Ground screws, also known as screw piles or ground anchors, are a type of foundation system used for supporting various structures. Galvanised to provide long-lasting protection against corrosion, ground screws are driven into the ground to provide stability and support. Ground screws have helical threads that allow them to be screwed into the soil much like a wood screw into timber. Skin friction is created between the helical thread and the soil, allowing for large vertical loads to be applied to the ground screw and the weight transferred to the soil. 

Ground screws can be used in a variety of soil conditions, including clay-based and sandy soils. Their load-bearing capacity can be adjusted by altering the size and length of the screw, as well as the number of helical plates attached to the shaft. This flexibility makes them suitable for a wide range of applications, from small-scale residential projects like decking and sheds to large-scale structures, including Annexes, timber houses and shipping containers. 

One of the primary advantages of our ground screws is their ease of installation. They can be installed quickly using a range of tools, from simple handheld installation tools to electric ground screw installation machines. Construction time and labour costs tend to be much lower using ground screws compared to traditional methods using concrete. 

The maximum distance between ground screws is 1.5m when using a timber frame base. The timbers used in the frame should be no less than 4”x2”. Standard shed floor bearers are typically 40mmx40mm and cannot sit directly on top of ground screws. A timber frame must be built to sit the shed bearers on top. Extending the distance between ground screws beyond 1.5m will allow the timbers to flex, or, start encroaching on the load-bearing capacity limit of the foundations. 

The maximum distance between ground screws when using a SIPs (structural insulated panel) base is typically 1.2m, which is the standard width of a floor SIP. When using SIPs the joining timbers must sit on the ground screws, which will be every 1.2m with standard panels. If in doubt please send the SIP manufacturers drawings to info@sipsgroundscrews.co.uk and we can confirm the total number of ground screws required. 

The minimum distance between ground screws is 5x the diameter, including the helix. For our 68mm ground screws the minimum distance between them is 440mm. For our 76mm ground screws the minimum distance between them is 480mm. Reducing the distance between ground screws beyond these values can lead to interference of load transfer and reduced load-bearing capacity of the foundations. 

Our ground screws are hot dip galvanised with an average zinc plating thickness of 80uM. Hot dip galvanising protects ground screws through a metallurgical reaction where iron in the steel reacts with molten zinc to form a tightly bonded alloy layer. This layer, composed of zinc-iron alloys, creates a robust barrier against corrosion by acting as a sacrificial anode. The zinc corrodes preferentially, shielding the underlying steel from rust and environmental damage. Additionally, the coating's thickness and uniformity ensure consistent protection, enhancing the ground screws' durability and lifespan, making them ideal for long-term applications. Standard zinc coating depletion rates in the UK are around 1-2uM per year. The depletion rate varies with factors including moisture, humidity, soil pH and temperature. 

Our ground screws offer a versatile, eco-friendly solution for various construction projects. Unlike traditional concrete foundations, our ground screws are easy to install, cause minimal disruption to the environment, and provide a robust foundation for structures of all sizes.

Benefits of SIPs Ground Screws:

• Quick Installation: No need for excavation or concrete pouring, which saves time and labour costs. Tradespeople enjoy a mess-free day when installing our ground screws. We offer various accessories to make the installation process as smooth as possible. Predrill pilot holes using an SDS drill and use our extra long handlebar to gain leverage and torque. Manual installation can be sped up using two people to turn the handlebar. 
• Environmentally Friendly: Building concrete foundations result in a significantly higher carbon footprint than ground screw foundations. To understand more about the quantitive differences in CO2 released from both concrete and ground screw production, check out our blog post. Traditional concrete foundations disturb wildlife and plants in the area. At SIPs ground screws we frequently supply ground screws for projects where UK building regulations dictate that the surrounding environment must not be disturbed. Sites with old trees often require ground screw foundations to comply with building regs. 
• Fast Delivery: We hold stock of over 10,000 ground screws and deliver UK-wide in just 2 working days. 
• Versatility: We specialise in the supply of ground screws for garden rooms, sheds, and decking. These are just a few areas where ground screws are applicable and the superior choice for foundations. 
• Cost: At SIPs Ground Screws we offer price-competitive products. Trade discounts and price matching are available to ensure the very best price is always available to our customers.

We hold stock of over 10,000 ground screws of varying lengths to accommodate different structures and terrains. As a rule of thumb, no more than ⅓ of the length of the ground screw should be above ground. Extending the ground screws too far above ground can compromise the lateral stability of the foundations. 

The following recommendations assume flat solid ground. The installer is responsible for ensuring the correct provision and installation of ground screws. Please contact our team at info@sipsgroundscrews.co.uk if you require advice:

• For lightweight structures such as decking and sheds, 550mm ground screws are preferred. 
• For standard garden rooms, log cabins and outdoor timber buildings, 750mm ground screws are preferred. 
• Where sloping ground requires more of the ground screw to be above ground, 1000mm and 1400mm ground screws should be used. A hybrid of ground screw lengths is common, phasing in the longer screws when the threshold is met. 
• Where heavy loads are introduced such as hot tubs and gym equipment, the length of ground screw used can be increased or additional ground screws can be added to the foundations to accommodate the extra load.