Cement stucco – air + water control layer
user-7600779
| Posted in General Questions on
Hi everyone;
I was reading some document from BSC where it is suggested to apply an air and water control layer in the cement block walls. Between the blocks and the external insulation.
I was wondering, can mortar directly applied over the blocks acts as a water control layer? I know that this kind of render can act as an air control layer. How about water? (Even knowing the cement render can crack).
Thank you in advance.
ER
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
ER, while lime-based plaster is airtight, I'm not sure that a thin coat of cement-based parging would be considered airtight, especially since it will tend to crack at the CMU joints. High-strength concrete can be watertight but a thin layer of mortar will not stop water movement. It would be better to use an elastomeric coating or a membrane designed for that purpose.