| Author |
Message |
Tom Gilmore, AIA, CCS, CCCA, LEED AP
Senior Member
Username: tgilmore
Post Number: 33
Registered: 04-2007
| | Posted on Thursday, May 31, 2012 - 01:21 pm: |    |
Do any of you have language you have used to require pre-filling a structural swimming pool box (above occupied spaces) to prestress the concrete and promote latent cracks prior to application of hot rubberized waterproofing (Am Hydro 6125/Henry 790-11)? Both my reps recommend this, but don't have examples. |
Gerard Sanchis
Senior Member
Username: gerard_sanchis
Post Number: 74
Registered: 10-2009
| | Posted on Thursday, May 31, 2012 - 02:11 pm: | |
Tom,
Two observations. The first is that asphalt – the main component of hot rubberized WP - is somewhat water soluble. If pool water gets to the waterproofing, thru cracks, it’ll form an oily film on the surface of the water. We had this happen to us in a reflecting pool for a large headquarter building in Burbank.
The second is directly related to the issue of pre-loading the pool. Assuming cracks develop during the pre-loading, we can assume that the hot rubberized WP which is self-healing will fill those cracks. When the pool is emptied for maintenance in the future and the cracks close will the WP ooze out of those cracks? We have a few examples of similar conditions in paving on WP in the L.A, area.
You may want to tell us a little more about the assembly. |
Dave Metzger
Senior Member
Username: davemetzger
Post Number: 429
Registered: 07-2001
| | Posted on Thursday, May 31, 2012 - 02:22 pm: | |
Tom:
Following is the wording we used for this condition, for a project that has now been completed.
Pre-Loading of Swimming Pool:
1. Prior to application of waterproofing, plug drains and fill swimming pool to full depth with water.
2. Maintain water level for 48 hours, then drain water.
3. The purpose of pre-loading is to allow concrete to crack under load of water prior to applying waterproofing, so that (after draining water, allowing concrete to dry, and testing for moisture as specified above), cracks can be treated as specified below as part of waterproofing application. |
Tom Gilmore, AIA, CCS, CCCA, LEED AP
Senior Member
Username: tgilmore
Post Number: 34
Registered: 04-2007
| | Posted on Thursday, May 31, 2012 - 02:33 pm: | |
Thanks. I'm forwarding your comments to my Am Hydro rep. |
Tom Gilmore, AIA, CCS, CCCA, LEED AP
Senior Member
Username: tgilmore
Post Number: 35
Registered: 04-2007
| | Posted on Thursday, May 31, 2012 - 03:04 pm: | |
Thanks. I'm forwarding your comments to my Am Hydro rep. |
Dave Metzger
Senior Member
Username: davemetzger
Post Number: 430
Registered: 07-2001
| | Posted on Thursday, May 31, 2012 - 03:11 pm: | |
Tom, the wording I sent was based on input from the Henry rep (and maybe Hydrotech also, it was written 4 years ago), so I really don't remember. |
Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1490
Registered: 07-2002
| | Posted on Thursday, May 31, 2012 - 03:17 pm: | |
An Architect friend of mine works for a company (Water Technology, Inc) that designs swimming pools (think Olympics, not residential). Here's his response:
For elevated pools located above occupied/ finished spaces WTI recommends secondary containment, typically this is a membrane application with the pool vessel built inside. The membrane can be EPDM or similar. To waterproof the concrete we utilize a Xypex material.
Matt is frequently somewhere else in the country (or world) working on a design or an install; WTI has done a lot of pools - successfully! Hope this information from someone I consider an expert helps. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 479
Registered: 10-2007
| | Posted on Thursday, May 31, 2012 - 05:09 pm: | |
Am not quite sure that the proposal to pre-load the pool is voodo science but I definately prefer the approach presented by Lynn.
Propose installing something between the pool concrete and the outer membrane to allow any water to leak out. Install enough reinforcement in the pool concrete to keep the cracks small and use Xypex in the concrete as an admixture. |
Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1491
Registered: 07-2002
| | Posted on Thursday, May 31, 2012 - 05:33 pm: | |
And the SE might want to investigate fiber reinforcement along with a low-shrinkage mix (less cement). |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 258
Registered: 12-2006
| | Posted on Thursday, May 31, 2012 - 06:59 pm: | |
Agreed about the sandwich slab. Remember to always include a drain where you have a membrane. I'd go with the hot-rubber. You'll only have one chance to get this one right. As a sandwich, the asphaltic product never gets near the pool water.
Admixture in the concrete is good too whether Xypex, Vandex, Aquafin, Vexconn etc.
Find a good coating for the concrete surface, preferably something that feels good to bare feet.
Good luck! |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 1268
Registered: 07-2002
| | Posted on Friday, June 01, 2012 - 01:47 pm: | |
I agree with Ken and Lynn --I want a waterproof assembly and then the pool is added. Most of the above-grade pools I've done have been the steel type, not a concrete "bowl" for the water. I typically use hot rubber for the construction around the pool (including the pool deck) and then the steel ones usually have tile installed over them on all the surfaces, so you can't tell they aren't a concrete pool I think the steel pool decision is both cost and weight related. (although it seems to me that the weight of the actual pool is probably the least important weight in this whole thing.)
I've done plenty of concrete pools/fountains/ponds - but they have always been on grade. |
Ellis C. Whitby, PE, CSI, AIA, LEED® AP
Senior Member
Username: ecwhitby
Post Number: 155
Registered: 03-2003
| | Posted on Friday, June 01, 2012 - 04:12 pm: | |
The concept of a second layer of protection below is excellent as far as it goes. There is another issue to consider:
Is the pool lighted? I had a project where the pool leaked into the building below because the conduit was left open while “flood testing”: no light fixture installed, no gasket/seal installed. Duct tape was used. Joy ensued as you can well imagine.
I also recommend the addition of water sensors in any conduit and spaces below the pool: if you get a leak early notification (at the drip stage) is better than a flood. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 259
Registered: 12-2006
| | Posted on Monday, June 04, 2012 - 01:14 pm: | |
Ellis, great point.
Back in the 80's we resorted to a glass pipe with a sign saying something along the lines of "Notify Facility Manager immediately if you see water flowing through this pipe." The pipe was in a back-of-house area with fairly high traffic. Thankfully there are better options but that seemed to comply with the KISS concept. |
4specs.com Home Page