Sunday, October 02, 2016

Mastic Waterstops

Most commercially available mastic waterstops are sold in rolls or strips. The profile is usually a small rectangle or trapezoidal shape, with 3/4” x 1” being somewhat of a standard. These strips are adhered to existing concrete using an adhesive or primer, or alternately concrete nails at 12” on-center spacing. This adhesion is important, as only three sides of the waterstop will then be exposed to fresh concrete. If the waterstop is displaced during the concrete pour it can easily lose most if not all of its effectiveness. Also, like their similar hydrophilic cousin, mastic waterstops are designed for non-moving construction joints only. No expansion, isolation, or contraction joints.
Unlike hydrophilic waterstops, mastic waterstops are simply a strip of tacky, rubbery compound (usually based on bitumen and butyl rubber) that is designed to “stick” to a primed surface of a cured concrete cold joint on one side, and have fresh concrete cast against the remaining three sides, with the heat from the hydrating concrete causing the product to become even tackier, and therefore sealing the joint by acting as an internal, adhered sealant.

Obviously, this waterstop function is very limited as the only barrier to migrating fluids is the adhesion to the concrete and compression of the mastic waterstop product within the joint. For this reason, mastic waterstops tend to be more effective in construction situations where large concrete loads are applied on top of the waterstop such as wall on footing or burial vault lid, and far less effective when installed in vertical applications such as a wall joint.

Mastic waterstops are the lowest performing of any commercially available waterstop and are price accordingly, being the lowest cost waterstop as well. Because of the low cost and ease of installation, mastic waterstops are the favored products of commercial constructors and home builders.

Excerpt From: David Poole. “The Little Book of Waterstop.” Waterstop King, 2013. iBooks.

Saturday, September 24, 2016

Wednesday, January 27, 2016

Three New Waterstop Profiles for Environmental Engineered Concrete Structures

Earth Shield Waterstop is proud to announce three new waterstop profiles designed especially for environmental engineered concrete structures, such as waste and water treatment plants. All three profiles are ⅜" thick and have many interlocking ribs to grab into freshly poured concrete. Highlights of the new profiles include:
  • NSF 61 Certified for drinking water
  • Chemical resistant TPV polymer construction
  • Ozone resistant to 500 PPHM
  • UV resistant
  • Heat weldable thermoplastic
The new profiles can be downloaded in our CAD Library located here.


Wednesday, July 30, 2014

JP336L Retrofit Waterstop System — Installed in Concrete Joint Designs Where Space is Limited

Earth Shield JP336L Retrofit System — JP336L is designed primarily for non-moving construction joints, although it can handle limited joint movement due to the mechanical properties of the parent material. A primary advantage of JP336L is that the fastening leg on the waterstop can be field-trimmed to 1-1/2” — the size of the stainless steel batten bar. Therefore, JP336L takes up very little room within a joint making it perfect for retrofitting thin slabs or containment curbs.

JP336L Retrofit Waterstop
One (1) 10 lft length of “L” Shaped TPV Waterstop
One (1) 10 lft length of 3/16” x 1-1/2” Stainless Steel Batten Bar
Twenty (20) Stainless Steel Anchor Bolts (size: 2-1/4” x ¼”)

Friday, June 13, 2014

Saturday, April 19, 2014

Labyrinth Waterstop

Labyrinth waterstops are double-headed nailed to the formwork; therefore, obviating the need to split the formwork to accommodate one half of the waterstop. Because of their keyway-like shape and multitudinous miniature ribs they do an adequate albeit not stellar job of preventing the passage of water through non-moving construction joints.

Because of their non-symmetrical geometry they are very limited in regards to changes of directions.