FLUID SYSTEM APPLICATION - WATERPROOFING

Substrate preparation is critical for proper installation of fluid-applied systems. See Fig.2.51 for typical fluid system application detail. Horizontal concrete surfaces should have a light broom finish for proper bonding. Excessively smooth concrete requires acid etching or sandblasting to roughen the surface for adhesion.

Vertical concrete surfaces with plywood form finish are satisfactory, but honeycomb, tie holes, and voids must be patched, with fins and protrusions removed (Fig. 2.52).

Wood surfaces must be free of knotholes, or patched before fluid application. Butt joints in plywood decks should be sealed with a compatible sealant followed by a detail coat of membrane. On steel or metal surfaces, including plumbing penetrations metal mustbe cleaned and free of corrosion. PVC piping surfaces are roughened by sanding before membrane application.

FIGURE 2.51 Typical application detailing of below-grade fluid-applied membrane.

FIGURE 2.52 Preparation of block wall prior to membrane application.

Curing of concrete surfaces requires a minimum of 7 days, preferably 28 days. On subslabs, shorter cure times are acceptable if concrete passes a mat dryness test. Mat testing is accomplished by tapping visquene to a substrate area. If condensation occurs within 4 hours, concrete is not sufficiently cured or is too wet for applying material.

Blistering will occur if materials are applied to wet substrates, since they are non- breathable coatings. Water curing is the recommended method of curing, but some manu- facturers allow sodium silicate curing compounds. Most manufacturers do not require primers over concrete or masonry surfaces; however, metal substrates should be primed and concrete if required (Fig. 2.53).

FIGURE 2.53 Roller application of fluid-applied membrane.

All cold joints, cracks, and changes in plane should be sealed with sealant followed by a 50–60-mil membrane application, 4-in wide. Figure 2.54 details typical locations where additional layers of membrane application are required for reinforcement.

FIGURE 2.54 Reinforcement detail of membrane at changes-in-plane and areas of high stress. (Note
sealant cant added at floor-wall juncture, and membrane layers at changes-in-plane.)

Cracks over 1/ 16-in should be sawn out, sealed, then coated. Refer to Fig. 2.55 for typical detailing examples.

FIGURE 2.55 Substitute crack detailing and preparation for membrane appliation.

At wall-floor intersections, a sealant cant approximately 1 2–1 in high at 45° should be applied, followed with a 50-mil detail coat. All projections through a substrate should be similarly detailed. Refer again to Fig. 2.56 for typical installation detailing. At expansion joints and other high-movement details, a fiberglass mesh or sheet flashing is embedded in the coating material. This allows greater movement capability.

FIGURE 2.56 Transition detailing for membrane applications.

Figure 2.57 provides a perspective view of a typical below-grade fluid-applied membrane application using a sheet material to reinforce the horizontal-to-vertical transition.

FIGURE 2.57 Perspective detail emphasizing the reinforcing of the wall-to-floor transition.

The detail coat applied at this point provides additional protection at the same transition.
This detail emphasizes the 90%/1% principle, assuming that the weak point in this structure (wall to floor juncture) is a likely candidate for water infiltration. Recognizing this, the manufacturer has tried to idiot-proof the detail by adding several layers of protection, including the waterstop and drainage board that properly completes the waterproof installation.

The detailing provided in Fig. 2.58 shows a fluid membrane application that runs continuously on the horizontal surface, including beneath the wall structure. Many engineers will not permit such an application due to the membrane acting as a bond break between the wall and floor components that might present structural engineering problems.

FIGURE 2.58 Application detailing using drainage board in lieu of protection board for additional
waterproofing protection.

In Fig. 2.59, the manufacturer has detailed the use of a liquid membrane over foundation lagging using a fluid-applied membrane before the concrete is placed. In this detail, the membrane is applied to a sheet-good fabric that acts as the substrate. This is applied over a premanufactured drainage mat to facilitate water drainage and hydrostatic pressure.

FIGURE 2.59 Fluid-applied membrane detail for application directly to foundation lagging.

This would be a difficult application, and not as idiot-proof as using a clay system in a similar installation as outlined later in this chapter.

All penetrations occurring through a membrane application must be carefully detailed to prevent facilitating water infiltration at this “90%/1% principle” envelope area. Figure 2.60 shows a recommend installation at a pipe penetration. Note that the concrete has been notched to install sealant along the perimeter of the pipe. The waterproof membrane is then detail-coated around the pipe, followed by the regular application.

FIGURE 2.60 Penetration detailing for membrane waterproofing applications

Fluid-applied membrane applications all require that the termination of the membrane be carefully completed to prevent disbonding at the edge and resulting water infiltration. Figure 2.61 shows the membrane terminating with a sealant of manufacturer-supplied mastic. Figure 2.62 details the use of a reglet to terminate and seal the membrane, which could also simultaneously be used to terminate above-grade waterproofing.

FIGURE 2.61 Termination detailing for membrane waterproofing.

FIGURE 2.62 Reglet termination detailing for membrane waterproofing.

Control coating thickness by using notched squeegees or trowels. If spray equipment is used, take wet millage tests at regular intervals during installation. Application by roller is not recommended. Pinholes in materials occur if a substrate is excessively chalky or dusty, material cures too fast, or material shrinks owing to improper millage application.

Fluid membranes are supplied in 5- or 55-gal containers. Their toxicity requires proper disposal methods of containers after use. Since these materials rapidly cure when exposed to atmospheric conditions, unopened sealed containers are a necessity.

These materials are not designed for exposed finishes. They will not withstand traffic or ultraviolet weathering. Apply protection surfaces to both horizontal and vertical applications. On vertical surfaces, a
1 2-in polystyrene material or other lightweight protection system is used. For horizontal installations a
1 8-in, asphalt-impregnated board is necessary. On curved surfaces, such as tunnel work, 90-lb. roll roofing is usually acceptable protection. For better protection and detailing, use premanufactured drainage board in lieu of these protection systems (Fig. 2.63).

FIGURE 2.63 Application of premanufactured drainage board in lieu of protection board to protect mem-
brane.