[Cob] Lime Render - FAILURE

[Bill Wright]

Hi Michel,
I certainly don't claim to be a lime render expert, nor did my email, "blame" the NHL for this issue; at least not intentionally. It's NOT my intention to find someone or something to blame. I'm simply wanting to find the best solution possible moving forward given where I currently stand.

I am confused by your comment, "The little lime that you included in your plaster is barely enough to help stabilize the mortar but certainly not have reacting as a lime mortar." Is 3 Parts Sand to 1 Part Lime not common?

I think one draw back here it that I also don't know exactly what recipe is outlined by your other comment, "The protection from the elements is achieved by following the proportions and instructions which given by TransMineral". I haven't availed myself of that information, so I don't know what constitutes your ideal proportions/instructions.

Thanks for any solutions you might offer. Not the least of which might be to advise me regarding a clear coating you might recommend that I could coat over this existing exterior wall to make it water resistant. Any/all comments appreciated from your experience and perspective.

Many Thanks!
Bill

Bill Wright, L.Ac., DNBAO
Wright Acupuncture and Massage
251 Auburn Ravine Rd., Ste. #205
Auburn, CA 95603
530-886-8927
"There is no path to healing, healing is the path" 


> On Feb 17, 2017, at 1:17 PM, <transmin at sonic.net> <transmin at sonic.net> wrote:
> 
> Dear Mr. Wright,
>  
> I was surprised to received this email titled “Lime Render – FAILURE” as the render described in your email refers to some kind of earth plaster and NOT a lime render. The little lime that you included in your plaster is barely enough to help stabilize the mortar but certainly not have reacting as a lime mortar. The presence of clay in your mix does not allow for exposure to the elements and I am surprised that you had to wait one year to witness a failure. Secondly, the protection of this “brown coat” is totally inappropriate, not counting the inclusion of clay.
> To use clay of unknown qualities, even in smaller proportions, in an exterior application is looking for trouble at some point in time.
> The protection from the elements is achieved by following the proportions and instructions which given by TransMineral. This has not been the case here.
> Please, do not blame the NHL for this failure, but rather the “creativity” of whoever specified this kind of application.
>  
> Sincerely,
>  
>  
> Michel Couvreux
> TransMineral USA, Inc.
> 201 Purrington Rd - Mailing Address
> Petaluma, CA 94952
> 2105 S. McDowell Blvd, Suite D - Showroom
> Petaluma, CA 94954
> 707-769-0661
> 707-769-0352 Fax
> transmin at limes.us
> www.limes.us
>  
>  
> From: Bill Wright
> Sent: Friday, February 17, 2017 9:43 AM
> To: coblist at deatech.com
> Subject: Lime Render - FAILURE
>  
> Happy New Year of the Fire Rooster All!
>  
> I'm attaching photos here for you to view online (below my message ;^).
>  
> The images show the cracking of a lime render applied less than (1) year ago over an earthen brown coat. The Brown coat was 3 parts sand to 1 part - 90% indigenous site clay and 10% lime (NHL 3.5). The final lime render was 2.5 parts sand to 1 part - 90% lime (NHL 2.0) and 10% indigenous site clay. A pigment from Trans-Mineral USA was added for color to the recommended acceptable amounts according to the manufacturer of the pigment. (I think TM USA was the source, I know we got our lime from them - St. Austier NHL).
>  
> My Natural Home Builder and I believe that the greater than average rains in Northern CA this winter have saturated the lime render to the point of moisture moving thru the lime to the clay brown coat underneath; which is expected, and not usually a problem. . .  Not a problem UNLESS the clay expands and cracks the lime render above; which we believe is the mechanism of how the lime is cracking.
>  
> The real problem is two fold:
>  
> A. I'll bet my bottom dollar the County will not pass my building w/ cracks in the render - big ouch!
>  
> B. The process of water expanding the clay underneath is progressing to the point that the lime is delaminating and falling off in certain areas. While this is not really a huge structural issue, it's a bummer, and it's unsightly to say the least. Over time, it could start to wear down the cob/earthen layer beneath it, which will create more work to fix it.
>  
> So, my question is this. . . What would you do next to remedy this situation and create a functioning wall given my current situation?
>  
> PICTURES:
> 
> https://www.dropbox.com/s/ib58lvdq5crtly4/File%20Feb%2017%2C%207%2059%2025%20AM.jpeg?dl=0
>  
> https://www.dropbox.com/s/5y52e8x455ngiuv/File%20Feb%2017%2C%208%2000%2012%20AM.jpeg?dl=0
>  
> https://www.dropbox.com/s/uwfe9b638zsi1z4/File%20Feb%2017%2C%208%2000%2055%20AM.jpeg?dl=0
>  
> https://www.dropbox.com/s/ut8bxeksxbhb2y4/File%20Feb%2017%2C%208%2001%2023%20AM.jpeg?dl=0
>  
> Many Thanks!
> 
> Bill
> 
> Bill Wright, L.Ac., DNBAO
> Wright Acupuncture and Massage
> 251 Auburn Ravine Rd., Ste. #205
> Auburn, CA 95603
> 530-886-8927
> "There is no path to healing, healing is the path"
>