[Cob] Another inquiry on sealants...

[Benjamin Brownell]

Thank you Henry, yes I am looking specifically for durable waterproofing treatments that will protect exposed cob/plaster surface, but not a standard walled building situation. Say for example, an earthen bench or sculpture in a park, without any roofing, in temperate climate (cool damp winters) for at least two years without any harm. If anyone feels like natural oil/wax are sufficient, please speak up. You mentioned driveway sealer, do you mean asphaltic coating? I haven't worked with that, and guess it significantly affects the nature of the finished surface, but curious what you have achieved. What other hardware-store (or special order) waterproofing would be suited, and have you used them?

--- On Wed, 11/3/10, Henry Raduazo <raduazo at cox.net> wrote:

From: Henry Raduazo <raduazo at cox.net>
Subject: Re: [Cob] Another inquiry on sealants.If you have a good roof over a cob structure there is no reason other than esthetic to do anything else to it. If you wall is going to set out in the rain you need to do something and nothing that I have found is perfect. You must also consider the environment that the cob is in. The worst situation is a warm heated house and a cold exterior exposed to water. Here the only thing that I know of is lime finish because it sheds water and permits evaporation of moisture from inside the wall.
    If both sides of the wall are equal temperature and the same humidity then you can coat the wall with almost any water proofing that you want.