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?
A
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.
Are there concerns about compatibility with other materials (e.g., rebar, insulation, concrete additives)?
A
Generally, these membranes are compatible with concrete and rebar. However, designers should verify compatibility with any special admixtures or adjacent systems.
Common materials include HDPE, TPO, FPO and TPR. Each has different performance characteristics such as chemical resistance, flexibility, and water impermeability. However, the best is HDPE pre-applied membrane which is tested by time, especially for methane and radon resistance.
Will the membrane affect future maintenance or renovations?
A
Since the membrane is bonded to the concrete, it is well-protected and rarely requires maintenance. However, any major structural changes may require professional assessment.
Typically, these membranes are designed for a service life of 25–50 years, depending on the product and environmental conditions. For high quality product, such as PMH 3040/PLUS and PMH 3080/PLUS could last as long as the designed life of structure
Why should I choose a pre-applied membrane over traditional waterproofing systems?
A
Pre-applied membranes offer enhanced protection against water migration, improved durability, reduced risk of leaks due to their full adhesion to the structure and saved construction time, labor and expense.
What is a polymer pre-applied waterproofing membrane?
A
A polymer pre-applied waterproofing membrane is a waterproof sheet applied before the concrete pour. It bonds permanently to structural concrete, creating a secure barrier against water ingress.
