Damp course system

Jenny Dickens asks about an "Electro Osmotic Dampcourse System
[that] has been recommended to an architect colleague for use on an
historic building." (Cons DistList Inst. 15:11)

I recall a good discussion on this method in John and Nicola
Ashurst's Practical Building Conservation: English Heritage
Technical Handbook Volume 1: Stone Masonry or Volume 2: Brick,
Terracotta, and Earth (English Heritage 1988, Halsted Press). Those
volumes in my library have been loaned out, and I can't recall in
which one it was discussed (perhaps both).

I looked into this method briefly a few years ago for a dampproofing
project on a late 19th century brick church. Because of the lack of
data at that time, we could not be certain of the effectiveness of
the procedure so we opted for an injected chemical dampcourse
instead. It has been very effective for the past 7 or 8 years,
although I can't say what the lifespan of the intervention may be.
>From a conservation standpoint, the obvious advantage of the electro
osmotic system is that it is less intrusive and is more reversible
as compared to an injected dampcourse.

Another helpful publication may be Porous Building Materials by
Giorgio Torraca (1988 ICCROM). He discusses the electrical movement
of water within porous solids. This work would be good background
info to understand how the electro osmotic technique works.

John Horton, RA
Restoration Specialist
NC State Historic Preservation Office


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                  Conservation DistList Instance 15:12
                   Distributed: Friday, July 13, 2001
                       Message Id: cdl-15-12-005
                                  ***