[Strawbale] Strawbale Digest, Vol 17, Issue 6
Michel Couvreux
transmin at sonic.net
Wed Nov 14 12:30:42 EST 2007
Erica,
I would suggest that you also consider the use of Natural Hydraulic Lime or
NHL.
Even if it is more expensive, it is as easy to use as a cement stucco,
simply because it is hydraulic (sets under water), with guaranteed
performance, contrary to a Hydrated lime which may be tricky to install and
without any guaranty for performance. Plus, in your climate, the Hydrated
lime may be too weak to last.
Mark was mentioning the use of lime in wet climate in UK or Europe. These
lime were more or less hydraulic, and some of them lasted for centuries.
The use of NHL is very common in Europe, due to its qualities and
performances.
You may find some usefull information on www.limes.us and for strawbale
application on http://www.limes.us/con-plaster-straw.html
I hope this helps that it is a worthwhile to look into the use of this NHL.
Michel
Michel Couvreux
TransMineral USA, Inc.
Showroom:
TransMineral USA, Inc.
2105 S. McDowell Ext. Suite D
Petaluma, CA 94954
Mail:
TransMineral USA, Inc.
201 Purrington Road
Petaluma, CA 94952
707-769-0661
707-769-0352 Fax
transmin at sonic.net
www.limes.us
----- Original Message -----
From: <strawbale-request at listserv.repp.org>
To: <strawbale at listserv.repp.org>
Sent: Wednesday, November 14, 2007 9:00 AM
Subject: Strawbale Digest, Vol 17, Issue 6
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> Today's Topics:
>
> 1. stucco outside, earthen plaster inside? (Erica Konrad)
> 2. Re: stucco outside, earthen plaster inside?
> (Mark BP / Low Energy Design Ltd)
> 3. Re: stucco outside, earthen plaster inside? (Erica Konrad)
> 4. Re: stucco outside, earthen plaster inside?
> (Mark BP / Low Energy Design Ltd)
> 5. Re: Frost Heave (was re: Too Late to Plaster?) (Speireag Alden)
> 6. Re: stucco outside, earthen plaster inside? (Speireag Alden)
> 7. Re: ahh, finally have slab done (Raftercat5 at aol.com)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 13 Nov 2007 10:26:37 -0800
> From: "Erica Konrad" <strawbale at netidea.com>
> Subject: [Strawbale] stucco outside, earthen plaster inside?
> To: "SB REPP" <Strawbale at listserv.repp.org>
> Cc: SB Yahoos <sb-r-us at yahoogroups.com>
> Message-ID: <4035C981AD68413BBA0830C2EBABDDA5 at FamilyPC>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Dear all - I was wondering if there is any problem with plastering the
> interior of my strawbale home with earthen plaster and the exterior with
> stucco. We are in British Columbia in a pretty wet, wind exposed site and
> I
> would like to cover the exterior with stucco for this reason (won't be
> doing
> the stucco until the spring, but will work on the interior plaster (with
> heat) over the winter). Does is matter if both sides are different
> finishes
> in terms of moisture?
> Thanks in advance,
> Erica
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 13 Nov 2007 13:23:29 -0600
> From: Mark BP / Low Energy Design Ltd <mark at lowenergydesign.ca>
> Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
> To: Erica Konrad <strawbale at netidea.com>
> Cc: SB Yahoos <sb-r-us at yahoogroups.com>, SB REPP
> <Strawbale at listserv.repp.org>
> Message-ID: <4739F9B1.30306 at lowenergydesign.ca>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Erica -
>
> If you're in one of the humid bits of BC, I would stongly advise not to
> use stucco at all. I did a hygrothermal modelling exercise on this for
> my PhD a few years back, and found that for conditions in Cardiff (a bit
> damper than the weather data I've seen for coastal BC, but not by much)
> there is a real risk of bale moisture content reaching the sort of
> levels that mould can grow at if the plaster is Portland cement based.
> There is no such problem with clay or lime plaster.
>
> The reason for this is the low permeability to vapour flow of Portland
> cement based plasters. Moisture that enters the wall can't get out
> quickly enough. This is particularly a problem with the configuration
> you suggest - relatively easy for moisture to get in though
> high-permeability clay plaster (in a heating climate the flow of
> moisture is from inside to outside for the vast majority of the time),
> relatively difficult for it to get out again to the outside through the
> stucco.
>
> The results of my calculations were, of course, based on a whole series
> of assumptions, as is any research in building physics. If you were to
> keep your house at lower average humidity levels than I fed into the
> model, you might be OK - but to do so involves greater energy
> consumption (by maintaining higher temperatures throughout and/or
> increasing average ventilation rates).
>
> Lime render, if applied correctly, is more than adequate for coping with
> driving rain. The British Isles are littered with mediaeval castles
> that used it (and it wasn't rain penetration that turned most of them
> into ruins....) - in many cases you can see the continued success of
> traditional plaster recipes not only against driving rain but also
> against salt spray. It has been used successfully for centuries on cob
> buildings in the wet and windy west of England and in wet and windy
> Wales. So far as I can see, the reason that so many Canadian sb
> builders use stucco has nothing to do with superior performance and
> everything to do with familiarity, availability, lack of skills &
> training (though it's actually not that difficult), etc. European sb
> builders are, on the whole, a lot less inclined to use stucco.
>
> Your proposed course of action would work perfectly well here in SK.
> But it's not a risk I would ever want to take in coastal BC.
>
> atb
> Mark Bigland-Pritchard
>
>
>
> Erica Konrad wrote:
>
>>Dear all - I was wondering if there is any problem with plastering the
>>interior of my strawbale home with earthen plaster and the exterior with
>>stucco. We are in British Columbia in a pretty wet, wind exposed site and
>>I
>>would like to cover the exterior with stucco for this reason (won't be
>>doing
>>the stucco until the spring, but will work on the interior plaster (with
>>heat) over the winter). Does is matter if both sides are different
>>finishes
>>in terms of moisture?
>>Thanks in advance,
>>Erica
>>
>>
>>
>>_______________________________________________
>>Strawbale mailing list
>>Strawbale at listserv.repp.org
>>http://listserv.repp.org/mailman/listinfo/strawbale_listserv.repp.org
>>
>>
>>
>>
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 13 Nov 2007 19:33:12 -0800
> From: "Erica Konrad" <strawbale at netidea.com>
> Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
> To: <mark at lowenergydesign.com>
> Cc: SB Yahoos <sb-r-us at yahoogroups.com>, SB REPP
> <Strawbale at listserv.repp.org>
> Message-ID: <8A688055CCCF4CF98A00D106E83E28BB at FamilyPC>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=response
>
> Thanks for your thorough response Mark. We are actually in Nelson, BC and
> not on the coast. Nelson is not as humid or as wet as the coast but it's
> good to hear that about lime plaster as I think we may go that direction.
> Loving this list,
> Erica
>
> ----- Original Message -----
> From: "Mark BP / Low Energy Design Ltd" <mark at lowenergydesign.ca>
> To: "Erica Konrad" <strawbale at netidea.com>
> Cc: "SB REPP" <Strawbale at listserv.repp.org>; "SB Yahoos"
> <sb-r-us at yahoogroups.com>
> Sent: Tuesday, November 13, 2007 11:23 AM
> Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
>
>
>> Erica -
>>
>> If you're in one of the humid bits of BC, I would stongly advise not to
>> use stucco at all. I did a hygrothermal modelling exercise on this for
>> my
>> PhD a few years back, and found that for conditions in Cardiff (a bit
>> damper than the weather data I've seen for coastal BC, but not by much)
>> there is a real risk of bale moisture content reaching the sort of levels
>> that mould can grow at if the plaster is Portland cement based. There is
>> no such problem with clay or lime plaster.
>>
>> The reason for this is the low permeability to vapour flow of Portland
>> cement based plasters. Moisture that enters the wall can't get out
>> quickly enough. This is particularly a problem with the configuration
>> you
>> suggest - relatively easy for moisture to get in though high-permeability
>> clay plaster (in a heating climate the flow of moisture is from inside to
>> outside for the vast majority of the time), relatively difficult for it
>> to
>> get out again to the outside through the stucco.
>>
>> The results of my calculations were, of course, based on a whole series
>> of assumptions, as is any research in building physics. If you were to
>> keep your house at lower average humidity levels than I fed into the
>> model, you might be OK - but to do so involves greater energy consumption
>> (by maintaining higher temperatures throughout and/or increasing average
>> ventilation rates).
>>
>> Lime render, if applied correctly, is more than adequate for coping with
>> driving rain. The British Isles are littered with mediaeval castles that
>> used it (and it wasn't rain penetration that turned most of them into
>> ruins....) - in many cases you can see the continued success of
>> traditional plaster recipes not only against driving rain but also
>> against
>> salt spray. It has been used successfully for centuries on cob buildings
>> in the wet and windy west of England and in wet and windy Wales. So far
>> as I can see, the reason that so many Canadian sb builders use stucco has
>> nothing to do with superior performance and everything to do with
>> familiarity, availability, lack of skills & training (though it's
>> actually
>> not that difficult), etc. European sb builders are, on the whole, a lot
>> less inclined to use stucco.
>>
>> Your proposed course of action would work perfectly well here in SK. But
>> it's not a risk I would ever want to take in coastal BC.
>>
>> atb
>> Mark Bigland-Pritchard
>>
>>
>>
>> Erica Konrad wrote:
>>
>>>Dear all - I was wondering if there is any problem with plastering the
>>>interior of my strawbale home with earthen plaster and the exterior with
>>>stucco. We are in British Columbia in a pretty wet, wind exposed site and
>>>I would like to cover the exterior with stucco for this reason (won't be
>>>doing the stucco until the spring, but will work on the interior plaster
>>>(with heat) over the winter). Does is matter if both sides are different
>>>finishes in terms of moisture?
>>>Thanks in advance,
>>>Erica
>>>
>>>
>>>
>>>_______________________________________________
>>>Strawbale mailing list
>>>Strawbale at listserv.repp.org
>>>http://listserv.repp.org/mailman/listinfo/strawbale_listserv.repp.org
>>>
>>>
>>>
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 13 Nov 2007 22:43:24 -0600
> From: Mark BP / Low Energy Design Ltd <mark at lowenergydesign.ca>
> Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
> To: Erica Konrad <strawbale at netidea.com>
> Cc: SB Yahoos <sb-r-us at yahoogroups.com>, SB REPP
> <Strawbale at listserv.repp.org>
> Message-ID: <473A7CEC.20508 at lowenergydesign.ca>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> I haven't looked at the climate data for Nelson, but I understand you
> have quite damp winters (though not as damp as I was used to when I was
> in England). You would quite possibly be OK with stucco but personally
> I'd be cautious. And in any case lime plastering can be a lot of fun
> (if you have the time to do it...) If you need some help feel free to
> contact me - I don't consider myself an expert but the guy I learnt from
> in Devon, England definitely is. And I might be able to make it out to
> Nelson next year if, as I expect, I have other business in that general
> direction.
> Btw, could you let me know what you find out re local availability of
> lime. I've found 2 reliable outlets for type S lime in Saskatoon
> (having phoned every single building supply store), but no sources
> either of lime putty or of quicklime. I'd be interested to know if it's
> any easier in BC - especially as high-calcium limestone is quarried both
> in the Vancouver area and in parts of the Rockies.
> atb
> Mark
> Borden SK
>
>
> Erica Konrad wrote:
>
>>Thanks for your thorough response Mark. We are actually in Nelson, BC and
>>not on the coast. Nelson is not as humid or as wet as the coast but it's
>>good to hear that about lime plaster as I think we may go that direction.
>>Loving this list,
>>Erica
>>
>>----- Original Message -----
>>From: "Mark BP / Low Energy Design Ltd" <mark at lowenergydesign.ca>
>>To: "Erica Konrad" <strawbale at netidea.com>
>>Cc: "SB REPP" <Strawbale at listserv.repp.org>; "SB Yahoos"
>><sb-r-us at yahoogroups.com>
>>Sent: Tuesday, November 13, 2007 11:23 AM
>>Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
>>
>>
>>
>>
>>>Erica -
>>>
>>>If you're in one of the humid bits of BC, I would stongly advise not to
>>>use stucco at all. I did a hygrothermal modelling exercise on this for
>>>my
>>>PhD a few years back, and found that for conditions in Cardiff (a bit
>>>damper than the weather data I've seen for coastal BC, but not by much)
>>>there is a real risk of bale moisture content reaching the sort of levels
>>>that mould can grow at if the plaster is Portland cement based. There is
>>>no such problem with clay or lime plaster.
>>>
>>>The reason for this is the low permeability to vapour flow of Portland
>>>cement based plasters. Moisture that enters the wall can't get out
>>>quickly enough. This is particularly a problem with the configuration
>>>you
>>>suggest - relatively easy for moisture to get in though high-permeability
>>>clay plaster (in a heating climate the flow of moisture is from inside to
>>>outside for the vast majority of the time), relatively difficult for it
>>>to
>>>get out again to the outside through the stucco.
>>>
>>>The results of my calculations were, of course, based on a whole series
>>>of assumptions, as is any research in building physics. If you were to
>>>keep your house at lower average humidity levels than I fed into the
>>>model, you might be OK - but to do so involves greater energy consumption
>>>(by maintaining higher temperatures throughout and/or increasing average
>>>ventilation rates).
>>>
>>>Lime render, if applied correctly, is more than adequate for coping with
>>>driving rain. The British Isles are littered with mediaeval castles that
>>>used it (and it wasn't rain penetration that turned most of them into
>>>ruins....) - in many cases you can see the continued success of
>>>traditional plaster recipes not only against driving rain but also
>>>against
>>>salt spray. It has been used successfully for centuries on cob buildings
>>>in the wet and windy west of England and in wet and windy Wales. So far
>>>as I can see, the reason that so many Canadian sb builders use stucco has
>>>nothing to do with superior performance and everything to do with
>>>familiarity, availability, lack of skills & training (though it's
>>>actually
>>>not that difficult), etc. European sb builders are, on the whole, a lot
>>>less inclined to use stucco.
>>>
>>>Your proposed course of action would work perfectly well here in SK. But
>>>it's not a risk I would ever want to take in coastal BC.
>>>
>>>atb
>>>Mark Bigland-Pritchard
>>>
>>>
>>>
>>>Erica Konrad wrote:
>>>
>>>
>>>
>>>>Dear all - I was wondering if there is any problem with plastering the
>>>>interior of my strawbale home with earthen plaster and the exterior with
>>>>stucco. We are in British Columbia in a pretty wet, wind exposed site
>>>>and
>>>>I would like to cover the exterior with stucco for this reason (won't be
>>>>doing the stucco until the spring, but will work on the interior plaster
>>>>(with heat) over the winter). Does is matter if both sides are different
>>>>finishes in terms of moisture?
>>>>Thanks in advance,
>>>>Erica
>>>>
>>>>
>>>>
>>>>_______________________________________________
>>>>Strawbale mailing list
>>>>Strawbale at listserv.repp.org
>>>>http://listserv.repp.org/mailman/listinfo/strawbale_listserv.repp.org
>>>>
>>>>
>>>>
>>>>
>>>>
>>
>>
>>_______________________________________________
>>Strawbale mailing list
>>Strawbale at listserv.repp.org
>>http://listserv.repp.org/mailman/listinfo/strawbale_listserv.repp.org
>>
>>
>>
>>
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 14 Nov 2007 07:10:17 -0500
> From: Speireag Alden <speireag at gmail.com>
> Subject: Re: [Strawbale] Frost Heave (was re: Too Late to Plaster?)
> To: STRAWBALE at LISTSERV.REPP.ORG
> Message-ID: <p06230903c360943daf1f@[192.168.2.2]>
> Content-Type: text/plain; charset="iso-8859-1" ; format="flowed"
>
> Sgr?obh Robert Tom:
>
>>In order for frost heave to occur, two conditions must be present:
>>(i) moisture in the substrate
>
> nb: and since some moisture is always present, in order to heave
> it has to be enough moisture that when it expands on freezing, it
> over-fills any available voids.
>
>>Third, unlike rigid masonry or monlithic concrete structures, RTFs are
>>"flexible" and able to withstand lateral expansion stresses that would be
>>imparted to the material in the trench from adjacent soil that may be
>>subject to frost expansion.
>
> This is the part I've always been skeptical of. I've no doubt
> that an RTF will move about a tiny bit, but I've always suspected
> that it's not enough to make any difference in practice. I have
> read, though not from primary sources, that Frank Lloyd Wright, who
> used rubble trench foundations, tried to use them without driving
> them all the way to frost depth, relying on this movement to prevent
> heave damage, and got heave damage anyway.
>
>>So if one has to heat a building with an RTF in order to prevent frost
>>heave, then the RTF was designed/built improperly.
>
> I agree.
>
> In addition, any house necessarily raises the frost line around
> it, even if there's no intentional heat input.
>
> So, unless you leave the windows and doors open all winter, the
> house acts to retard frost penetration into the ground under and
> around the house. There is still some small amount of solar gain,
> and once the temperature of the house gets below the heat of the
> ground under it, the house itself acts as an insulation buffer for
> the ground it sits on.
>
> In my area, during a cold winter, frost can penetrate down as far
> as seven feet under plowed roads, but the frost line for building
> purposes is five feet.
>
> -Speireag.
>
> --
> A wise man will make haste to forgive, because he knows the true
> value of time, and will not suffer it to pass away in unnecessary
> pain.
> --Samuel Johnson, lexicographer (1709-1784)
>
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 14 Nov 2007 07:35:00 -0500
> From: Speireag Alden <speireag at gmail.com>
> Subject: Re: [Strawbale] stucco outside, earthen plaster inside?
> To: STRAWBALE at LISTSERV.REPP.ORG
> Message-ID: <p06230909c3609b90667d@[192.168.2.2]>
> Content-Type: text/plain; charset="iso-8859-1" ; format="flowed"
>
> Sgr?obh Mark BP / Low Energy Design Ltd:
>
>>And in any case lime plastering can be a lot of fun
>>(if you have the time to do it...)
>
> Second that. For me, plastering is meditative. I like doing it,
> so the fact that I'm *still* doing it on my own house doesn't bother
> me.
>
> Also, lime seems to hold up to what little driving rain we get
> around here, which isn't much. No sign of wear yet.
>
> -Speireag.
>
> --
> A wise man will make haste to forgive, because he knows the true
> value of time, and will not suffer it to pass away in unnecessary
> pain.
> --Samuel Johnson, lexicographer (1709-1784)
>
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 14 Nov 2007 11:21:21 EST
> From: Raftercat5 at aol.com
> Subject: Re: [Strawbale] ahh, finally have slab done
> To: strawbale at listserv.repp.org
> Message-ID: <d1e.117f6f49.346c7a81 at aol.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Just an update on our bldg progress on our post & beam SB house here in
> Cheraw, SC. Our PEX tubing has been placed and secured, and we had our
> slab
> poured 8 days ago. Just took off the plastic today, and now we're
> starting to
> put down the 4x4"s around the perimeter and anchoring them down with
> bolts
> embedded in the concrete. It's a good day...mid-70's and sunny.
> - Kathy
>
>
>
> ************************************** See what's new at
> http://www.aol.com
>
> ------------------------------
>
> _______________________________________________
> Strawbale mailing list
> Strawbale at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/strawbale_listserv.repp.org
>
> End of Strawbale Digest, Vol 17, Issue 6
> ****************************************
>
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