FORMING REQUIREMENTS
Sika® Hydrotite® CJ profiles are installed after the form is stripped from the first pour and before the second concrete pour is made. Therefore, splitting of the form is not required. Sika® Hydrotite® can be installed to the plain surface of concrete or in a formed keyway. Due to the hydrophilic nature, installation of the profile should be timed as close as possible to the second placement of concrete. This will reduce the chance for premature expansion of Sika® Hydrotite® due to rainwater or ground water exposure. When extended periods are expected between pours along a common joint line, install Sika® Hydrotite® to a point slightly beyond the end of the first expected pour. Protect exposed length of Sika® Hydrotite® from moisture. In the event the exposed Sika® Hydrotite® exhibits expansion before the next placement of concrete, remove swelled material before splicing to a new length of Sika® Hydrotite®. Follow splicing instructions listed below.
SPLICING
Sika® Hydrotite® CJ profiles are designed with a cellular cross section. The cellular cross section allows the profile to compress slightly when concrete is placed and rebound as the concrete shrinks during cure. The cellular cross section also acts to control the expansive force placed on the surrounding concrete.
Straight lengths of CJ profiles should be cut square with a sharp knife or good pair of shears. Place several drops of a cyanoacrylate adhesive (i.e. Super Glue) on the cut ends of Sika® Hydrotite® and immediately join the ends together. Hold in position for approximately 30-45 seconds to allow the adhesive to set. Proper alignment and bonding of the cut ends will prevent water entering the cells of the profile. Future hydration of the waterstop will further seal the bond area.
Flat 90° corners should be spliced by miter cutting the two ends at 45° and proceeding in a manner similar to the above. When space permits, CJ-0725-3K and CJ-1020-2K can be bent to an inside radius of approximately 2 inches, eliminating a spliced joint. Flat “T’s” and “X’s” should be made by butt splicing the legs with the use of cyanoacrylate adhesive. Vertical 90° corners, vertical “T’s” and vertical “X’s” should be butted and bonded with the cyanoacrylate adhesive. All splices can be further enhanced by placing a bead of LEAKMASTER® LV-Z at the splice.
BONDING TO CONCRETE
Remove all dust, oil, laitance, etc., from concrete surface prior to adhering Sika® Hydrotite®. Depending on concrete surface conditions, one of several adhesives can be used.
Normal forming practice leaves a sufficiently smooth surface for direct bonding to the concrete by one of several methods. Sika® Hydrotite® CJ-1020-2K-ADH and CJ-0725-3K-ADH are profiles available with a “peel-and-stick” adhesive backing for fast and easy installation. Simply remove the release paper and press the profile firmly against the concrete in the desired location. Other Sika® Hydrotite® profiles can alternatively be secured with Sika® Hydrotite® Adhesive. The adhesive should be applied to both the profile and the concrete surface and allowed to dry to a tacky condition. Once this condition is met, place the profile into position. These methods work well when concrete surfaces are smooth and dry.
Concrete surfaces left rough due to jackhammering, extensive weathering, etc., should be brought to a smooth level condition. LEAKMASTER® LV-Z, a single component swellable sealant, can be used for this purpose when the concrete surface is dry. Apply a sufficient bead of LEAKMASTER® LV-Z to the rough concrete to ensure that a smooth level surface will result. Sika® Hydrotite® should be placed in position within 4 hours of application of LEAKMASTER® LV-Z. Concrete nails may be used on vertical or overhead surfaces to hold the profile in position while the LEAKMASTER® LV-Z cures.
A 2-part epoxy may also be used to level rough surfaces. Sika® Greenstreak® Epoxy 7300 can be used on rough, wet concrete surfaces to bond Sika® Hydrotite® profiles into position. Sika® Hydrotite® should be applied to the bed of epoxy prior to final cure, approximately 30 minutes. Again, concrete nails may be used on vertical or overhead applications while the epoxy cures.
