Waterproofing · Colombo
C&S Projects is a waterproofing supplier in Colombo for all four system families - cementitious, liquid-applied, polyurea and sheet membrane. We supply to your contractor, or supply and install through our own teams. If you are still choosing a system, our waterproofing systems guide compares them for Sri Lankan conditions.
Supply only
Materials, data sheets and consumption rates for your applicator.
Stock
All four system families are supplied and, where required, installed. Every line comes with the technical data sheet and the consumption rate per square metre, so whoever applies it can hit the specified waterproofing build-up.
In store now are Mapelastic Smart, a flexible two-component cementitious system for wet areas, and Planiseal 288 for structures under pressure. Browse all Waterproofing products.
How we work
Materials can be supplied on their own to a contractor with the relevant experience. Data sheets, method statements and consumption rates come with the order, so the application is correct.
For most clients we recommend supply-and-apply, for one specific reason. It removes the gap between the material warranty and the installation warranty. When a supplier sells and a separate contractor installs, a debonded membrane becomes an argument between two parties.
| What you get | Supply only | Supply and apply |
|---|---|---|
| Materials, data sheets and consumption rates | ||
| Method statement for your applicator | ||
| Substrate survey before quotation | On request | |
| Preparation, detailing and application |
Local exposure
Colombo combines monsoon load, sustained humidity, UV on exposed slabs and - near the coast - salt exposure. Therefore the exposure condition should drive system selection, rather than the price per square metre. The Department of Meteorology seasonal outlook is a sensible input when programming the work.
On exposed flat roofs, the usual failure point is not the open slab. It is the detailing at outlets, upstands and pipe penetrations. As a result, seamless liquid systems are often the safer choice on Colombo's irregular roof geometry.
Below grade, the constraint is different. A high water table in parts of the city puts real hydrostatic pressure on basements, so drainage design matters as much as the tanking. For roof work specifically, see Roof waterproofing in Colombo.
Before a price
We survey before we quote wherever the site allows. A waterproofing quotation issued without seeing the substrate is a guess. The survey is also where the honest cost conversation happens.
Preparation and repair are the line items most often left out of a cheap quotation, and they are not optional. For how those lines affect the total, read Waterproofing cost in Sri Lanka.
The survey establishes
Logistics
Waterproofing materials are supplied on a schedule against the site programme. Most systems have a defined pot life once opened, and Colombo sites rarely have storage. Ex-stock lines move quickly; specialist and imported systems are flagged as indent at quotation.
Programme note
Schedule waterproofing ahead of the monsoon, not during it. Most liquid systems need a defined substrate moisture content and a rain-free curing window. A membrane forced between showers is a membrane that will debond.
The unglamorous lines
The membrane gets the attention, but the supporting products decide whether it holds. They are also the lines most often dropped from a quotation to make the rate look competitive. We quote them separately so you can see they are there.
Bond the membrane to the substrate. The wrong primer, or none, is the fastest route to a debonded system.
Restore honeycombing and open cracks before coating, so the membrane is not asked to bridge what it cannot.
Round the sharp wall-to-slab junction, where a membrane would otherwise be stretched thin and split.
Embedded at outlets, corners and penetrations, where movement and water concentrate on every roof.
Close movement and construction joints that a continuous membrane should never be expected to span alone.
Topcoats or wearing layers that keep UV and foot traffic off the membrane on exposed and trafficked areas.
Accurate quotes
A few details up front turn a rough estimate into an itemised quotation. Photos help more than people expect - especially of outlets, upstands and any existing damp patches on the ceiling below.
In store now
Live from the catalogue, with real photos and current prices.
Quick answers
On supply-only orders, we issue the method statement and consumption rates. If your applicator has questions about primers, coats or detailing, our technical team will answer them before work starts, not after a failure.
Usually a cementitious system with potable-water approval where the tank holds drinking water. The substrate and any existing coating decide the exact product, so we confirm it against the tank's condition first.
Because the product is rarely what fails. Preparation, film thickness and detailing decide the outcome. A cheap membrane applied well can outlast a premium one applied badly, but neither survives missing preparation.
Product to surface
Buying the right material starts with naming the surface honestly. This is how the surfaces we are asked about most map to system families - the starting point for a conversation, not a substitute for a survey.
A flexible two-component cementitious system, applied before tiling, with extra reinforcement at floor drains, corners and the shower tray junction.
A cementitious system, with potable-water approval where the tank holds drinking water. Existing coatings are checked for compatibility first.
Cementitious tanking, designed alongside drainage - in high water table areas the drainage matters as much as the membrane itself.
A liquid-applied membrane in a UV-stable grade, or with a reflective topcoat to keep the slab cooler and reduce daily movement.
A sheet membrane can be efficient here, with laps and terminations detailed carefully because they are its controlled risk.
In short
Assurance
ISO 9001:2015Quality Management System · Certified
CCI Sri LankaChamber of Construction Industry · MemberGood to know
Supply only or supplied and installed - quoted by system, with lead times stated.
Supply and apply
Survey, preparation and installation by our own teams.
| Material and workmanship warranty with one party |
Installation crews, site method and workmanship are covered in depth on Waterproofing contractors in Colombo.
Where the site allows, we will still survey before confirming the figure. A photo shows the surface; it cannot show whether an old membrane has lost its bond underneath.
Granipierre Sandstone Finish
Per sft rate supply and application
LKR 6,220
Polyurea or a heavy-duty polyurethane with a wearing layer, installed by specialist crews with the right spray equipment.
