About Greenhouse Rainwater Downpipes & Harvesting
Installing a greenhouse rainwater downpipe system is the most effective way to harvest soft, chlorine-free water for your plants. A standard 8x6 greenhouse can collect over 20,000 litres of rainwater annually, providing a sustainable resource for acid-loving crops like tomatoes and blueberries. Our professional-grade kits feature UV-stabilised downpipe bungs and tubes specifically designed to fit the integral gutter systems of leading UK brands, ensuring a leak-free transition from gutter to water butt.
Why We Chose This Range
“The mistake many gardeners make is trying to use standard domestic house guttering on a greenhouse; the tolerances simply don't match. We curating our Rainwater Downpipe range based on 'Brand-Lock' precision. We chose these specific kits because they utilize high-grade EPDM rubber bungs that won't perish in the summer heat, ensuring the seal remains watertight for years. Harvesting rainwater isn't just about saving money; it’s about plant health—rainwater is naturally 'soft' and free from the salts found in UK tap water.”
— Matt, Founder of Greenhouse StoresComparison: Official Kits vs. Universal Alternatives
| Feature | Official Brand Kit | Universal Alternatives |
|---|---|---|
| Fitment | Millimetre Precision | Loose / Requires Sealant |
| Seal Type | EPDM Rubber Bung | Plastic Compression |
| Longevity | 10+ Years (UV Rated) | 2-3 Years (UV Degradation) |
| Maintenance | Minimal (Flush Only) | Frequent (Resealing Required) |
🔧 Matt's Installation Tip: The "Gutter Debris" Rule
Before you push your new downpipe bung into the gutter, check the 'fall' of your greenhouse. Most greenhouses are built perfectly level, which actually causes water to pool in the gutters. I always advise customers to slightly deepen the gutter at the downpipe end by clearing any grit or moss build-up, ensuring gravity does the work for you.
Crucially, if you are connecting to a water butt, ensure the butt is raised on a solid stand. This allows the downpipe to maintain a downward angle. If the tube has to go 'up' into the butt, the water will back up in your greenhouse gutters, leading to overflows and potential leaks.
Frequently Asked Questions
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Will these downpipes fit any greenhouse?
No, greenhouse gutters vary significantly between manufacturers. We stock brand-specific downpipe kits for Elite, Vitavia, and Halls. Our Elite Downpipe Kit is designed specifically for the unique 32mm outlet found on Elite models. Always check your gutter outlet diameter before purchasing.
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Do I need a kit for both sides of the greenhouse?
Most greenhouses have a gutter on both sides. To harvest maximum water, we recommend a downpipe kit for each side. You can then use a 'Y-connector' to feed both pipes into a single water butt, or use two separate butts for maximum storage capacity.
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Why should I use rainwater instead of tap water?
Rainwater is naturally slightly acidic and free from the chlorine and fluoride found in UK mains water. This makes it significantly better for acid-loving plants like tomatoes and prevents the build-up of white mineral salts on your pots and staging.
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