High Quality Drainage Membrane
High quality drainage membranes are essential for protecting basement walls and foundations from ground pressure. They also prevent water from entering the waterproofing system.
These dimpled sheets are typically placed against the wall with the drainage layer facing soil. This ensures that the drain can function without any obstructions or blockages.
HYDRODUCT(r) 660
The HYDRODUCT(r) 660 is a prefabricated, dual-sided drainage composite, consisting of a dimpled polystyrene drainage core with non-woven filter fabric on one side and a polymer film on the other. It is a geotextile-based system designed to maintain permeability and protect the drainage composite from job site damage prior to and during the installation of the overburden. It is available to complement GCP’s PROCOR(r) fluid applied waterproofing membranes and BITUTHENE(r) bituminous waterproofing membranes.
It is recommended that a backfill be placed over the waterproofing membrane as soon as possible and be compacted. For areas that cannot be backfilled immediately, a termination bar is recom- mended across the top termination of the waterproofing membrane.
Where exposed membranes have lost adhesion, or where laps have not been sealed, all areas should be High quality drainage membrane clean, dry and covered with fresh Preprufe Tape, rolled firmly with the tinted release liner removed. Then, a hot air gun may be used to activate the adhesive with caution so as not to damage the membrane and firmly roll laps to achieve continuity.
Protecting the waterproofing membrane is important to prevent damage from other trades, construction mate- rials and backfill. A Preinstallation Conference should be held ap- propriate to the scheduled commencement of the waterproofing work to con- vince all parties involved in and around the waterproofing system that there is a need to take care not to damage or disturb the membrane during construction activities.
TERRAM Drainage Geocomposites
When two or more types of geosynthetic materials are bonded together to form an impervious barrier that performs a different function than they would individually, it is called a geocomposite. Examples of this include drainage geocomposites (with a high-density polyethylene net drainage core) and reinforcement geocomposites (bitumen and geotextile in a sheet).
Drainage geocomposites feature a nonwoven geotextile filter/separator or a geomembrane, bonded to a perforated HDPE pipe that forms the drainage core. These geocomposites are used as an alternative to traditional stone drains in applications such as highway edgedrains and under-drains. These drainage geocomposites can be tested in the laboratory using EN ISO 12958 or ASTM D4716 to determine transmissivity, which is the flow rate of water through the geocomposite.
The permeability of a geocomposite is determined by measuring the amount of water that flows through it in a specified time, at a specified pressure and at a given hydraulic gradient. The result is expressed in liters per second per meter width, or l/m*s.
A drainage geocomposite is often preferred to a traditional stone drain, especially for use in the backfilled side of retaining walls and bridge abutments. It is also used to intercept water in capillary zones where frost heave or salt migration may occur. These geocomposites have factory-assured properties and are easy to install. They can be installed with minimal impact to traffic, reducing installation time and minimizing road closures.
DELTA(r)-MS
DELTA(r)-MS is a clear cavity drain membrane used for waterproofing walls, floors and vaulted ceilings above or below ground in new construction and existing buildings with a contaminated or damp background. It is also suitable as a water control & drained management system for protection of sub-ground structures against adverse effects caused by ground water ingress.
Its air-gap technology, with over 8,900 dimples/m2, gives it superior drainage capacity that exceeds DIN 4095 (drainage rate of 0.6 l/sqm). This helps to keep basements permanently dry and protected against moisture intrusions. It is free from recycled materials and passes extensive external tests for long-term durability, resulting in a sustainable dampproofing solution that’s gentle on the environment and your budget.
DELTA(r)-MS is designed to be installed with Delta FAST-ners and nails, which significantly speeds up installation. It is a highly durable membrane with good chemical and environmental stress crack resistance (ESCR). It is easy to clean and is non-toxic and non-hazardous to handle.
Underseal(r) Blindside(tm) Membrane
For buildings that require a below-grade waterproofing membrane, but cannot wait until the concrete wall has been poured, blindside waterproofing is the solution. For these types of HDPE Dimple Geomembrane projects, a drainage and waterproofing membrane is sprayed directly onto the retaining wall before the concrete is poured. The resulting membrane, which withstands a significant amount of groundwater (estimated at 750,000 gallons per day), directs the water away from the building.
A number of manufacturers make products for this application. One popular product is Voltex, a bentonite sheet membrane from Cetco. Another option is the spray-on waterproofing system from Epro Waterproofing Services called EcoLine, which can be applied to a dimpled drainage sheet or a polyethylene liner.
In contrast, the 73-mil Underseal membrane from Polyguard is installed over a dimpled drainage mat and a nonwoven geotextile. It forms a strong mechanical and adhesive bond with the concrete when poured, preventing water migration and vapor adsorption. It also provides a barrier against toxic contaminants, such as methane and radon gas, that can leak through concrete cracks.
A final option is to use a liquid waterproofing, such as BEM or HYDRALASTIC 836 from W. R. Meadows, over a prefabricated drainboard or a layer of fine crushed beds/pea gravel. The liquid is then sprayed to a uniform thickness, and allowed to cure, as shown in this video. If a penetration or protrusion is encountered, a detailing fabric is applied to the membrane and a coat of BEM, HYDRALASTIC 836, or MEL-ROL LIQUID MEMBRANE (two-component) is then applied over the fabric.
