Solar Mounting Structures and Roof Safety Basics (India)
If you’re planning a rooftop solar system, the panels are only as reliable as two things: the mounting structure and the roof underneath it. A good structure keeps your modules secure through wind, rain, and heat cycles. A safe roof setup ensures installers can work without accidents and your building doesn’t develop leaks or cracks later.
A safer rooftop solar system starts with the right mounting and roof access—think wind safety, corrosion protection, and clear walkways.
This guide covers mounting structure basics + roof safety essentials for typical Indian rooftops.
Why mounting + roof safety matter more than people think
On rooftops, problems usually don’t start with the solar panel. They start with:
- Poor anchoring (wind uplift loosens bolts)
- Rust/corrosion (especially coastal and industrial areas)
- Bad waterproofing (drilling + no sealing = leaks)
- No access paths (cleaning becomes unsafe, shortcuts happen)
Indian regulations also push for safe roof access and walkways for rooftop systems. For example, the Central Electricity Authority (CEA) safety rules include clear roof pathways (minimum 75 cm) with handrails for access and emergency exit, and walkways between rows/columns for cleaning and maintenance.
Types of solar mounting structures used on Indian roofs
1) Anchored (bolt-fixed) structures
Most common on RCC terraces and some sheet roofs (with correct fasteners).
Pros
- Strong against wind uplift
- Lower weight than ballast systems
Cons
- Requires drilling (waterproofing must be done properly)
2) Ballasted (non-penetrating) structures
Used when you want to avoid roof penetration (common on waterproofed terraces).
Pros
- Minimal drilling into roof slab/waterproof layer
- Faster installation on some roofs
Cons
- Adds significant dead load (must be structurally checked)
- Wind design is still critical (ballast sizing is not guesswork)
3) Elevated “high-rise” structures
Used to clear parapets/shadows or to keep the array above utility lines/tanks.
Pros
- Better shade avoidance in tight roofs
Cons
- Higher wind moment → structure design must be stronger
- Needs excellent bracing and anchoring
What a good mounting structure is made of
A rooftop solar structure is not just “metal frames.” It’s a system:
- Base supports / feet (L-feet, standoffs, roof clamps)
- Rafters / purlins / rails
- Mid clamps & end clamps
- Bracing members (especially for elevated structures)
- Fasteners (stainless steel preferred for bolts/nuts/washers)
- Earthing bonding points (structure must be electrically bonded)
Material choice: Aluminium vs Galvanised steel
A common best practice in rooftop QC manuals is:
- Steel structure: should be hot-dip galvanized
- Aluminium structure: should be anodized
…with coating thickness appropriate for corrosion protection.
Also: avoid practices that damage protective coating. Some rooftop QC guidance specifically warns against drilling/welding/cutting at site because it damages coating and accelerates corrosion, and discourages using mild-steel accessories that rust quickly.
Practical tip (India):
- Coastal cities (Chennai, Mumbai, Kochi, Vizag) and industrial belts need extra corrosion resistance: better coatings, stainless fasteners, and careful separation of dissimilar metals to reduce galvanic corrosion.
Wind safety basics (the part many rooftops get wrong)
On rooftops, wind doesn’t just “push”—it can lift panels like a wing. That’s why the mounting system must be designed for local wind conditions.
Quality manuals for rooftop solar in India explicitly reference designing PV mounting structures as per IS 875 (Part 3) Wind Loads, and also note keeping adequate gaps/access when modules are installed on inclined roofs so maintenance personnel can reach corners safely without stepping on modules.
What you should insist on (even as a homeowner)
- Your EPC should confirm the design basis references IS 875 Part 3 for wind loading.
- Edge/corner zones of the array should have stronger fastening (wind is highest here).
- Elevated structures need more bracing than low-profile frames.
- “Standard structure” without site wind consideration is a red flag.
Roof safety basics before installation
Step 1: Check roof type and condition
RCC terrace (most common):
- Look for cracks, seepage, spalling, loose parapet coping.
- If waterproofing was done recently, decide whether you want penetrations or ballast.
Metal sheet roofs:
- Use correct clamps/fasteners for the profile.
- Avoid weak areas near sheet overlaps; fasten to purlins/structural members.
Old asbestos-cement roofs:
- These are fragile and hazardous to disturb. In many cases, replacement with a safer roofing solution is smarter than mounting directly.
Step 2: Do a basic load sanity check
Even small residential systems add load:
Panels + structure + ballast (if used)
People walking during installation/maintenance
If the roof is old, has visible distress, or you plan a ballasted system, get a civil/structural review (especially for large terraces and old buildings).
Step 3: Plan access, walkways, and working space
Roof access and safe movement are not optional “nice-to-haves.” CEA safety requirements include:
- Clear pathways at least 75 cm wide with handrails for roof access and emergency exit (for rooftop systems).
- Clear walkways between rows/columns for cleaning and maintenance.
Practical layout tips
- Keep at least one clear service corridor from access point to inverter/ACDB area.
- Don’t block water tanks, dish antennas, vents, or staircase headroom.
- Ensure you can reach every panel row for cleaning without stepping onto modules.
Waterproofing: how to avoid leaks (biggest rooftop solar complaint)
Leaks usually come from:
- Drilling into the slab/waterproof layer
- No proper sealing
- Loose fasteners over time
Good practice checklist
- Use proper roof anchors/chemical anchors where suitable.
- Use UV- and weather-resistant sealants.
- After mounting, do a water test around penetrations (where feasible).
- Avoid random on-site cutting/welding that damages protective coatings and increases corrosion risk.
If your roof has premium waterproofing (PU/APP membranes), discuss non-penetrating options or mounting methods that protect the membrane.
Earthing and bonding: safety meets structure
Even though this post is about mounting and roofs, one point overlaps strongly with safety: the structure must be earthed.
CEA safety requirements include earthing of PV module mounting structures, inverters and control systems along with other non-current-carrying metal parts.
Also, CEA mentions that DC cable should be UV protected or routed through UV-protected pipe (important for rooftop cable runs exposed to sunlight).
Installer safety basics (what should be happening on your roof)
Even homeowners benefit from knowing what “safe work” looks like:
- Non-slip shoes + gloves
- Harness and lifeline where fall risk exists
- No working during high wind/rain
- Clear roof edges and safe ladder access
- No stepping on modules (microcracks are real)
A well-planned system layout (walkways + access) reduces unsafe shortcuts long-term—especially during cleaning.
Quick inspection checklist (before you approve installation)
Mounting structure
- Corrosion protection: HDG steel / anodized aluminium
- Stainless fasteners, no cheap mild-steel accessories
- Wind design basis references IS 875 Part 3
- No unnecessary on-site cutting/welding that damages coating
Roof safety + access
- 75 cm clear pathway with handrails for access/emergency exit
- Walkways between rows/columns for cleaning
- Waterproofing approach defined (penetrating vs ballasted)
- Drainage not blocked; slope/water flow maintained
Safety bonding
- Mounting structure bonded/earthed
- UV protection for exposed rooftop DC wiring
Common mistakes to avoid (India rooftop reality)
- “Standard structure” copied from another site without wind consideration
- Rust-prone hardware (mild-steel bolts, low-grade coatings)
- No maintenance access (panels packed wall-to-wall)
- Penetrations without waterproof detailing
- Structure not bonded/earthed, creating safety risk
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