| Author |
Message |
David G. Axt, CCS, CSI ,SCIP
Senior Member
Username: david_axt
Post Number: 1825
Registered: 03-2002
| | Posted on Monday, August 26, 2019 - 02:44 pm: |    |
My client told me that they have had problems with self-expanding waterstops causing cracking in the foundation walls. I have been specifying those products for years and have never heard of them causing that problems. Have you?
David G. Axt, CCS, CSI, SCIP
Specifications Consultant
Axt Consulting LLC |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 1232
Registered: 12-2006
| | Posted on Monday, August 26, 2019 - 03:57 pm: | |
Just the bentonite products. Apparently it can displace concrete, especially when placed too close to the edge.
I try to limit expanding waterstops to Chloroprene Rubber. There are several decent manufacturers. If they claim it costs too much, tell them to price PVC. |
Colin Gilboy
Senior Member
Username: colin
Post Number: 466
Registered: 09-2005
| | Posted on Monday, August 26, 2019 - 04:29 pm: | |
From a 4specs advertiser I asked to comment:
Unfortunately that is a real problem with self-expanding strip waterstops. If they are placed too close to the concrete edge, they can swell up and pop out of the concrete while it is still uncured and weak.
Usually a concrete clear cover of two to four inches* is adequate to ensure that this blowout doesn’t take place. This problem is especially pronounced when using waterstop products containing large amounts of sodium bentonite.
Modern chemically modified chloroprene rubber waterstops are far less prone to this problem then their sodium bentonite equals.
If blowout occurs in concrete from waterstop expansion, the fix is relatively simple with the application of hydraulic cement in the effected areas.
David R. Poole
JP Specialties
Colin Gilboy
Publisher, 4specs.com
702-505-9119 - Las Vegas
|
Ed Storer
Senior Member
Username: ed_storer
Post Number: 28
Registered: 05-2009
| | Posted on Wednesday, September 11, 2019 - 06:08 pm: | |
I get annoyed specifying waterstops, where the concrete is covered with legitimate waterproofing.
The envelope consultants I've dealt with seem to want them in every nook & cranny of the concrete.
I include their recommended products in the specifications because the envelope consultant is hired by the Owner. It's the Owner's money being spent needlessly. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 1236
Registered: 12-2006
| | Posted on Wednesday, September 11, 2019 - 08:12 pm: | |
I'm more upset that not enough Structural Engineers bother to understand concrete technologies and their effects on architectural features, including keeping water out of the building. Their focus is typically limited to building function related to structural related code issues.
Waterstops can provide real benefit, especially swellable and injectable types. Considering how questionable some waterproofing products are and how details don't always address real-life issues that are encountered, a belt-and-suspender approach may not be a bad idea. Unfortunately I don't personally know any Structural Engineers that know more about this than many experienced Specifiers do.
When it comes down to it, the best option is still the first rule of waterproofing; when the water's not there, it doesn't leak. |
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