If there is one part of a Tricity building that leaks more than any other, it is the terrace. Flat roofs collect standing water, bake under the sun, and expand and contract with every big temperature swing. Sooner or later that movement opens up cracks, and the next monsoon sends water straight into the rooms below.
The good news is that a properly waterproofed terrace can keep water out for years. This guide covers why terraces leak, the coating options we stock from Dr. Fixit and Sika, and the step-by-step method for doing the job well. For where terrace work fits in the bigger picture, see our complete waterproofing guide for Panchkula. If water is already coming through, start by stopping the active leak first.
Why terraces leak in the Tricity
Panchkula, Chandigarh and Mohali put terraces through a hard cycle: a heavy monsoon followed by long, hot, dry spells. A few things combine to cause leaks:
- Standing water. Flat or poorly sloped terraces hold water instead of draining it, and standing water finds every weak point.
- Thermal movement. The concrete expands in the heat and contracts as it cools, which slowly opens hairline cracks.
- UV exposure. Constant sun degrades unprotected surfaces and older coatings.
- Poor detailing. Junctions where the terrace meets parapet walls, drains and pipes are common entry points when they are not sealed properly.
Good terrace waterproofing deals with all of these: a flexible coating that can bridge cracks, laid over a surface that is prepared and sloped to drain.
The two coating families for terraces
Most terrace waterproofing products fall into one of two groups. Knowing the difference makes it easier to choose.
Cementitious flexible coatings
These are usually two-component products: a cement-based powder mixed with an acrylic polymer liquid. They bond strongly to concrete, resist water pressure well, and stay flexible enough to handle minor movement. Dr. Fixit Pidifin 2K and Fastflex sit in this group.
Acrylic elastomeric coatings
These are liquid-applied, highly elastic membranes that cure into a seamless, rubbery film. They are very good at bridging cracks and standing up to UV, and many are trafficable, meaning you can walk on them. Dr. Fixit Roofseal Select, long known as Newcoat, is the familiar example.
For many terraces a combination works best, but either family, applied correctly, gives a reliable result.
Dr. Fixit and Sika terrace products we stock
Here is a quick orientation to the products, so you know what does what:
- Dr. Fixit Pidifin 2K: a two-component, acrylic-modified cementitious coating. Flexible and durable, it suits terraces, water tanks, bathrooms and pools, forming a strong waterproof barrier on concrete and masonry.
- Dr. Fixit Fastflex: a high-performance flexible coating for terraces, balconies, roofs and podiums. A Fastflex Ultra version is available where faster drying is needed.
- Dr. Fixit Roofseal Select (formerly Newcoat): a heavy-duty, reinforced, trafficable acrylic membrane. It is highly elastic, UV-resistant, and can bridge cracks up to around 2 mm. Applied as a multi-coat system, it can go over existing sound treatments like brickbat coba and screeds.
- Sika: the Sikalastic range of liquid-applied membranes, often specified on larger or commercial roofs and refurbishment jobs, gives a seamless, elastic and UV-resistant finish.
We stock the Dr. Fixit and Sika waterproofing chemicals for terrace and roof work. Tell us the area and the condition of your terrace and we will help you pick the right product and quantity.
How to waterproof a terrace step by step
Whichever coating you use, the method follows the same logic. Preparation and detailing matter as much as the coating itself.
1. Prepare the surface
Clean the terrace thoroughly. Remove dust, loose material, old flaking coating, oil and algae. The surface must be sound, because a coating is only as good as what it sticks to.
2. Treat cracks and junctions
Fill and seal cracks. At the junctions where the floor meets parapet walls, and around drains and pipes, form a rounded fillet (called coving or haunching) so water does not sit in a sharp corner. Reinforce cracks and junctions with fibre mesh where the product calls for it.
3. Sort out the slope and drainage
Water must be able to run off to the drain points. If the terrace holds water, correct the slope before coating, or the standing water will keep testing the membrane.
4. Prime if required
Some systems need a primer for better adhesion. Follow the product datasheet.
5. Apply the first coat
Apply the first coat evenly across the whole surface and let it dry as directed.
6. Apply the second coat
Apply the second coat at right angles to the first. Working in the cross-direction gives even coverage with no thin spots. For large roofs, embed a reinforcing fabric between the coats for extra strength.
7. Cure and test
Let the coating cure fully. Before putting the terrace back into use, do a ponding test: fill the area with water to around 50 mm and leave it for a day or two, then check the rooms below for any sign of leakage. Only once it passes is the job done.
Working over old brickbat coba
Many older Tricity terraces already have a brickbat coba layer. You do not always have to remove it. If it is sound, a membrane such as Roofseal Select can be applied over it after proper cleaning and preparation. If the coba is badly damaged or holding water, it is better to repair or redo the base first. When in doubt, ask us or have it inspected.
When to waterproof, and when to call a professional
The best time to waterproof a terrace is before the monsoon, on a dry surface, in dry weather, so the coating can cure without rain interrupting it. A small, sound terrace is within reach of a careful DIYer. Large terraces, badly damaged surfaces, and roofs with complex detailing are better handled by an experienced applicator, and we can supply the materials either way.
Common mistakes to avoid
- Coating over a dirty or damp surface. Poor preparation is the number one reason coatings fail.
- Ignoring the slope. No coating enjoys sitting under permanent standing water.
- Skipping junction detailing. Most leaks start at parapet joints, drains and pipe penetrations, not in the middle of the slab.
- Applying too thin. Follow the coats and coverage the datasheet specifies. Two proper coats beat one thick, uneven one.
- Not doing a ponding test. Test before you trust it, not after the next rain.
Terrace waterproofing materials in Panchkula
Planning to waterproof a terrace or roof this season? Bring us the area and a photo of its condition, and we will recommend the right Dr. Fixit or Sika system and the quantity you need. Khandelwal Trading Co. serves Panchkula, Chandigarh, Mohali and the wider Tricity.
- Visit: Shop No. 4, Street No. 2, Maheshpur, Sector 21, Budanpur, Panchkula, Haryana 134117
- Call: 94175 65977
- WhatsApp: message us here
- Trade enquiry: get a quote
Frequently asked questions
What is the best coating for terrace waterproofing?
It depends on the terrace. A flexible cementitious coating like Dr. Fixit Pidifin 2K or Fastflex works well on most, while an acrylic elastomeric membrane like Roofseal Select is strong on crack-bridging and UV resistance. Whichever you choose, surface preparation and proper slope matter just as much as the product.
How many coats does a terrace need?
Usually at least two, with the second applied at right angles to the first for even coverage. Large roofs often need a reinforcing fabric embedded between coats. Always follow the coats and coverage on the product datasheet.
Can I waterproof over an existing brickbat coba?
Yes, if the coba is sound. After thorough cleaning and preparation, a membrane can be applied over it. If the coba is damaged or holding water, repair or redo the base first.
How do I know the waterproofing has worked?
Do a ponding test once the coating has cured. Fill the terrace with water to about 50 mm, leave it for a day or two, and check the rooms below for any leakage. If they stay dry, the job has passed.
When should I waterproof my terrace?
Before the monsoon, on a dry surface, in dry weather, so the coating can cure without rain. Waterproofing during the rains rarely lasts.
