Key clamp handrails and guardrails

What key clamp is and where it makes sense

Key clamp, also sold as tube clamp, is a system of galvanised steel tube and malleable cast iron fittings: base flanges, elbows, tees, crosses and adjustable knuckles for rakes and odd angles. Each fitting slides over the tube and a grub screw is pulled up tight with a hex key. Nothing is welded, so there is no grinding, no paint touch-up and no hot work on site, and a run can be altered or extended later with the same key. It suits handrails, guard railing, safety barriers, racking frames and pedestrian guarding in commercial, industrial and domestic settings. It is not the right choice where you want a slim or decorative rail. For that you want a welded steel or stainless balustrade, which we also make.

Key clamp handrails for wheelchair access ramps and steps

Most of the key clamp we fit is handrail: along wheelchair access ramps, up a flight of external steps, or beside a sloping path. For a ramp to a shop, surgery or office, Approved Document M asks for a handrail on both sides, 900 to 1000 mm above the ramp surface, carried 300 mm past the top and bottom and closed back to the post so a sleeve cannot catch. It allows a round rail of 32 to 50 mm, and BS 8300 narrows that to 40 to 45 mm, so size 7 tube at 42.4 mm is the usual pick. On steps, Approved Document K wants the same height and a rail each side once the flight is 1000 mm or wider. Posts stand on base flanges or side-fix to a wall or the edge of the steps.

Roof edge protection and plant guard railing

Anyone who goes onto a flat roof to service air conditioning, clear gutters or check a rooflight is working at height, and the Work at Height Regulations expect whoever controls that work to guard the edge. A key clamp guard railing does that with no welding on the roof. The regulations set the top rail at a minimum of 950 mm, but we normally build to 1100 mm to match BS 6180 and Approved Document K for a roof edge, with a mid rail so no gap is over 470 mm and a toe board where tools could be kicked off. Posts fix to the parapet or upstand, or on a membrane roof a freestanding counterweighted frame keeps every fixing off the covering. We also guard rooflights, plant platforms and the drop beside a loading bay.

Barriers in yards, car parks and depots

Key clamp makes a quick barrier where people and vehicles mix: along a walkway through a yard, round the edge of a car park deck, or as a rail to stop trolleys rolling into a loading bay. BS 6180 sets the sideways load a barrier has to take, and it rises where a crowd could lean on it, so we set the post centres to suit, usually 1.5 to 2 metres and closer where the load is higher. Posts go on base flanges through-bolted to concrete, or are concreted into the ground where there is no slab. Mesh panels clamp into the frame where children will be about, so nothing wider than 100 mm can pass. For visibility we powder coat in safety yellow or black over the galvanising, and a gate can be built into any run.

Tube sizes, finishes and fixings

Key clamp tube comes in several sizes. The two we use most are size 7 at 42.4 mm, the handrail size, and size 8 at 48.3 mm, which we prefer for guard railing and barriers because it stiffens the run and takes a longer post spacing. The tube is galvanised and the fittings are hot-dip galvanised, so the bare system lasts outside without paint and weathers to a dull grey. Powder coating over the galvanising gives you a colour and suits a rail on show. Fixings depend on what the post is landing on: through-bolts or resin anchors into concrete, resin studs into brick, and a spreader plate or a fabricated bracket for a parapet or a steel beam. We check the base at the survey, because a flange bolted to weak screed is where these jobs go wrong.

Price and lead time

Key clamp is priced by the metre of rail plus the number of posts, corners and gates, so a straight run along a wall costs least and a stepped rail down a ramp with returns costs more. Ground fixing matters too: bolting to sound concrete is quick, while coring out and concreting posts takes longer. Galvanised tube and fittings are stock items, so a plain handrail is not held up waiting for material. A powder coated job goes to the plant first, which adds time, and we tell you how much when we quote. Send photos of the ramp, steps or roof with a rough length and you will have a written estimate within the working day. The site survey is free, the quotation holds unless you change the design, and the phones are answered 24 hours a day.

Straight answers on key clamp