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Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre

Post Number: 946
Registered: 07-2002


Posted on Tuesday, April 20, 2010 - 09:11 pm:   Edit PostDelete PostPrint Post

pardon me if this is an old topic covered somewhere else (I can't find it) but I need a terminology check. While I was working for big complicated firms on big complicated projects, there was nothing on the drawings or in the specs that might be thought of as "dampproofing" and I never used the term.
now that I'm working on smaller projects with smaller architects and contractors, this word is showing up on the drawings. I'm thinking that no such thing exists, but I would like a consensus of the practitioners out there before I send a note to the architect.
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman

Post Number: 852
Registered: 03-2003


Posted on Tuesday, April 20, 2010 - 09:17 pm:   Edit PostDelete PostPrint Post

Refer to ASTM D 1079 and NRCA Roofing and Waterproofing Manual. Both have nearly identical definitions.

Waterproofing - Treatment of a surface or structure to prevent the passage of water under hydrostatic pressure.

Dampproffing - Treatment of a surface or structure to resist the passage of water in the absence of hydrostatic pressure.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com
Mark Gilligan SE, CSI
Senior Member
Username: mark_gilligan

Post Number: 271
Registered: 10-2007
Posted on Tuesday, April 20, 2010 - 09:22 pm:   Edit PostDelete PostPrint Post

2009 IBC Section 1805 requires damproofing in some situations.
Ron Beard CCS
Senior Member
Username: rm_beard_ccs

Post Number: 350
Registered: 10-2002


Posted on Wednesday, April 21, 2010 - 01:07 am:   Edit PostDelete PostPrint Post

The term dampproofing was pretty common even on large projects in the 1950's and 1960's and earlier. It was traditionally an unmodified bitumen bi-product left over from the road construction industry. It was often used on either the inside or the outside of masonry walls and, as Ron has indicated, in moisture retarding related applications in the absence of hydrostatic pressure. Waterproofing applications back then generally were bituminous-felt systems similar to built-up roof systems. With the exception of cement parging and bentonite, I can't recall any non-bituminous waterproofing products being available.

Back in the mid-1960's, I watched a +/- 10-story solid masonry office building being torn down to make room for the new Washington Post building in Washington, DC. The top floor was a solid 8" thick solid brick wall with each lower floor of an additional 4" wythe of brick. The walls were about 7' thick at the foundation level. Dampproofing was usually placed on the inside face of the walls.

The phenomenon known as rising damp was a well known characteristic of solid masonry structures. Tar and other bituminous layers were often applied horizontally [full thickness of the wall] high in the foundation walls but below the first floor line to imped the upward rise of water/moisture. The upper scale structures used a piece of slate for the same reason since it is imperious to water.

I don't know as a fact, but I am assuming, that the two applications, both impeding moisture, were applied interchangably. Most specifiers today have a basic understanding of the moisture drive through a building but, unfortunately, a surprising number of architects don't. In fact, some don't even have a clue; so misuse of the terms dampproofing and waterproofing is not uncommon.
"Fast is good, but accurate is better."
.............Wyatt Earp
Mark Gilligan SE, CSI
Senior Member
Username: mark_gilligan

Post Number: 272
Registered: 10-2007
Posted on Wednesday, April 21, 2010 - 01:36 am:   Edit PostDelete PostPrint Post

The horizontal membrane through the wall still shows up in some more modern concrete and masonry details. When this happens be prepared for poor performance in an earthquake
(Unregistered Guest)
Unregistered guest
Posted on Wednesday, April 21, 2010 - 08:32 am:   Edit PostDelete PostPrint Post

MasterSpec's discussion for 071113 can answer a lot of these questions.

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