Waterproofing in Selangor

A common trap is a 'free survey' that always diagnoses rising damp and sells a chemical damp-proof course, when the real cause is condensation, a leaking gutter or bridged damp course. Get an independent, qualified diagnosis before paying for injected chemicals.

Damp proofing resists moisture and rising damp (like a damp-proof course in a wall); waterproofing resists liquid water under pressure, as in a basement below the water table. Below-ground and wet-area work needs true waterproofing, not just a damp treatment.

It depends on the method and area. Internal sealants and damp-proofing for a small area are the cheapest option; cavity-drain membranes and tanking cost more; a full basement or below-ground waterproofing system is the most expensive, running into five figures. The cause of the water dictates the right system.

Small sealant jobs on a minor damp patch are DIY-able, but below-ground waterproofing against groundwater pressure is specialist work — get it wrong and you trap water or flood the space. Full basement systems should be designed and installed by a qualified specialist.

Yes — reputable structural waterproofing comes with an insurance-backed guarantee so the cover survives if the contractor ceases trading. Ask whether the guarantee is company-backed or independently insured, because a company-only warranty is worth little if they close.

A properly installed cavity-drain or tanking system can last decades, and quality membranes carry long guarantees. Cheap surface coatings applied over an unaddressed water problem fail fast. Longevity depends on correct diagnosis and installation far more than the product.

A small sealant or bathroom job typically runs RM1,200-RM6,500, membrane systems RM6,000-RM28,000, and full structural waterproofing RM20,000-RM90,000.