Detergent in mortar/render - harmful or not?

[Tomfh]

I've heard everything from "It's fine" to "It will result in total structural failure".

Does anyone have any hard information on this matter?

 

[hokie66]

Tomfh,

My attitude to using dishwashing detergent as a plasticising admixture is "Why would you do it?" Proprietary admixtures are readily available for this purpose, and they are not expensive. I know bricklayers will sometimes use common kitchen detergent, but I don't think it is acceptable practice.

 

[concretemasonry]

Totally unfounded, uncontrolled and not acceptable. - If an engineer accepts it that is his problem.

I say this in spite of the long (centuries) history of mortar to be adaptable and accesptable for all uses.

Exactly what is the application? That may shed some light on the reason for the use. Surfactants/soaps have been used for years in concrete when they got promoted to being called "plasticizers".