Saturday, October 10, 2026

—  Waterproofing

Waterproofing that starts with a diagnosis, not a guess.

From roofs and basements to tanks and wet areas, we trace water to its source before recommending a system — so the fix addresses the actual problem, not just where it happens to show.

9Waterproofing systems on offer
5-stageSurvey-to-handover process
Nairobi+On request across the region

—  Why waterproofing fails

Most repeat leaks come from the wrong fix, not a bad product.

Water rarely shows up where it enters. A stain on a ceiling can trace back to a roof penetration, a cracked parapet, or a failed joint metres away — and a coating applied to the visible symptom will fail again within a season.

We start every job with a proper site survey: tracing the path of water through the structure, checking substrate condition, and identifying every contributing factor before recommending a system.

—  Signs you need waterproofing

If any of this looks familiar, it's worth a site visit.

Damp patches or discolouration

Brownish staining on walls or ceilings, especially after rain.

Musty smell indoors

A persistent damp odour in basements, stores or lower floors.

Peeling paint or bubbling plaster

Finishes lifting away from the wall as moisture pushes through.

Visible mould or mildew

Dark spotting on walls, ceilings, grout lines or window reveals.

Pooling water on roofs or balconies

Water that doesn’t drain within a few hours of rain stopping.

Cracks in walls or foundations

Especially cracks that widen, or appear after heavy rain.

White mineral deposits (efflorescence)

A chalky residue on concrete or block walls.

Rising damp at wall bases

Discolouration or crumbling plaster near the floor line.

—  Our waterproofing services

Coverage for every part of the building envelope.

Roof waterproofing

Flat, pitched and podium roofs — membrane systems built for standing water and UV exposure.

Basement & foundation

Below-grade tanking and drainage to keep water out where hydrostatic pressure is highest.

Bathrooms & wet areas

Full membrane tanking under tile in showers, bathrooms, kitchens and laundries.

Water tanks

Internal and external tank waterproofing for potable and non-potable storage.

Swimming pools

Waterproofing for new pool shells and remedial work on leaking existing pools.

Balconies & terraces

Trafficable membrane systems that handle movement, drainage falls and finishes.

Crack injection & repair

Resin and cementitious injection for active leaks through cracks and joints.

Damp-proofing & rising damp

Chemical and physical damp-proof courses for walls affected by rising damp.

Gutters & drainage

Surface water management so roofs and podiums shed water instead of holding it.

—  Systems & materials

Matched to substrate, exposure and expected service life.

Bituminous membranes

Torch-applied and self-adhesive sheet membranes for roofs and large horizontal areas.

Liquid-applied membranes

Seamless, flexible coatings for complex details, upstands and penetrations.

Crystalline waterproofing

Penetrating systems for concrete tanks, basements and below-grade structures.

Resin & crack injection

Targeted repair for active leaks through cracks and construction joints.

Cementitious coatings

Rigid and flexible coatings for wet areas, tanks and internal wall treatment.

EPDM & sheet systems

Durable single-ply membranes for roofs with long-term UV exposure.

Damp-proof courses

Chemical injection and physical DPC systems for rising damp control.

Sealants & joint systems

Movement joint and sealant systems for balconies, terraces and facades.

—  Our waterproofing process

Five stages, each one written down.

01 — Site survey

Moisture mapping and visual inspection to trace water to its actual source.

02 — Diagnosis

We identify the cause and select a system matched to substrate and exposure.

03 — Written quote

Materials, labour, timeline and any prep work, laid out before anything starts.

04 — Application

Substrate preparation, primer, membrane or coating applied to spec.

05 — Inspection & handover

Flood or ponding test where applicable, plus care notes for the finished area.

—  Why choose Greysand for waterproofing

Built around getting it right the first time.

Waterproofing that fails is expensive twice over — once to apply, once to remove and redo.

Root-cause diagnosis

We trace the water path before quoting, not after the first attempt fails.

Manufacturer-approved systems

Products applied per manufacturer specification, not shortcuts on the mix.

Warranted workmanship

We stand behind the application, with support if something needs attention.

Post-application testing

Flood tests and inspections before we call a job finished.

—  Recent waterproofing work

Proof it holds up on site.

Bituminous membrane

Enkang Apartment

Kilimani, Nairobi

Dual-film bituminous membranes across residential blocks and common areas.

Crystalline + injection

Kenzi Residences / Cove

Nairobi

Crystalline waterproofing, resin injection and wet-area membranes.

Shaft waterproofing

Losai

Ngara, Nairobi

Specialised shaft waterproofing across service, ventilation and lift shafts.

—  Questions

Waterproofing, answered.

Damp-proofing manages moisture movement through a material. Waterproofing stops liquid water from penetrating a structure entirely. Which one you need depends on the diagnosis.
Most quality membrane systems are rated for 10–15+ years when correctly applied and maintained, though exposure, foot traffic and drainage design all affect real-world lifespan.
Sometimes — surface-applied systems can work over sound existing tile in specific cases. If the leak is beneath the tile, full re-tanking is usually needed. We’ll confirm after the survey.
Yes — workmanship is warranted, and materials carry their manufacturer warranty where applicable, confirmed in writing with your quote.
Most commonly: incorrect system for the exposure, poor substrate preparation, skipped primer coats, or treating the symptom rather than the source.
Some systems need a dry substrate and dry weather window to cure properly. We’ll advise on timing, and can prioritise urgent active leaks with interim measures.
Active leaks are usually addressed first with injection or targeted sealing, before a full membrane or coating system is applied around it.
Neither is universally better — crystalline suits concrete structures like tanks and basements, while membranes suit large horizontal areas like roofs and balconies.

Start with a waterproofing site survey.

Tell us what’s happening and where — we’ll assess the source and follow up with a written scope.