Fixings
Screws, bolts, anchors, brackets, and connectors for securing structural and non-structural elements in your extension build.
The fixings your builder uses by the hundred and you've never thought about. Until something falls off the wall.
Every connection in your extension relies on the right fixing in the right substrate. A wall plug in the wrong size hole holds nothing. A joist hanger with missing nails fails its building control inspection. A restraint strap that wasn't built in can't be properly retrofitted once the roof is on.
These guides explain what each fixing does, which type suits your substrate, how to check your builder is using the right ones, and what building control will be looking for when they inspect.
Where to start
Split fixings into two groups. Structural fixings hold the building together, and the engineer's calculations or building control can specify them: joist hangers, timber connectors and restraint straps, coach bolts, anchor bolts and chemical anchors. Everything else holds things to the building. The structural ones are worth checking yourself before they are covered up, because an inspector who finds a hanger short of nails will ask for it to be fixed before signing off.
The guides, grouped by job
Structural timber. Joist hangers, timber connectors (restraint straps, truss clips and framing anchors), angle brackets and coach bolts.
Fixing into masonry and concrete. Wall plugs for everyday fixings, frame fixings for window and door frames, anchor bolts for heavy loads, and chemical anchors where a mechanical anchor would crack the material or pull out.
Screws and nails. Wood screws, drywall screws, nails, and lost-head nails for skirting and architrave.
Where these fit in the build
Structural fixings go in during roof structure and steels and lintels, and building control looks at them at the structure inspection. Frame fixings go in with the windows and doors, and the rest are used from first fix to the last skirting board. If you are buying your own fixings, the wall plug sizes guide is the one to keep open, because a mismatched plug and screw is the most common reason a fixing pulls out.
Anchor Bolts: Which Type, Which Wall, and Why It Matters
The UK guide to expansion anchor bolts. Wedge, sleeve and shield anchors compared, substrate suitability explained, and the mistake that cracks your blockwork.
Angle Brackets: Which Duty, Which Fastener, and Why It Matters
The UK guide to angle brackets for timber framing. Light, medium and heavy-duty ratings explained, with prices from £1.00 – £1.17 upwards and the fastener mistake that weakens every joint.
Chemical Anchors (Resin Anchors): The Complete UK Guide to Resin Fixings
How to choose, install, and avoid failures with chemical anchors. Resin types compared, cure times by UK season, cost per fixing from £10.95 – £13.99, and the hole cleaning procedure that determines whether your steel beam stays put.
Coach Bolts: The Right Fixing for Structural Timber Connections
The complete UK guide to coach bolts (carriage bolts). Why mild steel beats high tensile, correct hole sizing, washer selection, and what to pay per bolt in zinc plated and stainless.
Drywall Screws: Sizes, Threads, and How Not to Wreck Plasterboard
The UK guide to drywall screws. Bugle head mechanics, coarse vs fine thread, NHBC spacing, why never to use an impact driver, and pricing from £7.50 per 1000.
Frame Fixings: The Right Way to Secure Window and Door Frames
How frame fixings work, which type to use, and why overtightening is the single biggest installation mistake. Nylon frame fixings vs concrete screws, spacing rules, length selection, and UK pricing.
Joist Hangers: The Fixings Building Control Will Actually Check
UK guide to joist hangers. Types, sizes, nailing requirements, and why building control will reject your floor if a single nail hole is empty. From £1.81 – £3.92 each.
Lost-Head Nails: The Right Fixing for Skirting, Architrave, and Internal Trim
UK guide to lost-head nails. BS 1202 sizes, 2.5x sizing rule, bright vs galvanised, hand-driving vs brad nailer, filler choices, and pricing from £9.00 – £9.49 per kg.
Nails: Types, Sizes, and When Each One Matters
The UK guide to construction nails. Ring shank vs round wire, joist hanger specifications, nail gun types, and current pricing from £6.29 a kilo upwards.
Timber Connectors: Restraint Straps, Truss Clips, and Framing Anchors
The UK guide to timber connectors for extensions. Restraint straps, truss clips, and framing anchors - what building control checks, what they cost from £0.47 to £6.00 – £7.49, and the installation details that matter.
Wall Plugs (Rawlplugs): The Size Matching Guide That Stops Fixings Failing
The UK guide to wall plug sizes, colours, and screw matching. Yellow is 5mm, red is 6mm, brown is 7mm. Get the combination wrong and your shelf hits the floor.
Wood Screws: Sizes, Types, and Which to Buy for Every Job
The UK guide to wood screws. Which gauge and length for which job, why your yellow screws will rust outside, and what to buy from £3.29 – £5.69 per box.