The short version
| Metal deck (colour-coated steel) | Concrete tile (genting) | |
|---|---|---|
| Installed cost | RM8–14/sq ft (RM14–22 insulated) | RM25–45/sq ft incl. battens |
| Weight | Very light — no structural upgrade | Heavy — trusses must be rated for it |
| Heat | Hot unless insulated (PU foam or reflective coating) | Better thermal mass; cooler evenings |
| Rain noise | Loud unless insulated / ceiling insulated | Quiet |
| Lifespan | 20–30 years (coated); zinc much less | 40–50+ years for the tiles; battens 25–40 |
| Leak points | Fixings and laps | Individual tiles, ridges, valleys, flashings |
| Repairability | Sheet replacement; rust is terminal | Tile-by-tile; very repairable |
| Install time (terrace) | 2–4 days | 5–10 days |
| Look | Modern / industrial; limited profiles | Traditional; many profiles and colours |
When metal deck is the right call
- The existing tiles and the timber underneath are shot and you're paying for a full strip anyway.
- The roof structure is marginal — old timber, or an extension with light steel — and can't be trusted with tile weight.
- It's a shoplot, factory, kitchen extension or car-porch roof where look and noise matter less.
- You want it done in days, not weeks. Budget for the insulated version: plain metal deck on a west-facing bedroom is a decision people regret in April.
When to keep the tiles
- The tiles are sound and the problem is battens, sarking, ridges or flashings. A re-lay reusing your tiles (RM25–45/sq ft) keeps the cool, quiet roof and the look.
- A heritage or matching-the-neighbours situation on a terrace row.
- You plan to stay 20+ years — tiles outlast coated steel.
The heat question, honestly
Bare metal deck radiates heat into the roof space and is noticeably hotter than tile by mid-afternoon. PU-foam-backed deck (25–50mm) largely fixes this and cuts the rain noise; reflective roof coatings help; ceiling insulation helps whichever roof you have. If the budget only stretches to plain metal deck, add ceiling insulation.
Want both quoted? We'll price a re-lay and a metal deck re-roof side by side after inspection. See the cost guide for the ranges.