Waterproof Blue Explained: A Liquid Replacement for Plastic DPMs and DPCs
If you've worked on a block-and-beam floor or a kicker block detail, you'll know the usual approach: loose-laid plastic DPM sheet, taped and dressed up the upstands, hoping every lap joint holds. Waterproof Blue does it differently: a roller-applied liquid membrane that cures into one seamless, jointless barrier.
What Waterproof Blue Actually Is?
Waterproof Blue is a polymer-modified, water-based liquid membrane, VOC-free, applied by roller or brush in two crosswise coats. Where a plastic DPM relies on overlaps and taped joints to stay watertight, Waterproof Blue has none; it's a single monolithic layer once cured, with nothing to lift, tear or puncture during follow-on trades.
It goes anywhere you'd traditionally specify a plastic damp proof membrane or damp proof course:
- Block-and-beam floors - rolled on before screed.
- Kicker block upstands - no taped corners required.
- Foundation walls, basement floors and slabs.
- Behind coping stones - stops water tracking into brickwork.
DPM or DPC - Does It Matter Which You Call It?
Not really in practice; the two terms describe the same job at different orientations (DPM for horizontal surfaces like floors, DPC for vertical ones like walls), and Waterproof Blue is suitable for both.
Added Radon Protection
Because it forms a continuous, unbroken membrane, Waterproof Blue also carries radon barrier certification - useful on sites in higher radon-risk areas, where the ground floor build-up needs to double as both a damp proof membrane and a gas barrier.
Working on a foundation, floor or basement detail? Contact us today.