1. It is important to note that the minimisation of water loss using the system depends entirely on the correct laying procedures being followed.

2. It is recommended that all bitumen impregnated abe.^® ecofelt dams should have a perimeter fence to prevent the access of hoofed animals.

Frequent traffic by hoofed animals could lead to mechanical damage and seepage occurring. If the dam is required for livestock drinking water, it would be preferable to transfer the water to concrete troughs.

Construction 

The SABS Code of Practice forflexible Membranes (No. 10.25 1976) gives useful hints in the construction of earth dam and installation of membranes.

4. Depth 

Specifying Authorities recommend a maximum dam height of approximately 5 meters as a rule of thumb.

5. Water Table 

It is important that the dam be located/constructed above the existing ground water table. Perched water tables are easily formed and the resulting drawdown effect can have a negative influence on membrane joints. Thus the installation of a toe drain would be recommended for each application.

3. Vegetation 

All vegetation should be removed before construction of the dam. The decomposition of vegetation once the dam is in place will lead to the formation of gas under the membrane.

4. Embankments 

Maximum slopes of embankments should not exceed 1 : 2.5. This will allow easy preparation of the slopes for the membrane system.

5. Preparation of Floor 

Optimum compaction should be imparted to the floor and embankments of the dam. Generally a smooth surface needs to be attained.

6. Dam Inlet and Spillways 

Care should be taken to ensure protection of inlets and spillways of dams. Water flow at these points can cause scour and erosion.

7. Toe Drainage 

Due to the rapid drawdown effect, which can easily occur with fluctuating dam levels it is important that a sub-surface toe drain be constructed, to ensure that positive water pressure behind the joints of the lining is controlled.

8. Perimeter Anchor Trenches 

It is imperative that anchor trenches are constructed around the perimeter to ensure that no slippage of the lining occurs down the side-slopes. During flood conditions this anchor trench will assist in the prevention of damage caused to the liner by overtopping. (See sketch for details).

Compacted Soil or Sand Dams 

“super laykold Dam Lining System”, this application consists of a special rubberised bitumen emulsion used together with ecofelt non-woven needle punched polypropylene continuous filament membrane.

1. Do a final inspection of the treated compacted soil surface. Large protrusions such as rocks and sticks should already have been removed. Water pressure can cause damage to the lining when stretched over these protrusions.
2. Place one end of the a.b.e. ecofelt roll in the anchor trench furry side down, backfill with excavated material and compact well:
   • Unroll the ecofelt down the embankment at right angles to the trench and onto the dam floor for a few meters. This operation should continue slightly ahead of the super laykold Dam Lining rubberised bitumen application.
   • Overlaps – (150 – 300mm)

Both end and side flaps should be treated as follows: 

• Apply a liberal coat of 1.0 – 1.5 liter/m² onto the unrolled ecofelt at a width of 150 – 300mm.
• Immediately unroll the adjoining roll onto the coated overlap and ensure good contact by brooming the surface.
• Lay the ecofelt in manageable areas with overlaps completed, before commencing with the first saturation coat.

Dilute super laykold Dam Lining 1:1 with water in a suitable container.

Using soft brooms impregnate the ecofelt by dipping and brooming the emulsion into the membrane.

• Ensure application at approximately 2.5 to 3.0 liters/m² for the ecofelt.
• Allow to dry for 4 – 5 hours (depending on prevailing weather conditions)

Note: never attempt to shortcut the application by pouring the super laykold Dam Lining directly onto the ecofelt and then trying to spread the material. 

3. Apply two seal coats of undiluted super laykold Dam Lining at right angles to each other using broom as before allowing 3-4 hours between coats at approximately 1 liters/m² per coat.

This may be achieved by applying a known volume of undiluted material to a pre-measured area i.e. 10 liters should cover 10m².

4. All exposed super laykold surfaces, once they are dry, should be protected from U.V. breakdown by over-coating these surfaces with silvakote following a curing period of 2 days.

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.^® endeavours to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.^® has no direct or continuous control over where and how abe products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.^® products, whether or not in accordance with any advice, specification, recommendation, or information given by the company.

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements. a.b.e.^® has a wealth of technical and practical experience built up over years in the company’s pursuit of excellence in building and construction technology.