How to Replace Panels on a Harbor Freight Greenhouse
Out with the old panels, in with the new!

Is your greenhouse feeling like a real pane? This season, let's turn over a new leaf and replace those worn-out panels! Our expert in-house repair technician, Mark, will guide you through this process step-by-step on a 6ft x 8ft greenhouse.

Why Should You Maintain Your Greenhouse?

Over time, your greenhouse panels may become discolored from wear and tear or UV radiation, or they could suffer damage from harsh weather conditions. Ignoring these issues can lead to a variety of problems:

  • Cloudy panels can block vital sunlight from reaching your plants, stunting their development and growth.
  • Cracks or holes in your panels can allow pests and disease to invade your greenhouse, putting your plants at risk.
  • Broken panels can compromise your greenhouse's ability to trap heat, resulting in temperature fluctuations that can make it difficult to maintain an optimal growing environment.

Even if you have a green thumb that would make St. Patrick's Day jealous, your greenhouse may be working against you. Don't let all your hard work go to waste! Let us show you how to give your greenhouse a new lease on life.

How to Replace Your Greenhouse’s Panels

Step One: Remove the Fixing Clips

Before starting, clear any items or plants from your greenhouse to create a workspace for yourself. It is also a good idea to wear protective gloves to keep your hands safe while working.

Next, focus on the steel fixing clips that are holding the panels in place. Use a pair of needle-nose pliers to loosen the clips and take them off. Be sure to set them aside so that you can reuse them later.

Expert technician removing the steel fixing clips from a roof panel of a greenhouse using pliers and wearing gloves

Step Two: Remove All the Panels

To remove a full panel, start by inserting a putty knife into the edges of the panel. Wiggle the knife in an up-and-down motion, being careful not to damage the greenhouse’s frame.

Expert technician using a putty knife to loosen the sides of a roof panel on a greenhouse by slotting the knife in between the panel and the roof frame and wiggling it

Once the panel has come loose, you can then remove it using your hands.

Expert technician wearing protective gloves and removing a roof panel from a greenhouse using their hands

To remove the smaller panels, start by examining the vent opener. Look for a nut on each side of its partition.

Expert technician locating the nuts found on the partition of a greenhouse vent and pointing the nuts out

Using a socket wrench, unthread these nuts and then pop the lower panel of the vent out.

Expert technician removing the lower panel of a greenhouse vent

Next, remove the partition completely so that you can take out the upper panel.

Expert technician removing the partition separating the panels of a greenhouse vent

Step Three: Remove the Leftover Caulk Around the Frame

Now that the panels have been removed, it's time to clean the greenhouse's frame so that you can work with a smooth and clean surface when reinstalling the panels. Start by peeling away the caulk with your fingers. If it's too tough to remove, use a caulk softener to make it easier to work with.

Expert technician peeling the leftover caulk off a greenhouse frame after removing all of its panels

Next, use a wire brush to clean any caulk residue from the frame.

Expert technician cleaning the frame of a greenhouse with a wire brush.

Once you've removed the caulk, finish off this step by blowing any dirt or debris from the frame's tracks with compressed air.

Expert technician blowing away dirt from a greenhouse's frame with compressed air

Step Four: Prepare the New Panels

Mark will be cutting new panels from four-by-eight double-wall polycarbonate sheets that are a quarter of an inch thick. These sheets are covered with a protective film on both sides, with one side being clear and the other blue. Since the blue side has UV protection, he will install that side outward.

Expert technician holding up a single sheet of double-wall-carbonate

To cut the sheets to size, use any standard woodworking tools like a circular saw or table saw with a fine-toothed blade. In the video, Mark uses a track saw to make precise cuts.

First, Mark measures and marks the sheet to the correct size, 23 5/8 inches.

Expert technician using a measuring tape and a marker to measure the size of a greenhouse panel and marking it on a sheet of double-wall polycarbonate

Then, he places the rail on top of the sheet, lining it up with the marks he made, and sets the saw to the proper depth.

Expert technician laying down the track for a track saw on top of a sheet of double-wall polycarbonate

He places the saw on the track and makes the cut. To cut the sheets to length, Mark cuts each wall piece at 47 3/4 inches and each roof piece at 44 inches long. The vent panel size is determined by the metal frame it fits inside, so take note of those measurements for your greenhouse.

Expert technician cutting a sheet of double-wall polycarbonate with a track saw

Step Five: Install the New Panels

To install the new panels, begin by removing the clear protective coating from the back side of the sheet. Leave the protective coating on the UV-protected side for now.

Expert technician removing the protective clear film on the double-wall polycarbonate

Next, align the sheet with the frame and slot it into place. Do this for all the large roof panels.

Expert technician installing a roof panel of a greenhouse by slotting it into its frame

Slide the small panel below the vent into place and reinstall the partition.

Expert technician installing the lower panel of a greenhouse vent

To install the vent panel, you'll need to remove the vent from the greenhouse first.

Expert technician removing the vent's frame from a greenhouse by pulling it out of the roof with their hands

Once the vent is removed, slide the panel into the vent’s frame and work it into place. Make sure it engages inside each of the grooves using a putty knife.

Expert technician fitting a new panel of double-wall polycarbonate into the vent frame of a greenhouse using a putty knife to work it in

Replace the vent and align it with the partition and the lower panel.

Expert technician placing the vent and partition pieces back into a greenhouse after removing them

Continue installing the new panels until you have replaced all of the old ones. Afterwards, remove the UV-protective film from all the panels.

Expert technician removing the blue UV protective film on a double-wall polycarbonate greenhouse wall panel

Reinstall the fixing clips.

Expert technician securing a greenhouse roof panel by installing steel fixing clips around its sides

Finally, seal the panels with caulk to prevent any drafts or water leakage.

Expert technician sealing the sides of new panels on a greenhouse by putting caulk along their edges

And Voila!

The result of this inexpensive renovation speaks for itself - you can now garden to your heart’s content!

Side-by-side comparison of two greenhouses, the greenhouse on the left has old and cloudy panels while the greenhouse on the right has clear and new panels

If you’re looking for more related reads, we have plenty of gardening blog articles for you to check out. Interested in more DIY videos? Good news! Our YouTube channel is chock full of helpful content.