What are the advantages of EVA membranes over other materials like HDPE or PVC?
A
EVA membranes offer a good balance of elasticity, durability, and low-temperature flexibility. Compared to HDPE, they are easier to weld and more flexible. Compared to PVC, they are generally more chemically resistant and environmentally stable.
EVA (Ethylene-Vinyl Acetate) waterproofing membranes are flexible, thermoplastic sheets commonly used for waterproofing applications in tunnels, subways, basements, and water reservoirs. They are known for their flexibility, chemical resistance, and ease of welding.
What happens if the membrane is damaged during rebar work or pouring?
A
Minor damages can usually be repaired using manufacturer-approved patches. It’s essential to inspect and fix damages before pouring concrete. You can use cover tape for small area and cut a bigger piece of membrane, place on top of damage, sealed by cover tape for large area.
Seams are usually overlapped and sealed using heat welding, cover tapes or double-sided tape depending on the system. Pipe penetrations and corners require sealant, compatible coating as accessories or detailing work.
How is the membrane fixed in place before pouring concrete?
A
The membrane is typically loosely laid on the compacted soil or lean/blinding concrete and secured with dual self-adhesive laps, adhesive strips, or weldable edge. End laps and corner joints require proper sealing using specified methods depending on which product.
What surface preparation is needed before installation?
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The substrate (typically blinding concrete or compacted soil) must be smooth, clean, and free of sharp protrusions. Some products can tolerate damp surfaces, but standing water should be removed.
Can it be integrated with post-applied systems or other waterproofing methods?
A
Yes, the PMH pre-applied system can be seamlessly transitioned to post-applied membranes or used in combination with liquid waterproofing at terminations or penetrations.
