Once a client has decided on a retractable roof, the next question is what the roof is made of. The two practical choices are rigid polycarbonate panels that slide, and a tensioned fabric membrane that folds back. They behave differently enough that the space itself usually decides. Both materials are covered in context on the retractable roofs page.
How the two behave
01Daylight
Polycarbonate transmits light, so a closed roof still feels bright and the space below reads as a conservatory. Fabric blocks direct sun and gives shade; closed, the space reads as a covered room.
02Heat
Daylight brings warmth with it. Under polycarbonate in a Delhi summer afternoon the space heats up unless it is ventilated or shaded. A fabric membrane keeps direct sun off entirely.
03Rain noise
Rain is louder on rigid panels than on a tensioned membrane. Over a bedroom terrace or a restaurant that is a real consideration; over a car park it is irrelevant.
04Weight and span
Fabric is lighter and folds on itself, which helps on longer openings and keeps manual operation comfortable further. Polycarbonate is heavier and reaches the practical manual limit sooner.
Where polycarbonate is the better choice
- Terraces and sit-outs that would feel like a cave under solid shade.
- Spaces where you want the glass-roof look while still being able to open it.
- Smaller openings, where the extra weight is not a problem.
- Where the roof stays closed most of the time and daylight matters more than heat.
Where fabric is the better choice
- Restaurants, banquet lawns and hotel courtyards where guests sit for hours.
- Swimming pools, where shade and UV control are the point.
- Larger openings, where weight and travel distance start to dominate.
- Anywhere the roof is opened and closed often, especially by hand.
Upkeep is not the same either
Both need cleaning, and both should be inspected before and after the monsoon. Polycarbonate panels are wiped down and the track kept clear of grit, which is what usually causes stiff operation. A membrane is washed down and checked for tension and for wear at the fixing points, and its life depends on the coating family chosen. Our maintenance guide sets out the schedule for membranes, and the materials guide explains how PVC, PVDF, PTFE and ETFE differ.
Questions worth answering before you decide
- Do you want daylight coming through the closed roof, or shade under it?
- Will people sit under it for hours, or pass through?
- Is the opening long and narrow, or close to square?
- Will it be opened by hand or by remote? Weight matters more for manual.
- Does rain noise matter for what happens below?
Common questions
Can the two be mixed on one structure?
Yes, on separate bays. A courtyard can have a fabric roof over the seating and a polycarbonate section over a walkway, provided each bay is engineered for its own material.
Which lasts longer?
Both are engineered products with a long service life, and both depend far more on installation quality and upkeep than on the material alone. A membrane's life tracks the coating family; a polycarbonate roof's tends to track its track hardware and fixings.
Does polycarbonate yellow over time?
Quality sheet carries a UV-protected face that resists it, and that face must be installed the right way up. This is one of the places where cheap sheet and careless installation show themselves early.
Which is better for an Indian summer?
For sitting under, fabric: it keeps direct sun off and the space cooler. For brightness in a smaller space you mostly pass through, polycarbonate is pleasant, provided the area is ventilated.
If the operation side is still open, read manual or motorised next, or send us photographs of the space.
More reading: Manual vs Motorised Retractable Roofs (which drive to choose) and What Drives Retractable Roof Cost (where the money actually goes). All posts are listed on the Ekra Decor blog.
How each one fails, which is not the same thing
Comparisons usually stop at how a material performs when new. What separates these two in practice is how they end.
Polycarbonate fails optically before it fails structurally. UV degradation yellows it and it loses clarity; a co-extruded UV-protected grade resists this for far longer than a cheap sheet, which is the single biggest variable in a polycarbonate quotation and the one most often left unstated. Twin-wall sheet has a second failure mode: if the flutes are not sealed properly at the ends, dust and moisture get inside them and no amount of cleaning will ever get it out.
Fabric fails at its surface and at its edges. The coating weathers, the membrane picks up dirt, and if it has been allowed to go slack it abrades where it passes over fixings. None of that is sudden, which is the useful part: a membrane approaching the end of its life looks tired for a long time before it is a problem.
On both, the thing to ask about is the grade, not the material. “Polycarbonate” covers sheet that will last a decade and sheet that will not; “fabric” covers plain PVC and PVDF-lacquered PVC, which do not age the same way at all.
Choosing late costs more than choosing differently
Because the two weigh very different amounts, the roofing decision is a structural decision, and it has to be made before the frame is designed rather than after.
Rigid sheet is heavier and needs more support underneath it - more purlins, closer centres, a heavier moving frame on a retractable roof. A membrane weighs almost nothing but pulls hard at its anchor points, so the frame is sized for tension rather than for carrying weight.
Swap one for the other after the steel is designed and you are not swapping a material. You are changing what the structure was engineered to do. On a retractable roof, where the frame also has to move, that is the difference between a drive system that is correctly sized and one that is working harder than it was meant to for the rest of its life.
The roof material is a structural decision made early, not a finish chosen late.
The honest summary
If the space is small, simple and rectangular, and the priority is a hard roof at the lowest sensible cost, polycarbonate in a properly UV-protected grade is a good answer and we will say so.
If the span is larger, if the roof will be seen and has to look like part of the building, if rain noise matters because people sit underneath, or if the weight of a rigid roof would drive the moving frame up a size, fabric earns its extra cost.
Most disappointment with either comes from choosing on headline rate and discovering the grade afterwards.