Home » Blog » Ground Screw Sizes: Selecting The Right Screws For Your ProjectGround Screw Sizes: Selecting The Right Screws For Your Project by Sam Jeans30 June 2025Share: The many different sizes of ground screwsWhen planning a foundation project, one of the first questions that inevitably arises is “what size ground screw do I need?”Get it wrong, and you’re either over-engineering (and overspending) or under-specifying, which risks structural problems down the line. Get it right, and you’ll enjoy strong, easy-to-install, and cost-effective foundations in almost any ground conditions!At the Ground Screw Centre (GSCUK), we’ve spent over 15 years developing our ground screw range, each option has been engineered for specific applications, load requirements, and installation methods. Whether you’re a DIY enthusiast tackling your first garden room or a contractor working on commercial developments, we’ll help you identify the right specification for your project. Let’s explore our ground screw sizes. Our Ground Screw SizesWe offer self-install options for DIY projects, professional installation sizes for larger builds, and specialist open-top designs for specific applications.The key difference isn’t just length – it’s diameter. Our 68mm ground screws are designed for hand installation. Our 76mm ground screws require professional equipment, while our 114mm open-top ground screws are designed to tackle the heaviest loads. Each diameter category offers different lengths to match varying ground conditions and structural requirements.Self-Install Ground Screws: Our 68mm Diameter RangeOur 68mm diameter ground screws represent the sweet spot for DIY installation. They’re substantial enough to handle high loads, yet manageable enough to install with hand tools. More importantly, they cover the vast majority of residential foundation requirements.68mm x 550mm Ground ScrewsLength: 550mmLoad capacity: 230kgInstall range: 100mm above ground levelWall thickness: 1.8mmInstallation: Manual or ratchet toolThe 550mm ground screws handle more applications than you might expect. They’re perfect for shed bases, basic decking, and garden storage where the ground is reasonably firm and the structure is relatively light. They’re our most affordable option, but that doesn’t mean they’re a compromise – they’re simply engineered for applications that don’t require heavier specifications.68mm x 850mm Ground ScrewsLength: 850mmLoad capacity: 640kgInstall range: 200mm above ground levelWall thickness: 2.5mmInstallation: Manual or ratchet toolWhen projects become more substantial – such as garden offices, larger decking, or sites with challenging ground conditions – the 850mm ground screws come into their own. They excel on sloped ground, where the extra length allows you to drive the screw deeper while maintaining adequate above-ground height for levelling.68mm x 1100mm Ground ScrewsLength: 1100mmLoad capacity: 970kgInstall range: 300mm above ground levelWall thickness: 1.8mmInstallation: Manual or ratchet toolThe 1100mm ground screws represent the maximum length we recommend for self-installation. They handle substantial garden rooms, challenging ground conditions, and applications that require serious foundation depth without the need for professional installation equipment.Professional Installation Ground Screws: Our 76mm Diameter RangeOur 76mm diameter ground screws require specialist electrical installation equipment, but they deliver significantly increased load-bearing capacity for more demanding applications. These sizes bridge the gap between DIY projects and heavy commercial requirements.76mm x 800mm Ground ScrewsLength: 800mmDiameter: 76mmInstallation: Professional electrical equipment requiredApplications: Commercial garden rooms, light industrialThe shortest option in our professional range offers enhanced load capacity while remaining manageable for smaller commercial projects that require more than DIY specifications can provide.76mm x 1250mm Ground ScrewsLength: 1250mmLoad capacity: 1880kgDiameter: 76mmWall thickness: 3.0mmInstallation: Professional electrical equipment requiredThese ground screws handle medium-scale commercial applications and larger residential projects where you need substantial load-bearing capacity and professional installation precision.76mm x 1600mm Ground ScrewsLength: 1600mmLoad capacity: 3160kgDiameter: 76mmWall thickness: 3.5mmInstallation: Professional electrical equipment requiredThe 1600mm option tackles more substantial structural requirements with increased wall thickness, ensuring long-term reliability under heavy loads for large commercial buildings and industrial applications.76mm x 2000mm Ground ScrewsLength: 2000mmLoad capacity: 4080kgDiameter: 76mmWall thickness: 3.5mmInstallation: Professional electrical equipment requiredThe longest 76mm option delivers serious commercial-grade foundation capability for major commercial developments, industrial facilities, and applications requiring maximum load-bearing within this diameter range.Commercial Grade Ground Screws: Our 114mm Open Top RangeOur 114mm open-top ground screws provide maximum load-bearing capacity for the most demanding commercial and industrial applications, featuring four external captive nuts for internal levelling.114mm x 1300mm Length: 1300mmLoad capacity: 3260kg compressionDiameter: 114mmWall thickness: 3mmDesign: Open top with four external captive nutsPerfect for ballstop netting, rugby posts, cricket nets, commercial signage, and sports facility infrastructure where you need substantial load capacity with specialised mounting options.114mm x 1600mm Open Top Ground ScrewsLength: 1600mmLoad capacity: 3670kg compressionDiameter: 114mmWall thickness: 3mmDesign: Open top with four external captive nutsThe largest in our standard range delivers maximum strength for major sports facilities, industrial infrastructure, and heavy-duty commercial structures requiring the ultimate load-bearing capacity.How to Choose the Right Ground Screw Size for Your ProjectGround screw sizing isn’t overly complicated, but getting it wrong can be costly. Too light and your foundations won’t cope with the loads; too heavy and you’re paying for engineering you don’t need. The key is understanding what factors matter the most for your specific project.Here’s what you need to consider.Working Out What Load Your Foundations Need to HandleWhat’s the total weight of your structure, including everything that will go inside it? Most people underestimate this, particularly for garden rooms where they plan to install heavy equipment or storage.Shed bases: typically lighter loads, perfect for our 550mm screwsGarden rooms and offices: heavier structures needing 850mm or 1100mm optionsCommercial buildings: require our professional 76mm or 114mm rangeA simple shed might generate less than 100 kg of load per foundation point, while a fully fitted garden office could easily exceed 800 kg or more. For niche projects, such as solar installations, you’ll also need to factor in wind forces. We offer professional load testing for heavier or more advanced projects. Reading Your Ground Conditions Your soil type determines how your ground screws will perform:Clay soils provide excellent holding power but may require professional assessmentSandy or loose soils typically need longer screws for adequate penetrationRocky ground offers great bearing strength but complicates installationSloped sites always benefit from longer screws for levelling flexibilityWaterlogged or very soft ground needs professional evaluationWe’ve created a guide on soil types and how they affect ground screws. If you’re unsure about your ground conditions, our technical team can provide guidance, so please contact us for support.Matching Installation Method to Your Skills and BudgetOur 68mm range is specifically designed for self-installation. However, there are situations where professional support can help achieve the best results for your project:DIY installation works best for straightforward projects on level groundProfessional installation handles challenging sites and heavy structuresConsider total project cost, not just foundation expensesFactor in your available time and physical demandsThink about warranty and liability implicationsThe bottom line is, DIY installation works brilliantly for straightforward projects on reasonably level ground, while professional installation makes sense for challenging sites or when you want the absolute peace of mind that comes with expert installation.Start Building on Foundations You Can TrustThe correct ground screw size primarily depends on the type of structure you’re building and its location.Most garden projects work well with our 68mm self-install range – the 550mm for lighter structures, 850mm for garden rooms, and 1100mm when you need extra depth or you’re dealing with slopes. Commercial applications typically require our 76mm professional range or the 114mm open top designs for heavy-duty work.The key factors are your structural loads, ground conditions, and whether you want to install yourself or use our professional service.Use our ground screw calculator for recommendations for your project, explore our complete range of ground screws and brackets, or contact our friendly team with any questions.
