Waterproof Cement Guide: Integral Waterproofing Admixtures, Cementitious Slurry Coatings, Mix Ratios, Uses for Tanks, Bathrooms and Basements, Limits on Cracks, Curing, Indicative Rates and Mistakes in Pakistan
Waterproof cement usually means ordinary cement mixed with a waterproofing admixture, or a ready cementitious slurry coating, which makes plaster and concrete resist water. It is widely used in tanks, bathrooms and basements. Admixtures cost from about PKR 300 per kilogram to PKR 1,000, and coatings about PKR 40 to 80 per square foot. This page covers integral waterproofing admixtures, cementitious slurry coatings, mix ratios, uses for tanks, bathrooms and basements, limits on cracks, curing, indicative rates and mistakes. For related pages see roof sealants, Sika Pakistan notes and bathroom leakage treatment.
What it is
There is no special cement that is waterproof by itself. Waterproof cement work uses an admixture added to the mix to reduce porosity, or a cementitious slurry brushed on in coats. Both make a dense layer that resists water pressure, but they are rigid and do not bridge moving cracks.
Indicative rates
These ranges show common figures.
| Item | Indicative range |
|---|---|
| Powder admixture, per kg | PKR 300 - 900 |
| Liquid admixture, 5 litre | PKR 2,500 - 6,500 |
| Cementitious slurry coating, 20 kg | PKR 6,000 - 14,000 |
| Applied coating, per sq ft | PKR 40 - 80 |
| Mason labour, per sq ft | PKR 20 - 50 |
Prices move with brand, model, size and stock. Use these ranges to judge a quote, then compare the exact model and what is included.
Mix ratios
Follow the maker's dose, commonly 1 to 2 percent of cement weight for powders or 1 litre per 50 kilograms of cement for liquids. Over-dosing weakens the mix. Use clean sand and the correct water-cement ratio, and mix thoroughly.
Where it works
It suits water tanks, bathroom floors and walls under tiles, basement walls, retaining walls and swimming pools. It is not suited to roofs that move and crack, where an elastic coating is better. See roof sealants.
Limits on cracks
Rigid cementitious layers crack if the structure moves. Treat existing cracks first with a flexible sealant or a crack-bridging layer, and use flexible products in joints. A hairline crack in a slurry coat will leak.
Application and curing
Wet the surface, apply two or three coats of slurry, each at right angles to the last, or plaster with the mix at 12 to 20 millimetres, and cure by keeping it damp for at least 3 to 7 days. Fill tanks only after curing. Plumbing and waterproofing work should be done by trained tradespeople and tested before it is covered.
What to check before buying
- Product. Rated for the use
- Dose. As per the data sheet
- Cracks. Treated first
- Curing. At least 3 to 7 days
Before you decide
Use a proper admixture or slurry at the right dose, treat cracks first and cure well. Waterproof cement is cheap and effective for tanks, basements and bathrooms when applied by the book. Test a new tank by filling it for 48 hours and marking the water level before use, and keep the product bags to show the brand and batch.
Frequently Asked Questions
Cement mixed with a waterproofing admixture, or a cementitious slurry coating, that makes plaster and concrete resist water. Ask for the specification in writing so you can compare quotes on the same basis. Check the warranty terms and who honours them before you pay.
As indicative ranges, powder admixture is about PKR 300 to 900 per kilogram and applied slurry coating about PKR 40 to 80 per square foot. Check the warranty terms and who honours them before you pay. Measure carefully and confirm sizes with the seller before ordering.
In tanks, bathrooms, basements and pools. Measure carefully and confirm sizes with the seller before ordering. Rates and stock change, so confirm the current position before you commit. If you are unsure, send a photo and the measurements and we will advise.
Moving cracks, over-dosing and poor curing. Rates and stock change, so confirm the current position before you commit. If you are unsure, send a photo and the measurements and we will advise. Ask for the specification in writing so you can compare quotes on the same basis.
At least 3 to 7 days. If you are unsure, send a photo and the measurements and we will advise. Ask for the specification in writing so you can compare quotes on the same basis. Check the warranty terms and who honours them before you pay.
Usually the same working day once you send the quantity, the size or rating and a photo. The reply is a written rate with the model, warranty and delivery listed, so you can compare it against other quotes line by line. Rates and stock change, so confirm the current position before you commit.
Planning waterproof work?
Send the details and a photo. We reply with a written rate.