Collection: Anchor kit

Why a Greenhouse Base and Anchor Kit Matter

A greenhouse is light for its size and presents a large flat surface to the wind. That combination is why frames lift, shift and twist in storms, and why anchoring is treated as part of the structure rather than as an accessory.

The damage is rarely dramatic at first. A frame that has moved a few millimetres out of square will bind at the door, drop glazing clips, and crack panes one at a time over the following months. By the time the cause is obvious, the repairs have cost more than the anchor kit would have.

Matching the Kit to Your Base

The right anchor depends on what the greenhouse stands on, and there is no universal fitting. Getting this wrong is the usual reason an anchor fails to hold.

• Soil and grass: spiral or auger anchors twist into the ground and grip below the surface. They suit most garden and allotment sites and can be removed if you move the frame.
• Gravel: augers pass through loose material and need to reach firm ground beneath, so length matters more than on soil.
• Paving and concrete: expansion bolts through the base frame into the slab. This is the most secure option and the least forgiving of a frame that is not square.
• Decking: fixings must reach the joists rather than the boards, which requires knowing where the joists run before you start.

Some models come with a manufacturer base frame that the anchors bolt through. If yours does, use it. It spreads the load along the whole footprint instead of concentrating it at four corners.

Fit It During Assembly

Anchoring is far easier while the frame is being built and still adjustable. Once the glazing is in, the frame is heavy, fragile and difficult to lift or square up, and reaching the base rail from inside means working around staging and beds.

It also means the frame is anchored square. A structure fixed down while true will stay true, which is the whole point.

Sites That Need More

Coastal plots, open fields, hilltops and anywhere funnelled between buildings all take more wind than an average garden. On those sites consider doubling the number of anchor points and checking them each spring rather than relying on the standard fitting count.

Lightweight structures need this most. A polytunnel or a portable frame has far less mass holding it down than a glazed house, and both rely almost entirely on ground fixings to stay put.

If a storm has already moved your frame, check the glazing clips and spare parts before assuming the structure is sound. Clips work loose long before glass breaks.