> >
> > I did respond to this message before but it seems there was a problem...
> >
> > We are using more or less this method except that we don't use OSB at 
> > the inside but earth.
> >
> >  From the outside to the inside :
> > Agepan/double SLS structure-straw/earth
> >
> > You can find some pictures on the Grappaille website (Grappaile is the 
> > promoting strawbale association for the Walloon region) :
> > http://www.grappaille.be/forumgrappaille/viewtopic.php?f=13&t=23&start=90
> >
> > There are also some pictures on my blog : http://blog.paille.be
> >
> > Those websites are only in french sorry ;-)
> >
> > Seb
> > http://www.paille.be
> >
> >
> >
> > Henk Van Aelst wrote:
> >   
> >     
> > > Neale,
> > >
> > > I think google can translate.
> > >
> > > A local Carpenter can make your wooden structure. 
> > > Use an undoubled skelet: for example:
> > > Two SLS / FJI / 2 planches / laminated wood / open joist... It can be pre
> > > fabricated but doesn't need to be. A lot of my do it yourself clients
> > >       
> work
>   
> > > with planches or sls.
> > >
> > > Henk
> > >
> > >
> > > ECOLOGISCH  ARCHITECTENBUREAU  HENK VAN AELST  BVBA
> > >
> > > Henk Van Aelst
> > > TF 0032 / 15 22 51 43
> > > henk@henkvanaelst...
> > > Hertstraat 52
> > > Gsm 0032 473 66 17 92
> > > www.henkvanaelst.be
> > > 2590 Berlaar  
> > > BTW BE 480.118.920  
> > > www.ecoforum.be   
> > >
> > >
> > >
> > > -----Oorspronkelijk bericht-----
> > > Van: strawbale-bounces@amper....muni.cz
> > > [mailto:strawbale-bounces@amper....muni.cz] Namens Neale Brickwood
> > > Verzonden: maandag 12 juli 2010 14:51
> > > Aan: European strawbale building discussions
> > > Onderwerp: Re: [Strawbale] results of sb houses across europe pls
> > >
> > > Thanks Henk, thats very interesting and exactly the system i was  
> > > thinking of. Do you know if there is an english translation website  
> > > with some technical detail re ASBG?
> > >
> > > It would destroy my embodied energy if i had to import the panels to  
> > > the UK but i suppose if the timber is coming from Austria anyway that  
> > > would help
> > >
> > > Regards
> > >
> > > Neale
> > >
> > > neale.brickwood@googlemail...
> > > 07798854867
> > >
> > > www.ikonland.com
> > >
> > > Ikon Land and New Homes Limited
> > > The coach House
> > > 2 hereford Road
> > > Southsea
> > > Portsmouth
> > > PO5 2DH
> > >
> > > On 12 Jul 2010, at 09:01, Henk Van Aelst wrote:
> > >
> > >   
> > >     
> > >       
> > > > Neale
> > > >
> > > > Use a vernished OSB with vapour tape at the inside and a celit 4D or  
> > > > 3D or a
> > > > Agepan DWD at the outside. If you like a little fire protection than  
> > > > use the
> > > > French Dip liming methode before you place the bales and finish the  
> > > > OSB with
> > > > Fermacell.
> > > > Look on www.ecoforum.be on techniques by strawbales to the ASBG  
> > > > Austrian way
> > > > of building.
> > > >
> > > > Good luck
> > > >
> > > > Henk
> > > >
> > > >
> > > > ECOLOGISCH  ARCHITECTENBUREAU  HENK VAN AELST  BVBA
> > > >
> > > > Henk Van Aelst
> > > > TF 0032 / 15 22 51 43
> > > > henk@henkvanaelst...
> > > > Hertstraat 52
> > > > Gsm 0032 473 66 17 92
> > > > www.henkvanaelst.be
> > > > 2590 Berlaar
> > > > BTW BE 480.118.920
> > > > www.ecoforum.be
> > > >
> > > >
> > > >
> > > > -----Oorspronkelijk bericht-----
> > > > Van: strawbale-bounces@amper....muni.cz
> > > > [mailto:strawbale-bounces@amper....muni.cz] Namens Neale Brickwood
> > > > Verzonden: maandag 12 juli 2010 10:17
> > > > Aan: European strawbale building discussions
> > > > Onderwerp: Re: [Strawbale] results of sb houses across europe pls
> > > >
> > > > Thanks dave. Obviously more research to do!!
> > > >
> > > > Neale
> > > > Sent from my iPhone
> > > >
> > > > On 11 Jul 2010, at 22:13, Dave Howorth <dave@howorth....uk> wrote:
> > > >
> > > >     
> > > >       
> > > >         
> > > > > On Sat, 2010-07-10 at 22:35 +0000, Neale Brickwood wrote:
> > > > >
> > > > >       
> > > > >         
> > > > >           
> > > > > > I'm thinking of a dry build using a timber frame to provide the
> > > > > > structure and dry enclosure with the straw being inserted from the
> > > > > > inside (in the dry) timber cladding outside, plasterboard inside. I
> > > > > > know it dosnt stack up with the purist principles but will provide
> > > > > > substantial Co2 savings by omitting brick, block and insulation and
> > > > > > obviously sand and cement.
> > > > > >
> > > > > >
> > > > > > I presume i'd need a breathable vapour barrier between the timber
> > > > > > structure and the cladding which would allow the straw to breathe.  
> > > > > > Do
> > > > > > you know if any one has done any U value calcs for this type of  
> > > > > > build
> > > > > > or do you forsee any problems?
> > > > > >         
> > > > > >           
> > > > > >             
> > > > > Neale,
> > > > >
> > > > > The term "breathable vapour barrier" is an oxymoron. Breathable means
> > > > > "vapour permeable". You probably mean a watertight, airtight barrier.
> > > > >
> > > > > Straw bales are traditionally coated with lime or clay plaster for  
> > > > > two
> > > > > main reasons:
> > > > > -1- it provides fire resistance
> > > > > -2- it provides an airtight barrier that helps the straw function
> > > > > effectively as insulation
> > > > >
> > > > > Gaps between between bales and separate fireproof layers are known to
> > > > > act as chimneys in fires and these can increase the spread of flame.
> > > > >
> > > > > Having said all that, you might want to look at the S-House design.
> > > > >
> > > > > Cheers, Dave
> > > > >
> > > > > ____________________________________________________
> > > > >   European strawbale building discussion list
> > > > >
> > > > > Send all messages to:
> > > > > Strawbale@amper....muni.cz
> > > > >
> > > > > Archives, subscription options, etc:
> > > > > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > > > > ____________________________________________________
> > > > >
> > > > >
> > > > >       
> > > > >         
> > > > >           
> > > > ____________________________________________________
> > > >    European strawbale building discussion list
> > > >
> > > > Send all messages to:
> > > > Strawbale@amper....muni.cz
> > > >
> > > > Archives, subscription options, etc:
> > > > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > > > ____________________________________________________
> > > >
> > > >
> > > > ____________________________________________________
> > > >    European strawbale building discussion list
> > > >
> > > > Send all messages to:
> > > > Strawbale@amper....muni.cz
> > > >
> > > > Archives, subscription options, etc:
> > > > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > > > ____________________________________________________
> > > >
> > > >
> > > >     
> > > >       
> > > >         
> > > ____________________________________________________
> > >     European strawbale building discussion list
> > >
> > > Send all messages to:
> > > Strawbale@amper....muni.cz
> > >
> > > Archives, subscription options, etc:
> > > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > > ____________________________________________________
> > >
> > >
> > > ____________________________________________________
> > >     European strawbale building discussion list
> > >
> > > Send all messages to:
> > > Strawbale@amper....muni.cz
> > >
> > > Archives, subscription options, etc:
> > > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > > ____________________________________________________
> > >
> > >
> > >   
> > >     
> > >       
> > ____________________________________________________
> >     European strawbale building discussion list
> >
> > Send all messages to:
> > Strawbale@amper....muni.cz
> >
> > Archives, subscription options, etc:
> > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > ____________________________________________________
> >
> >
> > ____________________________________________________
> >     European strawbale building discussion list
> >
> > Send all messages to:
> > Strawbale@amper....muni.cz
> >
> > Archives, subscription options, etc:
> > http://amper.ped.muni.cz/mailman/listinfo/strawbale
> > ____________________________________________________
> >
> >
> >   
> >     
> ____________________________________________________
>     European strawbale building discussion list
>
> Send all messages to:
> Strawbale@amper....muni.cz
>
> Archives, subscription options, etc:
> http://amper.ped.muni.cz/mailman/listinfo/strawbale
> ____________________________________________________
>
>
> ____________________________________________________
>     European strawbale building discussion list
>
> Send all messages to:
> Strawbale@amper....muni.cz
>
> Archives, subscription options, etc:
> http://amper.ped.muni.cz/mailman/listinfo/strawbale
> ____________________________________________________
>
>
>