Intro

On most jobs, the client wants a clean finish. Pipes and cables hidden. That’s where covering electrical conduits comes in. Done right, it looks sharp and stays safe. Done wrong, you get cracks, hotspots, and failed inspections. This guide explains what covering electrical conduits means, why it matters, and how to do it step by step. We’ll cover planning, compliance, materials, and clean finishes. You’ll see practical methods for walls, ceilings, and floors. Use this to avoid rework, cut callbacks, and hand over tidy work.

Quick Answer

Covering electrical conduits is the process of concealing surface or recessed conduit runs behind trunking, boxing, plasterboard, or plaster. Keep to safe zones, protect fire ratings, and maintain access to junctions. Use proper fixings, fillers, and primers. Allow 24–48 hours for drying and curing before final painting.

Table of Contents

• Key Takeaways
• Planning And Compliance For Covering Electrical Conduits
• Materials And Tools You’ll Need
• Methods For Covering Electrical Conduits
• Finishing For A Clean Look
• Common Mistakes To Avoid
• Pricing, Scope, And Client Sign-Off
• FAQ
• Conclusion

Key Takeaways

• Plan routes in safe zones and keep junctions accessible.
• Use the right method: trunking, boxing-in, chasing, or stud cover.
• Respect bend radius (≥4×D), clip spacing (300–500 mm), and fire stopping.
• Allow 24–48 hours for drying and curing before final paint.
• Get scope agreed in writing to prevent disputes and extras.

Planning And Compliance For Covering Electrical Conduits

Good planning saves time. It also keeps you within the rules.

• Stay in safe zones. In general, run vertically or horizontally to accessories and within 150 mm of ceiling lines and corners. No diagonal runs.
• Depth and protection. Commonly, if cables are less than 50 mm deep in walls, protect with RCD (30 mA) or mechanical protection. Metal conduit (20 mm) gives robust protection where needed.
• Chasing limits. A common rule of thumb is: vertical chases ≤ one-third wall thickness; horizontal chases ≤ one-sixth. Check with building control for structural walls.
• Bend radius. Keep bends smooth. Minimum is usually 4× the conduit diameter. For 20 mm conduit, aim for at least an 80 mm radius.
• Fire stopping. Where conduits pass through fire-rated elements, maintain the rating (30 or 60 minutes). Use intumescent mastic, collars, or fire foam as specified.
• Access is key. Don’t bury junction boxes, adaptable boxes, or pull points. Keep lids accessible behind a removable panel or within trunking.

If you’re covering electrical conduits in kitchens, plant rooms, or stair cores, check any extra fire and hygiene requirements. In flats, corridors may require 60-minute protection. On timber frames, watch notches and holes in studs—follow joist and stud drilling guidance.

Materials And Tools You’ll Need

Choose materials that suit the run and the finish you want.

• uPVC mini-trunking: 25×16 mm for single runs, 40×25 mm for larger bundles. Clip or adhesive fix at 300–400 mm centres.
• Steel or uPVC conduit: 20 mm common; 25 mm if you need more capacity.
• Boxing-in: 12.5 mm fire-rated plasterboard or 18 mm MDF with a removable front. Add timber grounds (38×38 mm) for fixing.
• Plaster and filler: bonding coat for deep patches, then a 2–3 mm skim. Use ready-mix filler for small chases.
• Fire-stopping: intumescent mastic, fire foam, or collars where required.
• Fixings: plugs and 4.5–5.0 mm screws for masonry; drywall screws for studs; suitable anchors for ceilings.
• Finishes: primer-sealer, flexible caulk for 2–3 mm joints, decorator’s caulk for corners.
• Tools: multi-tool, SDS drill, chasing tool with dust extraction, level, tape, pipe and cable detector, trowels, sanders, hole saws.

Methods For Covering Electrical Conduits

Pick the method that fits the site, the budget, and the fire strategy. Here are four common methods for covering electrical conduits.

1) Surface Trunking (Fastest, Least Disruption)

Use when you need speed and access.

1. Plan the route in safe zones. Mark centres and levels.
2. Cut trunking to length. Deburr edges.
3. Fix base at 300–400 mm centres. Keep it straight with a level.
4. Clip or tie conduits inside. Maintain bend radius (≥4×D).
5. Add accessories and covers. Leave a 1–2 mm expansion gap at ends.
6. Seal with a fine bead of caulk. Prime and paint to match walls.

Time: 1–2 hours for a 3 m run once the route is clear.

2) Boxing-In (Neater, Still Accessible)

Use where you need a cleaner look but still want access.

1. Fix timber grounds at 600 mm centres. Keep the boxing square.
2. Wrap with 12.5 mm plasterboard or 18 mm MDF. Consider fire-rated board if needed.
3. Screw-fix a removable face where access is needed. Use magnetic catches.
4. Tape joints. Apply a 2–3 mm skim. Sand smooth.
5. Prime and paint. Caulk 2–3 mm edges for a clean shadow line.

Time: 2–3 hours for a 3 m drop, plus 24 hours drying before paint.

3) Chase And Patch (Flush Finish In Masonry)

Use when the client wants conduits fully hidden.

1. Scan the wall for services. Mark the safe zone.
2. Chase to depth with a twin-blade chaser. Keep vertical or horizontal only.
3. Fix the conduit with saddles at 400 mm centres. Avoid crushing flexible types.
4. Backfill with bonding coat. Let it firm up (2–3 hours).
5. Skim 2–3 mm over the area. Feather out at least 150–200 mm wide.
6. Prime after 24 hours. Finish with two coats of paint.

Notes: Respect chase limits (≤ one-third vertical, ≤ one-sixth horizontal). Don’t bury junctions. Maintain 50 mm depth or ensure 30 mA RCD protection.

4) Stud Walls And Ceilings (Drylining Approach)

Great for refits or feature walls.

1. Notch or drill studs within rules. Keep holes central and 50–60% of stud width max (check system spec).
2. Use grommets or bushings on metal studs to protect conduits.
3. Route conduits vertically in the bay. Clip at 400–600 mm centres.
4. Board with 12.5 mm plasterboard. Use fire-rated board if the partition is rated.
5. Tape, fill, and skim 2–3 mm. Sand, prime, and paint.

Tip: Keep draw cords in longer runs. It saves you time on future pulls.

Finishing For A Clean Look

Clients judge the finish, not the effort. Keep it crisp.

• Feather wider than the chase. 150–200 mm either side avoids shadow lines.
• Use corner bead when boxing-in external corners. It protects against knocks.
• Prime patched areas with a sealer. It prevents flashing under paint.
• Caulk 2–3 mm gaps. Don’t overfill. Smooth with a wet finger.
• Match textures. On artex or textured walls, blend the pattern after the skim.
• Allow time: 24 hours for fillers; 48 hours for thick bonding coats. Paint after it’s fully dry.

Common Mistakes To Avoid

Avoid these to stop cracks, trips back, and failed checks.

• Burying junctions or adaptable boxes. Always keep access.
• Tight bends. Keep at least 4× the conduit diameter.
• Skipping RCD when depth is under 50 mm. Don’t risk it.
• Over-chasing structural walls. Respect the one-third and one-sixth guidance.
• Ignoring fire stopping. Seal every penetration in rated walls and floors (30 or 60 minutes as required).
• No allowance for movement. Leave 1–2 mm expansion for trunking. Outdoors, allow 5–10 mm with uPVC.
• Painting too soon. Give 24–48 hours to avoid hairline cracks.

Pricing, Scope, And Client Sign-Off

Covering electrical conduits often looks simple to clients, but hidden steps take time.

• Time allowances: 2–3 hours to chase and patch a 3 m run; 1–2 hours for trunking; plus 24–48 hours drying.
• Materials: trunking (25×16 mm or 40×25 mm), fixings every 300–400 mm, 2–3 mm skim, primer, caulk.
• Extras: fire-stopping, access panels, feature paint, and making-good over large areas.

Lock the scope down before you start. List the method (trunking, boxing, or chase), lengths in metres, number of accessories, fire-stopping locations, and finishing level. Many contractors find that recording site notes with photos prevents disputes. Tools like Donizo help you capture details via voice, generate a proposal, email it to the client, and get e-signature approval before plaster goes on. That one change can cut back-and-forth by half.

Internal link ideas to support this topic:

• Link “professional proposals” to your proposal guide.
• Link “change orders” to your variation management article.
• Link “invoice templates” to your invoicing resource.
• Link “project timelines” to your scheduling best practices.

FAQ

Can I plaster directly over conduit?

Yes, you can plaster over conduit as long as it’s in a safe zone, fixed properly, and junctions remain accessible. Use a bonding coat to cover the conduit first, then a 2–3 mm skim. Prime before painting. Don’t bury boxes or flexible connections.

How deep should conduits be if they’re chased in?

As a general guide, cables less than 50 mm deep should be RCD-protected (30 mA) or mechanically protected. Also respect structural chase limits: vertical chases ≤ one-third wall thickness, horizontal chases ≤ one-sixth. Always run vertical or horizontal in recognised safe zones.

Do I need fire-stopping when covering electrical conduits?

If conduits pass through a fire-rated wall, floor, or ceiling, yes. Maintain the element’s rating (commonly 30 or 60 minutes). Use intumescent mastic, collars, fire foam, or specified systems. Seal both sides and follow the manufacturer’s instructions.

What’s better: trunking or chasing?

Trunking is faster and keeps access flexible. It’s ideal for offices, plant rooms, and quick refits. Chasing gives a flush, high-end finish but takes longer and needs drying time. Pick based on budget, programme, and whether future access is important.

Can I cover flexible conduit the same way?

Usually yes, but don’t kink it. Maintain a bend radius of at least 4× the conduit diameter. Clip at 300–400 mm centres to prevent sagging. Flexible conduit is handy in ceilings and studs, but keep junctions and pull points accessible.

Conclusion

Covering electrical conduits is simple when you plan the route, respect safe zones, and finish well. Choose the right method—trunking, boxing, chasing, or stud work—then allow proper drying time and protect fire ratings. To avoid scope creep, document lengths, finish levels, and access points. If you want faster buy-in, platforms such as Donizo let you turn site notes into proposals, send them for e-signature, and invoice in one flow.

Next steps:

• Walk your next job and mark safe zones and access points.
• Pick a method and list materials with fixings at 300–400 mm centres.
• Get the scope agreed in writing before you lift a tool.