[Strawbale] Bottom of wall detailing

[Rene Dalmeijer]

Jeff, Nick and others,

The weep screed is a nice product ( I would like to have it here in the 
Netherlands) but I think not the right thing to apply for external 
plaster on SB walls. It is absolutely essential that there is a tight 
bond between the plaster (whatever type) to the bottom of the wall. I 
have the very strong impression that a weep screed will interfere with 
this bond. The intention of the detail in Bruce's book is  that the 
plaster can rest on something firm to support the plaster. As detailed 
in earlier mails in this thread The plaster due to its higher modulus 
of elasticity carries the load. If the plaster is unable to do so due 
to not being properly supported this is the first location where the 
plaster can de-laminate from the strawbale wall. Inducing the primary 
failure mechanism for a plastered SB wall. Because the plaster is not 
supported by the straw it can now crack much more easily.

A weep screed used for its intended purpose for plasters on a wood 
frame backboard is an excellent product. Here the plaster is not 
carrying a load. Lifting the plaster away form the wood structure in a 
location where it is prone to de-lamination creating a capillary where 
water can creep potentially harming the substructure is a very good 
idea. Ending plaster in a a wel detailed manner is always good 
practice.

Rene
On Mar 29, 2007, at 19:00, strawbale-request at listserv.repp.org wrote:

> Message: 1
> Date: Wed, 28 Mar 2007 17:46:50 -0700
> From: Jeff Ruppert <jeff at odiseanet.com>
> Subject: Re: [Strawbale] Bottom of wall detailing
>

> Nick,
>
> Sorry for not including this also.
>
> http://www.nilesbldg.com/weepscreed.html
>
> If you want to be closer in compliance with codes, read everything with
> caution!  This type of research will only enlighten you, even if it 
> does
> not apply to your project.