FLAT ROOF (COMPOSITE SLAB) VS PITCHED ROOF – WHICH IS MORE AFFORDABLE?
Many Kenyans automatically assume a pitched roof is cheaper because it is what we have grown up seeing. But when you break down the actual costs, the story changes.
📸 The house in the picture uses a flat composite slab roof, creating usable rooftop space for solar panels, water heating and future expansion.
🔳 Composite Slab Roof
Average cost:
✅ Sh 3,700 – 4,000 per m² (transport included)
This includes:
* Prestressed T-beams
* 1 meter Hollow core infill panels
* FRC Concrete topping
* Roof structure ready for waterproofing
Additional cost:
* Elastomeric waterproofing: approximately Sh 1,000 per m²
Benefits:
✔ Creates usable roof space
✔ Ideal for solar panels and solar water heaters
✔ No timber required
✔ No ceiling required underneath
✔ Minimal maintenance
✔ Modern architectural finish
✔ Future vertical expansion possible
🔳 Pitched Roof
Average cost:
✅ Sh 7,000 – 10,000 per m² depending on pitch .
This includes:
* Timber trusses ( takes the big share of cost )
* Roofing sheets / stone-coated tiles
* Fasteners
* Insulation
* Ceiling framework
* Ceiling boards
* Labour
Challenges:
❌ Large timber consumption
❌ Ceiling required
❌ Insulation required
❌ Roof space mostly unusable
❌ Higher maintenance over time
The Math
For a 100 m² roof:
🔳 Composite Slab
* Roof structure: Sh 370,000 – 400,000
* Waterproofing: Sh 100,000
Total: Sh 470,000 – 500,000
🔳 Pitched Roof
* Average: Sh 700,000 – 1,000,000
Difference: You could save hundreds of thousands of shillings while gaining a usable roof deck.
In Africa, we do not design roofs to carry snow loads. The question many homeowners should ask is:
Why spend more money building empty attic space when the same funds can create a solid roof that harvests solar energy, supports water heating, and gives you additional usable space?
Engage Floor Decor Kenya
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