Outdoor fixings have a tougher job than indoor ones. Rain, damp, changing temperatures and exposure to the elements can all contribute to corrosion or loosening over time. Choosing the right screw or anchor starts with the material you’re fixing into, the conditions it will face and the load it needs to carry.
Start with the material you’re fixing into
Before choosing a fixing, identify the substrate: timber, brick, concrete or another material. A screw designed for timber won’t automatically suit masonry, and a masonry anchor needs the right base material and installation method to work properly.
- Timber: choose an exterior-rated screw with a length and head style suited to the job. For fences, sheds and outdoor fittings, make sure the screw is suitable for the timber and the conditions it will be exposed to. Browse our wood screws and check each product’s suitability for exterior use.
- Brick or concrete: use a fixing system designed for the specific masonry. Check whether it is suitable for solid or hollow material, and follow the maker’s guidance on hole size, depth and installation. For suitable concrete applications, see our concrete anchors.
- Unknown or fragile material: identify the substrate before drilling. If the fitting will carry a significant load, get advice on a suitable fixing rather than guessing.
Choose corrosion resistance for the conditions
For outdoor use, the finish or material matters. Coated or galvanised steel fixings can suit many general exterior applications, but the level of protection varies. Stainless steel is often chosen where greater corrosion resistance is needed. Grade 304 is commonly used for general outdoor environments, while grade 316 offers added resistance in more corrosive conditions, such as coastal or marine settings.
These are useful starting points, not a substitute for checking the product specification. Exposure, the materials being joined and the expected service life all matter. When working near the coast, around pools or in persistently damp locations, check the manufacturer’s recommendation for that exact use.
Match the fixing to the load and fitting
Think about what the fixing will support and how the load will act. A lightweight shed latch is different from a gate hinge that is repeatedly pulled and pushed. For masonry anchors, use a product rated for the base material and application. For timber, choose a suitable screw diameter and length, and avoid placing fixings too close to edges where the wood could split.
For safety-critical, overhead or heavily loaded fittings, don’t rely on a rule of thumb. Follow the fixing manufacturer’s load data and installation instructions, and get competent advice if the substrate or load is uncertain.
Don’t overlook compatibility
Different metals can react when they are in contact, especially in wet conditions. Where possible, use compatible fixings and fittings, and check guidance when combining stainless steel, galvanised steel, aluminium or treated timber. Some timber treatments can be more demanding on metal fixings, so confirm that the screw or connector is approved for the timber treatment in use.
Install carefully for a longer-lasting result
- Use the drill bit, pilot hole and installation method specified for the fixing.
- Keep drilled holes clean where the anchor instructions call for it.
- Don’t overtighten: it can damage the timber, fitting or anchor.
- Use the right washer or seal where the fitting design calls for one, especially where water could collect.
- Inspect outdoor fittings from time to time and replace fixings that show corrosion, movement or damage.
Quick checklist before you buy
Check the substrate, the load, the exposure to rain or salt, the fixing’s corrosion rating and the fitting material. Then follow the manufacturer’s installation instructions. A little care at the selection stage can help outdoor fittings stay secure and make the job last.
Always check the product’s stated application and installation guidance. If you’re unsure about the substrate, load or suitable fixing, ask a qualified installer or the fixing manufacturer for advice.