Technical guide · Pandaboard

WPC Handrail: Heights, Post Spacing and Base Plate Fixing

Direct answer

A WPC handrail is typically 60×80 to 70×90 mm on 90×90 mm posts spaced no more than 1200 mm apart. Set the rail at least 900 mm above the stair nosing, measured vertically, and at least 1050 mm on landings and open edges. Fix each post with a base plate of 6 mm or more and four M10 anchors into the structural slab, never into screed, insulation or tile. Connect the rail to the posts with matching brackets, use dedicated bends at corners, and stagger joints with a 2–3 mm gap for movement.

A WPC handrail consists of a handrail tube, posts, connectors and bases. It looks like timber and needs no painting. It is a safety component, not a decorative one: insufficient height, excessive post spacing or weak connections will all fail under load. This document sets out a safety-first method.

Safety bottom lineHandrail height (tread nose to top of rail) ≥900 on stairs, ≥1050 on landings and open edges; post spacing ≤1200; the rail must resist a 1 kN horizontal point load without permanent deformation. If any of these three cannot be met, do not hand over.

01Key specifications and suitability

Suitable

• Household stairs and landing guards

• Corridor handrails in public buildings

• Terraces, balconies and roof deck edges

• Both sides of ramps

• Commercial seating and walkway dividers

Not suitable

• Use as a structural member carrying building loads

• Sections buried in soil or permanently wet

• Escape stairs that require a certified fire rating

• Hot or heavily corrosive industrial platforms

• Horizontal-bar guards that children can climb

02Before Installation

2.1 Site check

• Confirm the substrate: concrete (cast-in items or expansion bolts), steel structure (weldable connection plate), floor tiles (base-plate type);

• Confirm the finished level of the stair treads and the starting position of the handrail;

• Confirm post positions at corners, landings and the junction of flights;

• Compare drawing heights with the actual site; where they differ, follow the site and record it.

2.2 Tools

Spirit level, tape measure, plumb bob, rotary hammer, wrench, hex key, cut-off saw (aluminum blade for WPC), angle grinder, sealant gun, timber props.

2.3 Parts list and reference quantities

Per 100 m of handrail, posts at 1200 mm; includes normal wastage.

2.4 Delivery and site conditioning

• Store profiles flat on bearers at ≤1.5 m centres, stacked no higher than 1.2 m so self-weight cannot bow them

• One batch and one series per project; flange height and hole positions differ between makers

• Spot-check 5 %: intact zinc or paint, undistorted section, length tolerance 5 mm

• Keep stainless fixings apart from carbon steel to avoid bimetallic corrosion

03Installation Steps (Base Plate Method)

Figure 1 — Handrail fixing section Base plate + 4 × M8 expansion bolts; post spacing ≤1200; splices with core insert and stainless screws.

1. Set out - Mark post positions on the treads or floor to the spacing; place a post at each corner, at the start and at the end.

2. Fix the base plate - Center the plate on the post position and anchor with 4 × M8 expansion bolts, embedment ≥60; the plate must sit tight on the floor with no gap — pack with thin steel shims if needed.

3. Install the post - Insert the post into the plate and fix with bolts or welding; plumb it in two directions to ≤2 mm/m with a plumb bob.

4. Reinforce the post - Where height is >1.1 m or the location is an open edge, add an internal core insert or brace the post back to the structure.

5. Install the handrail - Cut the rail to the section lengths and insert a core insert (length ≥100) at each splice, fixing both sides with 2 stainless self-drilling screws.

6. Corners - Use a factory bend or a 45° joint; seal the joint faces and keep the screws on the inner face.

7. Cap the ends - Fit end caps to every cut, with sealant inside the cap against water ingress.

8. Rigidity test - Push horizontally at the top of the rail by hand (about 1 kN): no movement, no permanent deformation.

9. Finishing - Clean the surfaces and check for exposed screws; replace exposed screws with countersunk heads and caps.

Splices must use a core insertButting two rail tubes face to face and relying on the end faces alone opens up or misaligns under load. Internal core insert plus screws on both sides is the standard detail: insert at least 100 long, embedded ≥50 into each tube.

04Other Fixing Methods

4.1 Cast-in (during concrete work)

• Before casting, set a steel plate (≥150×150×8) or cast-in bolts at the post positions set out on site;

• After the concrete reaches design strength, install the posts and connect by welding or bolting;

• Where a cast-in item is out of position by more than 20, use chemical anchors as a post-fixed connection.

4.2 Side-fixed (wall mounted)

• For wall-mounted and accessible handrails;

• Fix the connection plate to the wall with M8 expansion bolts at ≤1200 spacing;

• Keep a clear 40–50 between rail and wall so it can be gripped;

• On lightweight partitions, fix to the studs or cast-in items — never to the board face alone.

05Details and Junctions

• Stair start and finish: extend the rail horizontally ≥300 beyond the last riser and finish with a radiused or downturned end;

• Landing corners: use a factory bend with a radius matching the rail tube;

• Dog-leg stairs: provide a continuous rail or separate sections with a 10 gap between them;

• Glass / metal combinations: rail-to-post connectors must match the glass clamp system; never mix systems;

• External walls and terraces: all hardware in 316 stainless, all joints sealed with neutral silicone.

06Quality Acceptance

Table 6-1 — Acceptance requirements

07Common Problems

Table 7-1 — Typical defects

08Storage and Handling

Figure 2 — Stacking methods Store profiles flat and supported at several points; standing them upright or leaning them bows long lengths and leaves the rail out of line.

Table 8-1 — Storage conditions

Handling: carry long lengths with two people and no mid-span sag greater than 30 mm; never drag. Recommended stock life ≤12 months.

09Transport and Safety

• Load long lengths flat with supports ≤800 apart, corner protectors at both ends, lashed down;

• Avoid direct sun and rain;

• Wear goggles and a mask when cutting and drilling;

• Use a harness for work at height or near open edges; scaffolding or trestles must be inspected and approved;

• Carry out and record a rigidity test after installation; do not hand over untested work.

10Appendix: Checklist

10.1 Goods receiving

• □Profile specification, wall thickness, color match the order

• □No scratches, color difference or distortion

• □Connectors, core inserts and end caps complete

• □Hardware in 304 / 316 stainless

• □Same batch number

10.2 Before installation

• □Substrate type confirmed (concrete / steel / floor tile)

• □Post positions and heights set out and rechecked

• □Expansion bolt embedment conditions met

• □Corner bends and end caps available

• □Rigidity test procedure agreed

11Frequently asked questions

What height should the handrail be?

At least 900 mm above the stair nosing, measured vertically, and 1050 mm on landings, balconies and open edges. Houses, public buildings and schools may require more, and tall buildings often need a second rail; follow local codes.

Can I space the posts further apart?

Not advisable beyond 1200 mm. Wider spacing increases deflection under a horizontal push and opens the joints; hollow sections, public buildings and areas used by children should go to 900 mm.

Can I screw the posts straight into timber or tile?

No. Posts must be anchored into the concrete structure or a steel member with expansion or chemical anchors. Fixing into screed, insulation or tile lets the finish layer work loose under load.

Do the joints need a gap?

Yes. Leave 2–3 mm at each joint and a movement joint every 4–6 m on long runs, covered by a cap. WPC expands in summer, and tight joints push out at the ends or pull the bracket bolts loose.

WPC or aluminum — which is better?

WPC feels warm, does not conduct and needs no coating, but it is less stiff, so posts stay at 1200 mm or less. Aluminum holds tighter tolerances and is stiffer but hotter in sun. Outdoors and poolside, WPC with 316 fittings is usual.

Why does the handrail wobble?

Usually anchors that missed the structure, thin post walls, wide spacing or too few brackets. Add a backing plate or fix through the slab and fit brackets at every post; re-torquing will not cure a debonded substrate.

About Pandaboard

Guangzhou Panda Commercial Development Co., Ltd. · Pandaboard / PEIDA

We manufacture and export gypsum board, mineral fiber and fiberglass ceiling tiles, calcium silicate and magnesium oxide boards, fiber cement board, aluminum ceilings, WPC and SPC wall panels, exterior decking, fencing and handrails, together with the matching grid and framing systems. The methods on this page are compiled from product behaviour and standard trade practice; for any project, follow the approved drawings, local codes and the specification confirmed on your order.

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Guangzhou Panda Commercial Development Co., Ltd. · Pandaboard / PEIDA
This guide is technical information for specifiers and installers; it does not replace project drawings or local codes.