How to Replace a Walk-In Greenhouse Cover

On this page (10 sections)

1. How do you know when a greenhouse cover needs replacing?
2. What should you measure for a replacement greenhouse cover?
3. When does a tunnel greenhouse cover make sense?
4. How do you choose between PE and PVC?
5. How do you remove the old cover safely?
6. How do you fit a replacement greenhouse cover?
7. How tight should the cover be?
8. What should you check after installation?
9. What mistakes can damage a new cover?
10. Which replacement greenhouse cover should you choose?

A replacement greenhouse cover should match your frame's dimensions, shape, door position, and attachment points. For compact walk-in frames, several 56 x 56 in covers are available; a much larger tunnel cover needs a different structure.

Measure the frame before you buy, and check for damage that could tear the new cover. If the old cover is still in place, take photos of how its door, edges, and fasteners meet the frame.

How do you know when a greenhouse cover needs replacing?

Replace a greenhouse cover when tears, loose seams, cloudy sections, or failed fasteners stop it from fitting or protecting plants as intended. Small damage may be repairable, but a cover that repeatedly pulls loose or leaves large gaps is a poor barrier.

Check the seams, corners, zipper, windows, and places where the cover touches the frame. Look for brittle material, torn tie points, and openings that return after you secure them.

Inspect the frame at the same time. A bent pole, loose connector, or sharp edge can damage a new cover, so correct the cause before installing one.

What should you measure for a replacement greenhouse cover?

Measure the frame's length, width, and height at the widest points, then compare them with the cover's dimensions. Also compare its shape, door position, and fasteners because covers with similar dimensions may fit different frame layouts.

Measure the frame rather than relying on an old cover that may have stretched or sagged. Note whether the roof is peaked, rounded, or sloped, and check where the entrance sits.

A compact walk-in frame and a tunnel greenhouse need different shapes. For an overview of the options, see our backyard greenhouse guide.

Will a 56 x 56 x 76 in replacement greenhouse cover fit?

A 56 x 56 x 76 in replacement greenhouse cover may suit a compact walk-in frame with matching dimensions and layout. The size alone doesn't confirm that the zipper, corners, and attachment points will line up.

TENTOPMIC's PE cover is 56 x 56 x 76 in, has a roll-up zipper door, and doesn't include a frame. Its extended edges can be anchored with stones.

SHANGXING's PE cover is slightly larger at 56.3 x 56.3 x 76.8 in. Choose it only if those dimensions and its openings fit your frame; its cover also comes without a frame.

DECOHS uses clear PVC in a 56 x 56 x 76 in cover with a roll-up zipper door. It may suit a matching frame if you prefer PVC, but skip it if your frame needs another size, shape, or attachment layout.

Both PE options suit gardeners who want a cover in this compact size with a roll-up door. The PVC option gives you a different cover material at nearly the same dimensions.

None includes a frame, so these are replacements for an existing compatible structure.

For a closer look at the material trade-offs, read PE vs PVC greenhouse cover. If your structure uses flat sheets instead of a fitted cover, compare options in our greenhouse plastic sheeting guide.

When does a tunnel greenhouse cover make sense?

A tunnel cover makes sense when you have a matching hoop-house frame, not a compact walk-in frame. The BPS cover measures 10 x 7 x 7 ft and is made of PE.

Its six roll-up windows have mesh panels, and the cover has internal straps, D-ring retainers, and weighted edges for securing it. These features suit a gardener replacing a cover on a compatible tunnel structure who needs multiple ventilation openings.

Skip it if your frame is a compact walk-in model or if you can't confirm the frame dimensions and fastening layout. Its larger size doesn't make it a substitute for a small fitted cover.

How do you choose between PE and PVC?

Choose by matching the replacement material to your needs and checking that it fits your frame. The compact PE choices are close in size, while the PVC option has a similar footprint with a different material.

TENTOPMIC and SHANGXING describe their PE covers as waterproof and UV resistant. DECOHS describes its PVC cover the same way.

These claims don't change the main fit check: the corners, openings, and fasteners still need to line up.

A roll-up zipper door provides access and can be opened for airflow. The tunnel option adds six roll-up mesh windows, so it fits a different ventilation setup from the compact covers.

Don't choose by material name alone. For more on how PE and PVC differ as greenhouse covers, use the material comparison guide.

How do you remove the old cover safely?

Remove the old cover after clearing the work area and checking that the frame is stable. A calm, dry day makes loose material easier to handle than a windy one.

Move pots, tools, and shelves away from the frame. Temporarily move plants that could be bumped while you work, and keep a clear path around the structure.

Open zippers and release ties or fasteners gently. Don't pull against a pole or connector; a sudden tug can shift a light frame or damage a joint.

As you remove the cover, note how its edges and openings sit. Photos can help you remember the door orientation and the path of ties or clips.

How do you fit a replacement greenhouse cover?

Fit the new cover with the door and roof aligned, then secure it evenly around the frame. Keep the material centered as you work so one corner or seam doesn't take all the tension.

1. Confirm that the frame is assembled, stable, and free of sharp edges.
2. Unfold the cover and locate its door, roof, and any windows.
3. Point the door toward the frame entrance before pulling the cover on.
4. Work the cover over the frame without snagging it on connectors.
5. Align the corners and edges, then attach the fasteners as designed.
6. Check the zipper and openings before tightening the remaining fasteners.

If you have a small walk-in cover with extended edges, position them as intended before weighing them down. TENTOPMIC says its edges can be anchored with stones.

Follow the instructions for your cover and frame, since attachment methods differ.

Don't stretch a cover hard to force a mismatch. If the corners, door, or attachment points won't align, stop and check the dimensions and frame layout again.

How tight should the cover be?

The cover should sit evenly and resist loose flapping without straining its seams or bending the frame. Secure opposing sides a little at a time to keep it centered.

Walk around the greenhouse as you work. If one side is taut while another hangs loose, adjust the fit before tightening further.

For tunnel covers, use the supplied design features as intended. The BPS cover has straps, D-ring retainers, and weighted edges; those are useful on a compatible frame, but they can't correct a size or shape mismatch.

What should you check after installation?

After fitting the cover, run the zipper through its full path, inspect the seams, and check that the edges stay attached. Confirm that the frame is steady and ventilation openings are clear.

Look around the structure for loose sections, sharp creases, and gaps near the ground. Check that doors and windows can open and close before returning shelves and plants.

Secure the greenhouse according to its frame and cover instructions. Our guide to anchoring a pop-up or walk-in greenhouse explains ways to stabilize a lightweight structure.

What mistakes can damage a new cover?

The most common mistakes are buying by the “walk-in” label alone, forcing a poor fit, and leaving frame damage unfixed. Each can cause trouble even when the replacement seems close in size.

• Using only the old cover's measurements: Stretching and sagging can make it a poor guide. Measure the frame.
• Ignoring the door and roof shape: A cover can have similar dimensions but openings in the wrong places.
• Pulling hard on a tight corner: This can strain the seam or shift the frame.
• Leaving sharp edges exposed: Smooth or repair contact points before adding the new material.
• Closing every opening: A cover with a roll-up door or windows needs those openings managed for airflow.

A plastic sheet isn't automatically a fitted greenhouse cover. If you want sheet material, plan its cutting and fastening separately, and check whether your frame needs a door or ventilation openings.

For rigid sections, see our guide to polycarbonate greenhouse panels.

Which replacement greenhouse cover should you choose?

Choose the 56 x 56 x 76 in TENTOPMIC or DECOHS cover if your compact walk-in frame matches and you want PE or PVC, respectively. Consider SHANGXING if its slightly larger dimensions fit your frame.

Choose BPS only for a matching 10 x 7 x 7 ft tunnel frame.

Skip all four if your frame dimensions, openings, and attachment points don't match, or if the frame itself needs repair. Measure first, compare the cover shape, and use our walk-in greenhouse setup guide if you need help checking the structure.

Frequently asked questions

How do I measure for a replacement greenhouse cover?

Measure the frame's length, width, and height at its widest points, then compare those measurements with the replacement cover's dimensions. Check the roof shape, door position, and fastening points, too.

A cover with similar dimensions may be designed for a different frame layout.

Confirm that its openings and attachment points align before removing the old cover.

Can I put a PE cover on a greenhouse made for PVC?

Possibly, if the replacement has the right dimensions and attachment layout, but material alone doesn't guarantee a fit. Compare the frame shape, door position, and fastening points.

Read our guide to PE vs PVC greenhouse covers to compare the materials.

Can I replace a greenhouse cover without taking the frame apart?

Often, you can fit a replacement over an assembled frame, but the cover design and working space affect the job. Follow its instructions, and get help if the frame is unstable or awkward to reach.

Don't force a cover over sharp edges or bent supports.

How often should I replace a greenhouse cover?

Replace a cover when tears, loose seams, cloudy areas, or failed fasteners keep it from fitting and protecting plants as intended. There isn't one schedule for every cover; sun, wind, handling, and material all affect wear.

Inspect it regularly, especially before strong seasonal weather.