Interior waterproof membrane

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Author Message John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 848 Registered: 03-2002 Posted on Friday, February 15, 2008 - 08:12 am:    My corporate client has a large data center with offices above (in new construction). They want to have a waterproof membrane on the slab above, underneath the carpet tile, in case of misc. mechanical or plumbing leaks. The initial concept is a resinous mechanical room membrane, but that seems more expensive than needed for this application. What have others done is similar situations? Ellis C. Whitby, AIA, PE, CSI, LEED® AP Senior Member Username: ecwhitby Post Number: 44 Registered: 03-2003 Posted on Friday, February 15, 2008 - 08:43 am:    While working for a pervious AE firm I was involved with similar situations for computer rooms and an archive. In those situations we installed metal pans under all the wet piping and equipment in the ceiling above the mechanical room. The pans had moisture sensors installed to provide warning. The wet piping was routed together wherever possible to minimize the extent of the pans. The pans were tied to drain lines outside of the extent of the “critical” area. Obviously we were more concerned about leaks from piping directly above the servers than we were about leaks on the floor above. If your client is still concerned about the floor above, why not use continuous sheet goods? No seams, no leaks. Sprinkler piping is always a problem since providing pans under their entire extent requires that virtually the entire ceiling area have pans except at the heads. Richard A. Rosen, CSI, CCS, AIA Senior Member Username: rarosen Post Number: 28 Registered: 08-2006 Posted on Friday, February 15, 2008 - 08:57 am:    If the structure above is a concrete slab look into a crystalline waterproofing. Crystalline WP is a blend of portland cement, specially treated sand, and active chemicals that, when mixed with water and applied, penetrates by capillary action into concrete or masonry and reacts chemically with free lime in the presence of water to develop crystalline growth within concrete or masonry capillaries to produce an impervious, dense, waterproof concrete. Check out Aquafin-1C, Vandex Super, or Xypex. Lynn Javoroski CSI CCS LEED™ AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 729 Registered: 07-2002 Posted on Friday, February 15, 2008 - 09:13 am:    We use a liquid waterproofing membrane or a CPE sheet under finish floor (usually tile) in toilet/shower rooms on elevated slabs where spaces below are occupied. I suppose it could be more extensively used...Laticrete 9235 is one liquid/membrane and Nobleseal TS is one sheet. Dave Metzger Senior Member Username: davemetzger Post Number: 253 Registered: 07-2001 Posted on Friday, February 15, 2008 - 09:28 am:    The advantage of crystalline W/P is that it is cementitious, and the adhesion of finish flooring adhesives should not be an issue. The membranes used under ceramic tiles are made to work with portland cement-based setting beds. Will carpet tile adhesives adhere to these membranes, or to urethane based membranes such as used for traffic-bearing waterproofing in mechanical rooms (eg Pedagard M by Neogard)? Mark Gilligan SE, CSI Senior Member Username: mark_gilligan Post Number: 33 Registered: 10-2007 Posted on Friday, February 15, 2008 - 10:33 am:    What is the floor structural system? I like crystaline WP but would want to verify it's apropriateness for use with concrete over metal deck construction. Reinforcement is typically light resulting in very noticable cracks. The cracks are typically hidden by floor covering and are not a concern structurally. How do you deal with drainage if the floor does not slope? John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 849 Registered: 03-2002 Posted on Friday, February 15, 2008 - 11:45 am:    Structure is steel with vented composite metal deck. Since there is no water under normal conditions, drainage is not considered. The expectation is that, in a leakage event, the water would flow to the edges of the membrane where it would probably leak into the floor below, but outside of the data center area. I had the concerns that Dave expressed about adhesion, too. I would expect carpet to stick just fine to cementitious waterproofing membranes manufactured by tile setting materials companies. I'm not so sure about adhesion to the resinous mechanical room membrane. I had not thought of the crystalline products--I'll check into that, though crack-bridging could be an issue. Any other ideas? Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 721 Registered: 07-2002 Posted on Friday, February 15, 2008 - 01:17 pm:    John- in a comparable condition for a mid-town Manhattan project, I used a urethane concrete (Ucrete) product under the finish flooring, after verifying compatibility. in our case, the office "kitchen" (coffee machine, refrigerator/icemaker) was above the computer facility and we allowed for the possibility of a bucket of water overturning on the floor and sitting there for a while. the resin or urethane floor is expensive, but it was a relatively small area, and the cost compared to failure was very small. its easy to visually inspect the product application and also to cove up at the base so that you do contain a spill. I have the same concerns about the crystalline products -- they should be added to the mix, so where do you make that break? and they won't work with cracks, either. Jo Drummond Senior Member Username: jo_drummond_fcsi Post Number: 13 Registered: 06-2007 Posted on Friday, February 15, 2008 - 02:59 pm:    The concrete over the metal deck may be lightweight structural concrete (100-110 pcf), that's what it would be in So. Cal. It is very susceptible to cracking, and it can have large cracks. I wonder if a shrinkage compensating admixture, such as Ipanex, could be added to the concrete, then use a crystalline waterproofing. Anonymous   Posted on Friday, February 15, 2008 - 01:27 pm:    John, You need an inexpensive, bullet proof membrane for this and I recommend that you look at Protecto Wrap's AFM. Typically used under tile, it is self adhering, butt jointed at the seems, with a fabric scrim facing to accept tile. I suspect that this will also accept adhesively installed carpet, most certainly stretched. Give them a call, they have many products and can offer/provide many solutions. Mark Gilligan SE, CSI Senior Member Username: mark_gilligan Post Number: 34 Registered: 10-2007 Posted on Saturday, February 16, 2008 - 11:55 am:    The cracks in the composit deck are not primarily due to concrete shrinkage. These slabs typically have minimal reinforcing steel and what there is tends to be at the top of the decking. Thus there is no reinforcing to resist the negative moments at the beams supporting the slab. Naturally it cracks. To make the cracks go away you would need to add considerable reinforcing in the slab. This would also reduce the size and spacing of shrinkage cracks. These cracks are not a safety problem..