Basement Tanking & Waterproofing Slurries
Basement tanking Porto hillside homes need differs from flat-site UK basements: negative-side pressure from Douro valley water tables plus historic barrel-vault cellars means a single coat of paint fails within one wet season.
What is included
- Hydrostatic pressure assessment
- Substrate preparation — raking out failed bitumen or cement
- Cementitious slurry (2–3 coats) or membrane specification
- Cavity drain membrane where continuous positive-side access exists
- Sump and pump sizing for habitable conversions
- Post-application flood test where structure allows
Why this matters for your property
A failed tanked wine cellar converted to a bedroom creates mold liability under Portuguese rental law — and €8,000–€15,000 retrofit costs.
Local expertise across Porto metro
Ramalde and Campanhã slope properties frequently have semi-buried kitchen extensions; we tank from the interior when external excavation is impossible on shared lanes.
FAQ
DPC blocks rising damp in walls; tanking resists lateral water pressure on below-ground structures. Many Porto cellars need both.
Typically 2–3 mm per coat, two coats minimum, bonded while the first is still green. Total system thickness stays under 6 mm.
Yes, after removing loose material and treating active leaks with plugging mortar. Vaulted ceilings need flexible detail at the springing points.
No. If meter readings show moisture climbing above 1 m on ground-floor walls, add DPC injection — tanking alone will not fix it.