A horizontal life line system is only as reliable as its connection to the roof. On Indian industrial buildings, TsaF uses two families of roof fixing: screw-down roof posts for trapezoidal metal sheets, and clamp-on fixings that grip the seam of standing seam roofs such as Snap-lock, Kalzip and Klip-lock without piercing the sheet. Which one suits your roof is confirmed during the site survey, after the sheet profile and its condition have been checked.
Written by: Yatin Chaudhary, TsaF. Last updated: 24 October 2026.
Key takeaways
- The roof fixing is part of the engineered load path, not an accessory. Cable, brackets, posts and fixings are designed together.
- Trapezoidal sheets take screw-down roof posts that are fixed through the sheet into the profile and sealed.
- Standing seam roofs (Snap-lock, Kalzip, Klip-lock) take clamp-on fixings, so the sheet is not pierced.
- The seam or profile must be identified correctly, because the fixing has to match it.
- Sheet condition, roof warranty conditions and the routes to be covered all affect the fixing plan.
Why does the roof fixing matter?
In a fall, the load travels from the worker through the trolley into the cable, then through the intermediate brackets and end anchors into the roof posts, and finally through the fixings into the roof. Every link in that chain has to be suitable. A well-made cable on a fixing that does not match the roof is not a safe system.
That is why TsaF designs each horizontal life line system around the actual roof profile, the working routes and the number of users, rather than supplying a generic kit. The fixing decision comes early, alongside the choice between a fall-restraint and a fall-arrest layout, which is explained in our horizontal lifeline design guide.
Which roof types does TsaF fix to?
The table below summarises the two fixing families described on the TsaF horizontal lifeline product page. Other roof constructions are discussed at the survey stage.
| Roof type | TsaF fixing | Is the sheet pierced? | What to check first |
|---|---|---|---|
| Trapezoidal metal sheet | Screw-down roof posts fixed through the sheet into the trapezoidal profile | Yes, and the fixing is sealed | Sheet profile, thickness and condition; corrosion; leaks already present |
| Standing seam (Snap-lock, Kalzip, Klip-lock) | Clamp-on fixings that grip the standing seam | No | Exact seam system and profile; condition of seams and clips; roof manufacturer guidance |
How does screw-down fixing work on trapezoidal roofs?
Trapezoidal sheets are the most common metal roofs on Indian factories, warehouses and PEB buildings. Here the roof posts are fixed through the sheet into the trapezoidal profile and sealed. TsaF supplies anodised 6063 T6 aluminium roof posts in several footprints for end, corner and intermediate positions, so the post can be matched to the profile and height of the sheet.
Before a screw-down system is specified, the survey should establish:
- the sheet profile and thickness, and whether it is the original roof or a later overlay;
- the condition of the sheet around the planned post positions, including rust, damage or earlier repairs;
- any existing leaks, so they are not confused with new penetrations later;
- the location of rooftop plant, gutters, skylights and solar panels that the line must reach or avoid.
How does clamp-on fixing work on standing seam roofs?
Standing seam roofs are often chosen precisely because they have few or no through-fixings. For these roofs TsaF uses clamp-on fixings that grip the standing seam, so the sheet is not penetrated. The clamp has to suit the seam, so identifying the seam system is the most important step. Snap-lock, Kalzip and Klip-lock seams are not interchangeable.
Useful information for the survey includes the roof manufacturer and product name if known, close-up photos of a seam, and any roof warranty conditions that apply to attachments. If the seam type is uncertain, it is checked on the roof before the design is finalised.
Roof posts, brackets and layout
Whichever fixing is used, the rest of the system is common. A Ø8 mm SS AISI 316L cable of 7×7 construction runs between end anchors, supported by SS-316 intermediate brackets, typically every 8 to 12 metres, and turned at corners by 90° corner brackets. The TSAF-100A integrated shock absorber cum tensioner keeps the cable tensioned, and the Glider-8 travelling trolley passes the brackets so the worker does not unclip. These values are indicative; project-specific values come from the datasheet and the design.
What should you send TsaF before the survey?
| Information | Why it matters |
|---|---|
| Roof sheet type, and manufacturer if known | Decides between screw-down and clamp-on fixing |
| Close-up photos of the sheet profile or seam | Helps identify the profile before the visit |
| Approximate age and condition of the roof | Flags repairs that may be needed first |
| Roof plan or PEB drawings | Lets the engineer plan routes, spans and corners |
| Locations of plant, fans, gutters, skylights and solar panels | Defines where the line must go |
| Roof warranty conditions for attachments | Avoids conflicts with the roof supplier |
| Number of people who will work on the roof at once | The line is designed for a set number of users |
You can share these through our site assessment form. If you are still comparing budgets, our article on horizontal life line system cost in India explains which factors change the price.
Common roof fixing mistakes
- Assuming any seam clamp fits any standing seam roof.
- Fixing to sheets that are already corroded or damaged without repairing them first.
- Ignoring the roof supplier’s warranty conditions for attachments.
- Planning the line before deciding whether restraint or arrest is needed and checking clearance.
- Covering the routes but forgetting fragile skylights; see our skylight protection options.
Frequently asked questions
On standing seam roofs such as Snap-lock, Kalzip and Klip-lock, TsaF uses clamp-on fixings that grip the seam instead of piercing the sheet. On trapezoidal roofs the posts are screwed down into the profile and sealed.
The posts are sealed at the fixing. The survey also records any existing leaks, and the fixings are checked during the annual inspection.
Often yes, but the sheet condition is checked first. Corroded or damaged areas may need repair before posts are fixed.
Check the roof manufacturer or product name if available and share close-up photos of a seam. TsaF confirms the seam type on the roof before finalising the design.
Users should check the system visually before each use, and TsaF recommends a formal inspection at least once a year. The Annual Maintenance Check covers the line and its components.
TsaF designs, manufactures and installs each horizontal life line system for the roof it sits on. Request a site assessment to have your roof profile checked.
