Which Roofs Can Take Solar Panels Metal / Tile / Concrete
Most Thai roofs can take solar — metal sheet, CPAC concrete tile, clay tile, corrugated zinc and concrete flat roofs — they differ in the 'mounting method' and the 'leak risk'. This page covers how each type mounts, which roofs are risky or can't be used, and which way and what tilt to face.
Almost any Thai roof can take solar — they differ in how the array is fixed: standing-seam metal sheet clamps on, often with no drilling; tile (CPAC / clay) uses roof hooks slipped under the tile and bolted to the rafters; a concrete flat roof / rooftop deck uses a ballasted, tilted frame. Roofs to be careful with or avoid are asbestos tile, old/rotten or under-strength structure, heavily shaded roofs, or a too-flat roof (<10°). In Thailand, face the panels south and tilt them about 10–18° for the best output and so rain rinses off dust. The key detail is proper flashing/sealing at every fixing point.
How does mounting differ on metal-sheet / tile / zinc roofs?
| Roof type | Mounting method | Drilling? | Leak risk / caution | Difficulty |
|---|---|---|---|---|
| Metal sheet (standing seam) | Clamp on the seam | Usually none | Low (no penetration) | Easy |
| Metal/zinc, trapezoidal-corrugated | Hook/screw to purlin + seal | Drill + seal screw holes | Medium — seal well; check rust on old zinc | Medium |
| Concrete tile (CPAC) | Roof hook under tile, to rafter | Bolt hook to frame (tile not drilled) | Medium — seat tiles flush | Medium |
| Clay / ceramic tile | Special hooks, may grind/cut tile | Bolt to frame | Higher — brittle tiles crack = leaks | Hard (skilled installer) |
| Concrete flat roof / deck | Ballasted, tilted frame | Little/none + waterproofing | Low if no drill; else waterproof deck | Medium (free tilt) |
Solar mounting by roof type
Which roofs can't take solar / will it leak?
Which way should solar panels face, and at what tilt, in Thailand?
| Direction / angle | Relative output | Recommendation |
|---|---|---|
| Facing south | ~100% (best) | First choice where possible |
| East / West | ~85–90% | Fine — spreads output; good for TOU |
| Facing north | Lowest | Avoid if you can |
| Tilt angle | ~10–18° | ≥~10–15° so rain rinses + drains |
Putting solar on your roof, step by step (5 decision steps)
Before the real install, work through these 5 steps to pick the right, leak-free approach:
Identify the roof material, match the mounting kit
Metal sheet = clamp/hook; tile = roof hook; flat deck = ballast — the wrong kit for the material is the number-one cause of leaks.
Assess the structure / load-bearing
Check the roof's age, the rafters/purlins, and the ~15–20 kg/m² it adds — if the roof is old or you're unsure, have an engineer check first.
Pick orientation and tilt, avoid shade
Face south at ~10–18° if you can; survey shade from trees/buildings/tanks across the day and lay out the array to dodge it.
Flash and seal every fixing
Every fixing/penetration needs correct flashing and sealant for the roof type, standard-grade hardware, and no standing on brittle tiles.
Sign-off + paperwork/permits
Test for leaks after install, keep the workmanship warranty, and complete the permit / grid-interconnection filing with the utility.
Before you install: 5 roof things you can't skip
Panels live on the roof for 25 years — check these 5 before you decide:
Roof age / condition
If the roof is near end-of-life or already leaking, repair/replace it before installing — otherwise you'll have to remove the panels to fix it later, paying twice.
Load-bearing structure
Rafters, purlins and posts must carry the panel + mount (~15–20 kg/m²) plus wind load; have an engineer look at older or extended houses.
Shading
Trees, neighbouring buildings, water tanks, antennas — even partial shade drops a whole string's output and risks hotspots; survey shade across the day.
Waterproofing & workmanship warranty
Ask the installer what flashing they use and about the workmanship/leak warranty; put in the contract who is responsible if it leaks.
Usable roof area
Deduct the wrong-facing slopes, skylights, pipes, vents and edge setbacks — the truly usable area sets how many kW you can fit.
Complex roof, a building, or a factory?
Author & review
Written and reviewed by the CapSolar engineering team (rooftop solar EPC), citing installation practice and engineering standards (EIT / วสท) alongside utility knowledge sources (PEA Solar / MEA / SafeSaveThai). Tilt/orientation follow solar geometry; load figures are typical values — last verified 23 Aug 2026.
FAQ
Want to know how many kW your roof can fit?
Send CapSolar a roof photo or house plan and we'll assess the roof type, mounting, orientation-tilt and the right install size.