This was a two-part job for the same school in Kota Damansara – a roof-level box gutter running along a metal roof, and a ground-level drainage channel between two blocks. Different heights, different exposure, same underlying problem: the existing waterproofing on both had reached the end of its service life and needed to be stripped back and redone before the next wet season found the gaps.

 The Problem: Two Failure Points, Two Different Conditions  

The ground-level channel was the more visibly urgent of the two – the old coating had cracked and flaked away in large sheets, exposing bare concrete underneath across most of the channel floor. Coating that’s failed this badly doesn’t just leak, it stops protecting the concrete itself, so the longer it’s left, the more the substrate underneath is exposed to standing water.

Up on the roof, the box gutter running alongside the metal roof sheeting was showing its age differently – old patching and general wear at the gutter’s low points, the kind of thing that doesn’t fail dramatically in one go but slowly stops doing its job during heavy rain.

 The Work: Strip, Prep, Recoat  

Both areas got the same basic treatment, adjusted for access. On the ground channel, the failed coating was cleared back to sound concrete before a fresh waterproof coating system went down – there’s no point coating over material that’s already lifting, since the new layer will just fail at the same weak points. Up on the roof, the team worked the box gutter section by section, rolling on the waterproofing coating by hand once the surface was prepped, working carefully around the roof’s fall lines so water still drains the way it’s supposed to once the coating cures.

 The Result  

Both the ground channel and the roof gutter came away with a uniform, fully bonded waterproof coating – no exposed concrete, no old patchwork left showing through. It’s not glamorous work, but box gutters and drainage channels are exactly where small failures turn into much bigger repair bills if they’re left running for another season or two.

 Why Vseal Engineering  

Gutters and drainage channels rarely get attention until they’re actively leaking, but they’re one of the easiest things to inspect and recoat before that happens. If your building has a box gutter, ground channel, or roof waterproofing that hasn’t been looked at in a few years, it’s worth a site visit before the next storm finds the weak point for you.

Call us at 011-5691 9902 or see our starting rates for common waterproofing work.