VAPOR BARRIERS - USE IN CONSTRUCTION WORK

Vapor barriers are not suitable for waterproofing applications. As their name implies, they prevent transmission of water vapor through a substrate in contact with the soil. Typically used at slabs-on-grade conditions, they also are used in limited vertical applications.

Vapor barriers are sometimes used in conjunction with other waterproofing systems, where select areas of the building envelope are not subject to actual water penetration.

Vapor barriers are discussed only to present their differences and unsuitability for envelope waterproofing.

As previously discussed, soils have characteristic capillary action that allows the upward movement or migration of water vapor through the soil. Beginning as water and saturating the soil immediately adjacent to the water source, the capillary action ends as water vapor in the upper capillary capability limits of the soil.

Vapor barriers prevent upward capillary migration of vapor through soils from penetrating pores of concrete slabs. Without such protection, delamination of flooring materials, damage to structural components, paint peeling, mildew formation, and increased humidity in finished areas will occur. Vapor barriers can also prevent infiltration by alkaline salts into the concrete slab and flooring finish.

Vapor barriers are produced in PVC, combinations of reinforced waterproof paper with a polyvinyl coating, or polyethylene sheets (commonly referred to as  visquene).

Polyethylene sheets are available in both clear and black colors in thicknesses ranging from 5 to 10 mil. PVC materials are available in thickness ranging from 10 to 60 mil.

Typical properties of vapor barriers are summarized in Table 2.9.

Vapor barriers are rolled or spread out over prepared and compacted soil, with joints lapped 6 in. Vapor barriers can be carried under, up, and over foundations to tie horizontal floor applications into vertical applications over walls. This is necessary to maintain the integrity of a building envelope.

Mastics are typically available from manufacturers for adhering materials to vertical substrates. In clay soil, where capillary action is excessive, laps should be sealed with a mastic for additional protection. Proper foundation drainage systems should be installed, as with all waterproofing systems.

Vapor barriers are installed directly over soil, which is not possible with most waterproofing systems. Protection layers or boards are not used to protect the barrier during reinforcement application or concrete placement.

CLAY SYSTEM APPLICATION - WATERPROOFING AND CONSTRUCTION

Natural clay waterproofing materials require the least preparatory work of all below-grade systems. Concrete substrates are not required to be cured except for rubberized asphalt combination systems. Concrete can be damp during installation, but not wet enough to begin clay hydration.

Large voids and honeycombs should be patched before application. Minor irregularities are sealed with clay gels. Most concrete curing agents are acceptable with clay systems.
Masonry surfaces should have joints stricken flush. Note the standard application detailsin Figs. 2.87, 2.88, and 2.89.

FIGURE 2.87 Clay system detail for foundation water-
proofing using mub slab.

FIGURE 2.88 Clay system detail for foundation water-
proofing without, with horizontal membrane applied directly
to grade.

FIGURE 2.89 Grade beam detailing for clay system.

Bentonite materials combined with butyl rubber require further preparation than other clay systems, including a dry surface, no oil or wax curing compounds, and no contaminants, fins, or other protrusions that will puncture materials.

The variety of bentonite systems available means that applications will vary considerably and have procedures similar to the waterproofing systems they resemble in packaging type (e.g., sheet goods). Bulk clay is applied like fluid membranes. Panels and sheetsas sheet-good systems, and butyl compound-polyethylene systems are applied virtuallyidentically to rubberized asphalt systems.

With bulk systems, proper material thickness application is critical as it is with fluid-applied systems. Bulk systems are sprayed or troweled, applied at 1–2 lb/ft^2of substrate.

Panel and mat systems are applied to vertical substrates by nailing. Horizontal applications require lapping only. These systems require material to be lapped 2 in on all sides.

Cants of bentonite material are installed at changes in plane, much the same way as cementitious or sheet-applied systems. Bentonite sheet materials are applied with seams shedding water by starting applications at low points.

Outside corners or turns receive an additional strip of material usually 1 ft wide for additional reinforcement (Fig. 2.90). Chalk lines should be used to keep vertical applications straight and to prevent fish mouthing of materials. All end laps, protrusions, and terminations should be sealed with the clay mastic, as shown in Figs. 2.91 and 2.92. Proper termination methods are shown in detail in Figs. 2.93 and 2.94.

FIGURE 2.90 Clay system applied to lagging detailing. Note reinforcement at corner.

FIGURE 2.91 Typical penetration detailing for clay system.

FIGURE 2.92 Pile cap detailing for clay system.

FIGURE 2.93 Termination detailing for clay system.

FIGURE 2.94 Termination detailing for clay system
using reglet.

CLAY SYSTEMS - WATERPROOFING AND CONSTRUCTION

Natural clay systems, commonly referred to as  bentonite, are composed primarily of montmorillonite clay. This natural material is used commercially in a wide range of products including toothpaste. Typically, bentonite waterproofing systems contain 85–90 percent of montmorillonite clay and a maximum of 15 percent natural sediments such as volcanic ash.

After being installed in a dry state, clay, when subjected to water, swells and becomes impervious to water. This natural swelling is caused by its molecular structural form of expansive sheets that can expand massively. The amount of swelling and the ability to resist water is directly dependent on grading and clay composition. Clay swells 10–15 percent of its dry volume under maximum wetting. Therefore, it is important to select a system high in montmorillonites and low in other natural sediments.

Bentonite clay is an excellent waterproofing material, but it must be hydrated properly for successful applications. Clay hydration must occur just after installation and backfilling, since the material must be fully hydrated and swelled to become watertight. This hydration and swelling must occur within a confined area after backfill for the waterproofing properties to be effective. Precaution must be taken to ensure the confined space is adequate for clay to swell. If insufficient, materials can raise floor slabs or cause concrete cracking due to the swelling action.


Clay systems have the major advantage of being installed in various stages during con- struction to facilitate the shortening of the overall building schedule or reducing any impact the waterproofing system installation might have. Clay systems can be installed before concrete placement by adhering the waterproofing product to the excavation lagging system as shown in Fig. 2.80, or against slurry walls or similar excavation and foundation support systems as detailed in Figs. 2.81 and 2.82.

FIGURE 2.80 Clay system applied directly to foundation lagging.

FIGURE 2.81 Clay system applied directly to shotconcrete foundation wall.

FIGURE 2.82 Application of clay panels directly to foundation sheet piling.

Clay systems can also be applied to the inside face of concrete formwork that is intended to be left in place due to site access constrictions; a similar installation photo- graph in shown in Fig. 2.83. These application methods permit the contractor to provide an effective waterproofing installation without having to delay the schedule awaiting the concrete placement and curing time necessary for other types of below-grade products.

FIGURE 2.83 Clay membrane applied to inside of concrete formwork.

 This also holds true for the typical waterproofing of elevator pits shown in Fig. 2.84.

Here the clay panels are laid directly on the compacted soils before concrete placement, without a working or mud slab required for the waterproofing installation. Again, this can save not only construction time but associated costs as well.

FIGURE 2.84 Typical clay system detailing for elevator pit with no mud slab required.

There is no concrete cure time necessary, and minimal substrate preparation is necessary. Of all waterproofing systems, these are the least toxic and harmful to the environment. Clay systems are self-healing, unless materials have worked away from a substrate. Installations are relatively simple, but clay is extremely sensitive to weather during installation. If rain occurs or groundwater levels rise and material is wetted before backfilling, hydration will occur prematurely and waterproofing capability will be lost, since hydration occurred in an unconfined space.

Immediate protection of applications is required, including uses of polyethylene covering to keep materials from water sources before backfill. If installed in below-grade conditions where constant wetting and drying occurs, clay will eventually deteriorate and lose its waterproofing capabilities. These systems should not be installed where free-flowing groundwater occurs, as clay will be washed away from the substrate.

Bentonite clays are not particularly resistant to chemicals present in groundwater such as brines, acids, or alkalines.

Bentonite material derivatives are now being added to other waterproofing systems such as thermoplastic sheets and rubberized asphalts. These systems were developed because bulk bentonite spray applications cause problems, including thickness control and substrate adhesion. Bentonite systems are currently available in the following forms:

● Bulk
● Fabricated paper panels
● Sheet goods
● Bentonite and rubber combination sheets
● Textile mats

Bulk bentonite
Bulk bentonite is supplied in bulk form and spray-applied with an integral adhesive to seal it to a substrate. Applications include direct installations to formwork or lagging before foundation completion in lieu of applications directly to substrates. Materials are applied at quantities of 1–2 lb/ft^2.

Bulk bentonite spray applications provide seamless installations. Controls must be pro- vided during application to check that sufficient material is being applied uniformly.

Materials should be protected by covering them with polyethylene after installation. Due to possibilities of insufficient thickness during application, manufacturers have developed several clay systems controlling thickness by factory manufacturing, including boards, sheets, and mat systems.

Panel systems
Bentonite clays are packaged in cardboard panels usually 4 ft^2, containing 1 lb/ft^2 of bentonite material. Panels are fastened to substrates by nails or adhesives. Upon backfilling, panels deteriorate by anaerobic action, allowing groundwater to cause clay swelling for water- proofing properties. On horizontal applications the panels are simply laid on the prepared substrates and lapped (Fig. 2.85).

FIGURE 2.85 Clay sheets installed under horizontal concrete slab; note the waterstop installed in the cold
joint.

These systems require time for degradation of cardboard panels before swelling and watertightness occurs. This can allow water to penetrate a structure before swelling occurs.

As such, manufacturers have developed systems with polyethylene or butyl backing to provide temporary waterproofing until hydration occurs.

Panel clay systems require the most extensive surface penetration of clay systems.
Honeycomb and voids should be filled with clay gels before panel application. Special prepackaged clay is provided for application to changes in plane, and gel material is used at protrusions for detailing.  Several grades of panels are available for specific project installation needs. These include special panels for brine groundwater conditions (Fig. 2.86), and reinforced panels for horizontal applications where steel reinforcement work is placed over panels.

FIGURE 2.86 Saltwater panel application.

Panels are lapped onto all sides of adjacent panels using premarked panels that show necessary laps.

Bentonite sheets
Bentonite sheet systems are manufactured by applying bentonite clay at 1 lb/ft^2 to a layer of chlorinated polyethylene. They are packaged in rolls 4 ft wide. The addition of poly-ethylene adds temporary waterproofing protection during clay hydration. This polyethylene also protects clay material from prematurely hydrating if rain occurs before backfilling and adds chemical-resistant properties to these systems.

Some manufacturers have developed sheet systems for use in above-grade split or sandwich slab construction. However, constant wetting and drying of this system can alter the clay’s natural properties, and waterproofing then depends entirely upon the polyethylene sheet.

Bentonite and rubber sheet membranes
Bentonite and rubber sheet membrane systems add clay to a layer of polyethylene, but also compound the bentonite in a butyl rubber com position. Materials are packaged in rolls 3 ft wide that are self-adhering using a release paper backing. They are similar to rubberized asphalt membranes in application and performance characteristics.

These combination sheet systems are used for horizontal applications, typically split- slab construction in parking or plaza deck construction. As with rubberized asphalt sys- tems, accessories must be used around protrusions, terminations, and changes in plane.

The polyethylene, butyl rubber, and bentonite each act in combination with the others, providing substantial waterproofing properties.

Unlike other clay systems, concrete substrates must be dry and cured before application.

Care must be taken in design and construction to allow for adequate space for clay swelling.

Bentonite mats
Bentonite mat systems apply clays at 1 lb/ft^2 to a textile fabric similar to a carpet backing.

This combination creates a carpet of bentonite material. The coarseness of the fabric allows immediate hydration of clay after backfilling, versus a delayed reaction with card-board panels.

The textile material is not self-adhering, and adhesives or nailing to vertical substrates is necessary. Protection with a polyethylene sheet after installation is used to prevent pre- mature hydration. This system is particularly effective in horizontal applications where the large rolls eliminate unnecessary seams. This lowers installation costs as well as prevents errors in seaming operations.

Properties of typical clay systems are summarized in Table 2.8.

HOT-APPLIED SHEET SYSTEMS - WATERPROOFING

Hot-applied systems are effectively below-grade roofing systems. They use either coal tar pitch or asphalts, with 30-lb roofing felts applied in three to five plies. Waterproofing technology has provided betterperformance materials and simpler applications, limiting ho systems usage to waterproofing applications.

Hot-applied sheet systems have installation and performance characteristics similar to those of roofing applications. These systems are brittle and maintain very poor elastic properties. Extensive equipment and labor costs offset inexpensive material costs. Below- grade areas must be accessible to equipment used for heating materials. If materials are carried over a distance, they begin to cool and cure, providing unacceptable installations.

Properties of typical hot-applied sheet systems are summarized in Table 2.7.

SHEET WATERPROOFING SYSTEM APPLICATION

Unlike liquid-applied systems, broom-finished concrete is not acceptable, as coarse finishes will puncture sheet membranes during application. Concrete must be smoothly finished with no voids, honeycombs, fins, or protrusions. Concrete curing compounds should not contain wax, oils, or pigments. Concrete surfaces must be dried sufficiently to pass a mat test before application.

Wood surfaces must be free of knotholes, gouges, and other irregularities. Butt joints in wood should be sealed with a 4-in-wide membrane detail strip, then installed. Masonry substrates should have all mortar joints struck flush. If masonry is rough, a large coat of cement and sand is required to smooth surfaces.

Metal penetrations should be cleaned, free of corrosion, and primed. Most systems require priming to improve adhesion effectiveness and prevent concrete dust from interfering with adhesion (Fig. 2.65).

FIGURE 2.65 Applying primer to concrete substrate in
preparation for sheet system.

All sheet materials should be applied so that seams shed water. This is accomplished by starting at low points and working upward toward higher elevations (Fig. 2.66). With adhesive systems, adhesives should not be allowed to dry before membrane application. Self-adhering systems are applied by removing a starter piece of release paper or polyethylene backing, adhering membrane to substrate (Fig. 2.67).

FIGURE 2.66 Application of sheet membrane.

FIGURE 2.67 Removing release paper backing from
self-adhering sheet membrane.

With all systems, chalk lines should be laid for seam alignment. Seam lap requirements vary from 2 to 4 in (Fig. 2.68). Misaligned strips should be removed and reapplied, with material cut and restarted if alignments are off after initial application. Attempts to correct alignment by pulling on the membrane to compensate may cause “fish mouths” or blisters.

FIGURE 2.68 Seam lap detailing for sheet membranes.

A typical sheet membrane application is shown in Fig. 2.69.

FIGURE 2.69 Typical sheet membrane application detailing.

At changes in plane or direction, manufacturers call for a seam sealant to be applied over seam end laps and membrane terminations (Fig. 2.70). Materials are back-rolled at all seams for additional bonding at laps (Fig. 2.71). Any patched areas in the membrane should be rolled to ensure adhesion.

FIGURE 2.70 Applying mastic termination detailing.

FIGURE 2.71 Back-rolling membrane at seams to
ensure bonding.

Each manufacturer has specific details for use at protrusions, joints, and change in plane (Fig. 2.72). Typically, one or two additional membrane layers are applied in these areas and sealed with seam sealant or adhesive (Fig. 2.73). Small detailing is sealed with liquid mem- branes that are compatible and adhere to the sheet material. Figure 2.74 details a typical col- umn foundation waterproofing application. Figure 2.75 shows the proper treatment of a control or expansion joint using sheet systems.

FIGURE 2.72 Transition detailing for sheet membranes.

FIGURE 2.73 Applying reinforcement strips at transition
details.

FIGURE 2.74 A column foundation waterproofing detail.

FIGURE 2.75 Expansion joint treatment using sheet system

Protection systems are installed over membranes before backfilling, placement of rein- forcing steel, and concrete placement. Hardboard, 1 8–1 4-in thick, made of asphalt-impregnated material is used for horizontal applications. Vertical surfaces use polystyrene board, 1 2-in thick, which is lightweight and applied with adhesives to keep it in place during back-fill. Sheet systems cannot be left exposed, and backfill should occur immediately after installation.


Protrusions through the membrane must be carefully detailed as shown in Fig. 2.76.

FIGURE 2.76 Protrusion detailing for sheet systems.

 Manufacturers require an additional layer of the sheet membrane around the penetration that is turned on or into the protrusion as appropriate. A bead of sealant or mastic is applied along the edges of the protrusion. For expansion joints in below-grade walls or floors, the installation should include appropriate waterstop and the required additional layers of membrane (Fig. 2.77). Sheet systems must be terminated appropriately as recommended by the manufacturer. Termination details prohibit water from infiltrating behind the sheet and into the structure. Termination bars are often used as shown in Fig. 2.78. Reglets can be used (Fig. 2.79); these also permit the termination of above-grade waterproofing in the same reglet that then becomes a transition detail.

FIGURE 2.77 Expansion joint treatment incorporating waterstop.

FIGURE 2.78 Termination of sheet membrane using termination bar.

FIGURE 2.79 Termination of sheet membrane using
reglet.

SHEET MEMBRANE WATERPROOFING SYSTEMS

Thermoplastics, vulcanized rubbers, and rubberized asphalts used in waterproofing applications are also used in single-ply roofing applications. Although all systems are similar as a generic grouping of waterproofing systems, consider their individual characteristics whenever you choose systems for particular installations.

Sheet membranes have thickness controlled by facto manufacturing. This ensures uniform application thickness throughout an installation. Sheet manufactured systems range in thickness from 20 to 120 mil. Roll goods of materials vary in width from 3 to 10 ft.

Larger widths are limited to horizontal applications, because they are too heavy and difficult to control for vertical applications.

Unlike liquid systems, sheet system installations involve multiple seams and laps and are not self-flashing at protrusions and changes in plane. This is also true for terminations or transitions into other members of the building envelope.

Applications below grade require protection board during backfill operations and concrete and steel placements. Fins and sharp protrusions in substrates should be removed before application, or they will puncture during installation. Materials used in vertical applications should not be left exposed for any length of time before backfilling.

Weathering will cause blistering and disbonding if backfill operations must begin immediately after membrane application.

Vertical single-ply applications are more difficult than fluid applications, due to the difficulty of handling and seaming materials. Seams are lapped and sealed for complete

waterproofing. In small, confined areas such as planter work, vertical installation and transitions to horizontal areas become difficult and extra care must be taken.

Thermoplastics
Thermoplastic sheet-good systems are available in three compositions: PVC, chlorinated polyurethane (CPE), and chlorosulfonated polyethylene (CSPE), which is referred to as hypalon. Materials are manufactured in rolls of varying widths, but difficulty with vertical applications makes smaller widths more manageable.

On horizontal applications, wider roll widths require fewer seams; therefore, it is advantageous to use the widest workable widths. All three systems adhere by solvent- based adhesives or heat welding at seams.

PVC membranes are available in thicknesses of 30–60 mil. CPE systems vary by as much as 20–120 mil, and hypalon materials (CSPE) are 30–35 mil. All derivatives have excellent hydrostatic and chemical resistance to below-grade application conditions. PVCmembranes are generically brittle materials requiring plasticizers for better elastomeric properties, but elongation of all systems is acceptable for below-grade conditions.

Vulcanized rubbers
Vulcanized rubbers are available in butyl, ethylene propylene diene monomer (EPDM), and neoprene rubber. These materials are vulcanized by the addition of sulfur and heat to achieve better elasticity and durability properties. Membrane thickness for all rubber systems ranges from 30–60 mil. These materials are nonbreathable, and will disbond or blister if negative vapor drive is present.

As with thermoplastic materials, vulcanized rubbers are available in rolls of varying widths. Seam sealing is by a solvent-based adhesive, as heat welding is not applicable. A separate adhesive application to vertical areas is necessary before applying membranes.

Vulcanized rubber systems incorporate loosely laid applications for horizontal installations.

Although other derivatives of these materials, such as visquene, are used beneath slabs as dampproofing membranes or vapor barriers, they are not effective if hydrostatic pressure exists. Material installations under slabs on grade, by loose laying over compacted fill and sealing joints with adhesive or heat welding, are useful in limited waterproofing applications.

This is a difficult installation procedure and usually not specified or recommended.

Loosely laid applications do, however, increase the elastomeric capability of the mem- brane, versus fully adhered systems that restrict membrane movement.

Rubberized asphalts
Rubberized asphalt sheet systems originally evolved for use in pipeline protection applications. Sheet goods of rubberized asphalt are available in self-adhering rolls with a  polyethylene film attached. Self-adhering membranes adhere to themselves, eliminating the need for a seam adhesive. Sheets are manufactured in varying widths of 3–4 ft and typically 50-ft lengths.

Also available are rubberized asphalt sheets reinforced with glass cloth weave that require compatible asphalt adhesives for adhering to a substrate. Rubber asphalt products require a protection layer, to prevent damage during backfill or concrete placement operations.

Self-adhering asphalt membranes include a polyethylene film that acts as an additional layer of protection against water infiltration and weathering. The self-adhering portion is protected with a release paper, which is removed to expose the adhesive for placement.

Being virtually self-contained, except for primers, this system is the simplest of all sheet materials to install. Figure 2.64 details a typical below-grade installation.

FIGURE 2.64 Below-grade sheet waterproofing system detailing.

Self-adhering membranes are supplied in 60-mil thick rolls, and accessories include compatible liquid membranes for detailing around protrusions or terminations. Rubberized asphalt systems have excellent elastomeric properties but are not used in above-grade exposed conditions. However, membrane use in sandwich or split-slab construction for above-grade installations is acceptable.

Glass cloth–reinforced rubber asphalt sheets, unlike self-adhering systems, require no concrete curing time. Separate adhesive and seam sealers are available. Glass cloth rubber sheets are typically 50 mil thick and require a protection layer for both vertical and horizontal applications. Typical properties of sheet materials are summarized in Table 2.6.

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.

FLUID-APPLIED SYSTEMS - WATERPROOFING

Fluid-applied waterproof materials are solvent-based mixtures containing a base of urethanes, rubbers, plastics, vinyls, polymeric asphalts, or combinations thereof. Fluid membranes are applied as a liquid and cure to form a seamless sheet. Since they are fluid applied, controlling thickness is critical during field application (see Fig. 2.47).

Therefore, field measurements must be made (wet or dry film) for millage control. The percentages of solids in uncured material vary. Those with 75 percent solids or less can shrink, causing splits, pinholes, or insufficient millage to waterproof adequately.

Fluid systems are positive waterproofing side applications and require a protection layer before backfilling. Fluid-applied systems are frequently used because of their ease of application, seamless curing, and adaptability to difficult detailing, such as penetrations and changes in plane. These systems allow both above- and below-grade applications, including planters and split-slab construction. Fluid systems are not resistant to ultraviolet weathering and cannot withstand foot traffic and, therefore, are not applied at exposed areas.

FIGURE 2.47 Spray application of fluid-applied membrane.

Several important installation procedures must be followed to ensure performance of these materials. These include proper concrete curing (minimum 7 days, 21–28 days preferred), dry and clean substrate, and proper millage. Should concrete substrates be wet, damp, or uncured, fluid membranes will not adhere and blisters will occur. Proper thickness and uniform application are important for a system to function as a waterproofing material.

Materials can be applied to both vertical and horizontal surfaces, but with horizontal applications, a subslab must be in place so that the membrane can be applied to it. A topping, including tile, concrete slabs, or other hard finishes, is then applied over the mem- brane. Fluid materials are applicable over concrete, masonry, metal, and wood substrates.

Note the application to below-grade concrete block wall in Fig. 2.48.
Fluid-applied systems have elastomeric properties with tested elongation over 500 percent, with recognized testing such as ASTM C-836. This enables fluid-applied systems to bridge substrate cracking up to  1 16-in wide.

FIGURE 2.48 Fluid-applied membrane application to below-grade block wall.

An advantage with fluid systems is their self-flashing installation capability. This application enables material to be applied seamless at substrate protrusions, changes in planes, and floor-wall junctions. Figure 2.49 details a typical below-grade application using fluid membranes. Fluid materials are self-flashing, with no other accessories required for transitions into other building envelope components. However, a uniform 50–60 mil is difficult to control in field applications, and presents a distinct disadvantage with fluid systems.

FIGURE 2.49 Typical below-grade application detailing for fluid-applied membranes.

These systems contain toxic and hazardous chemicals that require safety protection during installation and disposal of materials. Refer to Chap. 14 and the discussion on V.O.C. materials.

Fluid-applied systems are available in the following derivatives: urethane (single or two-component systems), rubber derivatives (butyl, neoprene, or hypalons), polymeric asphalt, coal tar, or asphalt modified urethane, PVC, and hot applied systems (asphalt).

Urethane
Urethane systems are available in one- or two-component materials. Black coloring is added only to make those people who believe waterproofing is still “black mastic” comfortable with the product. Urethanes are solvent-based, requiring substrates to be completely dry to avoid membrane blistering.

These systems have the highest elastomeric capabilities of fluid-applied membranes, averaging 500–750 percent by standardized testing. Urethanes have good resistance to all chemicals likely to be encountered in below-grade conditions, as well as resistance against alkaline conditions of masonry substrates.

Rubber derivatives
Rubber derivative systems are compounds of butyls, neoprenes, or hypalons in a solvent base. Solvents make these materials flammable and toxic. They have excellent elastomeric capability, but less than that of urethane membranes.

Rubber systems are resistant to environmental chemicals likely to be encountered below grade. As with most fluid membranes, toxicity requires safety training of mechanics in their use and disposal.

Polymeric asphalt
A chemical polymerization of asphalts improves the generic asphalt material qualities sufficiently to allow their use as a below-grade waterproofing material. Asphalt compounds do not require drying and curing of a masonry substrate, and some manufacturers allowinstallation of their asphalt membranes over uncured concrete.

However, asphalt materials are not resistant to chemical attack as are other fluid systems. These membranes have limited life-cycling and are used less frequently than other available systems.

Coal tar or asphalt-modified urethane
Coal tar and asphalt-modified urethane systems lessen the cost of the material while still performing effectively. Extenders of asphalt or coal tar limit the elastomeric capabilities and chemical resistance of these membranes.

Coal tar derivatives are especially toxic, and present difficulties in installing in confined spaces such as small planters. Coal tar can cause burns and irritations to exposed skin areas. Field mechanics should take necessary precautions to protect themselves from the material’s hazards.

Polyvinyl chloride
Solvent-based PVC or plastics are not extensively used in liquid-applied waterproofing applications. These derivatives are more often used as sheet membranes for roofing. Their elastomeric capabilities are less than other fluid systems and have higher material costs.
They do offer high resistance to chemical attack for below-grade applications.

Hot-applied fluid systems
Hot-applied systems are improvements over their predecessors of coal tar pitch and felt materials. These systems add rubber derivatives to an asphalt base for improved performance, including crack-bridging capabilities and chemical resistance.

Hot systems are heated to approximately 400°F in specialized equipment and applied in thickness up to 180 mil, versus urethane millage of 60 mil (see Fig. 2.50). Asphalt extenders keep costs competitive even at this higher millage. These materials have a considerably extended shelf life compared to solvent-based products, which lose their usefulness in 6 months to 1 year.

FIGURE 2.50 Application process for hot-applied membrane.

Since these materials are hot-applied, they can be applied in colder temperatures than solvent-based systems, which cannot be applied in weather under 40°F. Manufacturers often market their products as self-healing membranes, but in below-grade conditions this is a questionable characteristic. Properties of typical fluid-applied systems are summarized in Table 2.5.