Preparing Your Greenhouse for Storms: A Comprehensive Guide

Lets face it – whether you believe in climate change or not, everyone can agree that we seem to be having more severe weather than we used to.  Less snow (for some of us), but more wind and rain!  In our increasingly turbulent climate, powerful and destructive storms are becoming an unavoidable reality (and they now have names!).   This brings challenges for greenhouse owners.  Here’s our guide to storm-proofing your greenhouse, ensuring it withstands the harshest conditions.

1. Repair and Reinforce:

Storm preparation begins with regular maintenance, applicable throughout the year.  Ensuring your greenhouse is maintained during the summer months will mean there’s less to do when the winter hits and repair and maintenance becomes difficult.  Damaged or loose glazing can quickly become a liability in high winds.  Top tips are:

• Replace Missing or Cracked Glazing: Broken or missing panes invite problems. Replace them promptly or, as a temporary measure, tape over cracks with strong adhesive tape.
• Secure Temporary Covers: If you lack time to replace a pane before a storm, cover gaps with durable plastic sheets or polycarbonate panels, ensuring they’re securely taped or tied.
• Check Glazing Clips and Seals: Missing clips or deteriorating seals weaken the structure. Replace these promptly, and keep spare clips on hand for emergencies.  You can also add a small amount of clear silicone to clips to help them stay in place and secure.
• Polycarbonate Greenhouses:  If your greenhouse has polycarbonate panels, we recommend running a line of clear silicone down the panels when installing.  Once dry, run another line down and use a dot on each clip to hold in place.  Remember that polycarbonate panels are very light, which in turn means that your greenhouse will be very light.  Weigh it down if you can.

2. Securing Your Greenhouse:

An anchored greenhouse is a resilient greenhouse. To minimise risks:

• Install a Solid Base:  We recommend paved or concrete bases as optimal (see our blog Let’s Talk Bases for our take on bases).
• Add Internal Bracing: Reinforce the frame with additional bracing kits or DIY supports, particularly in areas prone to high winds.  Some models of Elite Greenhouses offer additional bracing in the form of cantilevers as standard, which we recommend if your greenhouse is in an exposed area.  However, Elite sell these separately, and they can be added to any Elite greenhouse.
• Prevent Lifting: If your greenhouse sits on soil, ensure it is cemented into the soil at each corner.

3. Greenhouse Placement:

Strategic positioning is critical for storm resistance:

• Shelter from Winds: Place your greenhouse near hedges, fences, or walls that act as windbreaks. Living windbreaks, such as hedges or bamboo, dissipate wind force without redirecting it dangerously.
• Avoid Wind Tunnels: Be cautious when placing greenhouses between buildings, as these areas can amplify wind strength.

4. Pre-Storm Checklist:

Before a storm hits, follow these steps:

• Secure Doors: Close and lock the doors!  We’ve seen posts recently where people have been advised to leave doors open on the greenhouse to ‘let the wind run through’.  This is incorrect advice.  Ensure that all doors and windows are firmly closed.  Otherwise you’ll end up with an ‘umbrella effect’ inside the greenhouse and could blow glazing panels out.  If your door doesn’t have a lock, improvise.  Use a baton of wood and wedge it in the gap between the door and the side of the greenhouse – or use a heavy duty clip to block the door from opening.   Try not to use small unsecure objects like pots as these can come lose and create problems.
• Manual Vents:  Ensure the window stays are snugly secure onto the pins, or they can be wired shut using garden wire.
• Automatic Openers:  Auto openers can be disengaged to prevent accidental opening.  To do this you should remove the pin from the auto opener, lift the roof vent slightly, which will allow the cylinder to drop down.  Then unscrew the cylinder and put it somewhere cool and safe.  Additional pointer – don’t lose the pin!!  We recommend threading a piece of brightly coloured string around it in case you drop it, as they can be difficult to find once dropped.  Do this for all automatic openers.  Once the cylinders are removed, use a tie-wrap to wrap around the vents which will further ensure the roof vents stay closed.   We have seen advice recently where people have been told to just wrap string around the vents to stop them from opening – but this could cause damage unless you remove the cylinder first, if the temperatures rise and the vents try to open.  See our Blog post and video How to Disconnect Automatic Openers
• Remove Loose Objects: Pots, tools, and garden furniture can become projectiles. Store them securely or move them away from the greenhouse.
• Inspect Surroundings: Remove dead tree branches and repair any nearby structures that could collapse or damage your greenhouse.  Ensure any children’s toys like trampolines are anchored and secured too.

5. Long-Term:

If you’re considering a new greenhouse and planning to position it in an exposed area, invest in a model designed for storm resistance:

• Look for Strength Features: Choose greenhouses with robust frames, toughened glass, integral bases, and glazing capping/bar capping instead of spring clips.
• Insurance:  Ensure that your greenhouse is listed on your home insurance so that any damage can be repaired under your policy.
• Recommendations:  Our recommendation for exposed and/or coastal areas is the Elite Titan greenhouse due to its exceptional strength. Its robust design ensures it can withstand harsh weather conditions, making it an excellent investment for those seeking a durable and reliable greenhouse.
• Plan Placement Carefully: During installation, ensure the base is level and square to avoid structural gaps that could let wind in.  This is really important.  Again, see our blog Let’s Talk Bases!

6. Post-Storm Inspection:

After a storm passes, inspect your greenhouse thoroughly:

• Stay Safe: Never go inside your greenhouse while storms are taking place.  This is especially important for greenhouses with horticultural glass.
• Check for Damage: Look for displaced clips, cracked panes, or loosened seals, addressing issues immediately to prevent further damage.
• Reinforce Weak Points: If you notice areas that consistently sustain damage, consider relocating your greenhouse or adding additional protections like windbreaks.
• Insurance:  If your greenhouse does get damaged beyond repair by storms, get in touch with us and we can provide a free like-for-like quotation for replacements.

7. Installations:  

If you are installing your new greenhouse:

• Check the Weather:  Ensure that the weather forecast is staying fine for the following few days.  If any winds are forecast, reconsider beginning the installation and wait for better weather.
• Delays:  Always account and prepare for any delays to installations – if you think it might take 2 days, prepare for 3 just in case you hit any issues or it takes you a bit longer to build.
• Anchoring:  Always anchor the greenhouse down if you aren’t finished.  This can be done using ratchet straps or sand bags.
• Glass:  Never try to move glass panels in the wind.  It never ends well.