How to assemble a polycarbonate greenhouse

• Spanner and small socket set
• Cross-head screwdriver
• Spirit level
• Tape measure
• Step ladder
• Work gloves

Before you start, lay everything out on a soft surface (the flattened box works) and check it against the parts list in your manual.

• Base frame and ground anchors
• Aluminium wall, corner and roof profiles
• Ridge bar and gutters
• Polycarbonate wall and roof panels
• Sliding door, roof vent, clips and bolts

1. 1

   Step 1: Sort the aluminium profiles by the part numbers stamped on them and lay them out by wall; this saves more time than any other step.

2. 2

   Step 2: Build the base frame, place it on a level slab or timber base, and check it is square by measuring both diagonals until they match.

3. 3

   Step 3: Fix the base frame to the base or set the ground anchors into concrete as the manual describes, and let concrete set before loading the frame.

4. 4

   Step 4: Build each wall frame flat on the ground with bolts slid into the profile channels before you join the pieces, then stand the walls on the base and bolt the corners together.

5. 5

   Step 5: Fit the ridge bar, roof bars and gutters with a helper on the ladder, keeping bolts loose until the whole frame is up, then square it and tighten.

6. 6

   Step 6: Slide or clip in the polycarbonate panels with the UV-protected side facing out, as marked on the protective film, then peel off the film.

7. 7

   Step 7: Hang the sliding door on its runners and adjust it until it rolls freely, then fit the roof vent and its opener.

8. 8

   Step 8: Walk around the greenhouse and check every panel clip is seated; a loose panel is the first thing wind will take.

• Forgetting to slide bolts into a channel before closing it off, then having to strip the frame back down.
• Fitting panels with the UV side facing in, which makes them yellow and go brittle.
• Building on a base that is out of square, so the door jams and the last panels will not fit.