Rooftop Garden Ideas & Waterproofing Cost Sri Lanka (2025)
Rooftop Garden Ideas & Waterproofing Cost Sri Lanka (2025)
The concrete slab is a wasted asset.
In most Sri Lankan homes, the rooftop is just a place to dry clothes and water tank storage. It also absorbs massive heat, making the bedrooms below unbearable.
Turning it into a Rooftop Garden solves two problems: it gives you entertainment space and significantly cools your home.
Table of Contents
- The Golden Rule: Waterproofing First
- Design Ideas: Low Maintenance
- Heat Reduction Benefits
- Costing the Project
1. The Golden Rule: Waterproofing First
Do NOT place pots or soil on a slab without proper waterproofing. Leaks will destroy your structure.
The Process:
- Cleaning: Pressure wash the slab.
- Product: Apply cementitious waterproofing (Chemifix, Dr. Fixit, Sika).
- Protection: Lay a protective screed (thin cement layer) or tiles over it.
- Testing: Flood the slab with water for 48 hours to check for leaks.
Cost: Rs. 150 - 250 per sq ft (Material + Labor).
2. Design Ideas: Low Maintenance
Sri Lankan sun is harsh. Delicate flowers will die. Go hardy.
- The "Pot" Garden: Don't build permanent concrete beds (heavy!). Use large clay or plastic pots.
- Plants: Bougainvillea, Temple Trees (Frangipani), Palms, Sansevieria.
- The "Turf" Lounge: Artificial grass (astro turf) looks great and is soft to walk on.
- Cost: Rs. 250 - 450 per sq ft.
- The Covered Zone: You need shade for daytime use. A simple Pergola with passion fruit vines or a canvas shade sail.
3. Heat Reduction Benefits
A bare concrete slab hits 60°C at noon. A garden-covered slab stays around 35°C.
This massive reduction means your bedrooms below stay cooler, reducing A/C costs by 20-30%. The "green roof" acts as insulation.
4. Costing the Project (500 sq ft Terrace)
| Item | Cost |
|---|---|
| Waterproofing | Rs. 100,000 |
| Artificial Grass (300 sq ft) | Rs. 100,000 |
| Pots & Plants | Rs. 50,000 |
| Outdoor Lighting (String lights) | Rs. 15,000 |
| Outdoor Furniture (Rattan) | Rs. 60,000 |
| TOTAL | Rs. 325,000 |
Verdict: For Rs. 3-4 Lakhs, you gain a brand new "living room" under the stars.
Find a view worth enjoying: Lands with views