Practical guide to chases #plastering #tradesman #diy #homerenovation—from safe cutting and fixing to flawless patching, pricing, and client handover.
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Chasing walls looks simple until you hit a live cable, crack a wall, or the patch ghosts through the paint. This guide breaks down chases #plastering #tradesman #diy #homerenovation so you can cut clean channels, fix services properly, and plaster them out to an invisible finish. We’ll cover safe zones, structural limits, tools, step-by-step plastering, and the business side—quotes, client expectations, and handover. Whether you’re a tradesman coaching a mate or a DIYer upgrading your home, you’ll get practical tips you can use on the next room you tackle.
Quick Answer: Chases #plastering #tradesman #diy #homerenovation means cutting channels in walls for cables or pipes, securing services in safe zones, and backfilling with the right basecoat before a skim. Follow structural limits (typically one-third wall thickness for vertical, one-sixth for horizontal), prime, fill in layers, scrim edges, and finish flat.
Chases are recessed channels cut into masonry or plaster to run cables, conduits, or pipes. In chases #plastering #tradesman #diy #homerenovation work, the objective is a neat path that won’t weaken the wall, won’t crack later, and disappears after plaster. You’re balancing three things: compliance (safe zones and building guidance), durability (secure services and proper materials), and finish (flat, no ghosting).
Many contractors rush the cut and pay for it during finishing. The smarter play is to plan the route, size the chase correctly for the service—say 20 mm conduit or 15 mm copper—and decide the fill system before you start.
These are common routes used so future drilling is safer. If it’s not in a safe zone, expect callbacks.
Load-bearing or slender walls need extra caution. If in doubt, speak to the designer/engineer before cutting. Avoid back-to-back chases on opposite sides of the same wall and keep well clear of openings and lintels.
Plan the chase width and depth so you don’t overcut. For a 20 mm conduit, many contractors cut a 30–35 mm wide chase at roughly 25–30 mm depth in plaster plus a few millimetres into the block to allow a thin, strong backfill.
Tip: Good dust extraction captures most dust and keeps the site livable, especially on occupied renovations.
Common mistake: Overcutting horizontally. Keep horizontal runs as shallow and short as possible—less than one-sixth wall thickness is a sensible cap.
Pro tip: For multi-gang boxes, laser the height and use a straightedge to align. It saves you 20 minutes of fiddling later.
Choosing the right fill matters in chases #plastering #tradesman #diy #homerenovation. Here’s a quick comparison:
| Material | Where It Shines | Watch-Outs |
|---|---|---|
| Bonding plaster | Deep, internal chases; quick build in layers | Not for consistently wet areas |
| Hardwall | Robust base on medium-high suction backgrounds | Faster set; mix only what you’ll use |
| Sand/cement | Damp-prone areas or where impact resistance is key | Longer cure; needs good key |
| Multi-finish | Final skim over set basecoats | Working time typically 20–40 minutes |
Commonly, leaving basecoats 24 hours before skimming gives a steadier finish. On small chases, same-day skim is fine if the base is firm and not pulling excessively.
Many contractors price chases by metre plus per box/tee, then add for fill and skim. Keep it transparent: specify metreage, number of boxes, fill type (bonding, hardwall, sand/cement), and whether you’re skimming the whole wall or blending. Capture this on site with Donizo:
This flow commonly reduces back-and-forth and can save a few hours each week across multiple jobs. It also protects you if a client adds extras mid-job—just update and resend. [Learn more about invoicing].
In general, size chases to the minimum needed to house the service plus a 6–10 mm plaster cover. A typical 20 mm conduit often needs about 25–30 mm total depth through plaster and a little into the block. For structure, keep vertical chases under one-third wall thickness and horizontal under one-sixth.
You can, but be cautious. Keep vertical chases shallow and narrow, avoid long horizontal chases, and never chase both sides of the same wall in the same area. If you’re unsure of the wall type or the load path, get a designer or structural engineer to advise before cutting.
Use the right fill (bonding or hardwall in layers under 15 mm), scratch each layer, and bed a mesh scrim over the chase edges. Allow adequate set (commonly 24 hours for basecoats) before skimming. Control rapid drying and avoid bridging over moving pipes—sleeve or insulate them to limit movement transfer.
Yes—use safe zones: within 150 mm of corners and ceilings, and directly vertical or horizontal to switches and sockets. This applies widely in domestic work so future fixings avoid cables. Photograph your chases before covering so the route is documented for the client.
For most internal chases, bonding or hardwall in layered passes works well. In damp-prone areas, sand/cement is more durable. Always prime the background, build in layers under 15 mm, and finish with a multi-finish skim for a flat, paint-ready surface.
Done right, chases #plastering #tradesman #diy #homerenovation is straightforward: plan safe zones, respect structural limits (one-third vertical, one-sixth horizontal), build basecoats in layers under 15 mm, scrim edges, and skim flat within 20–40 minutes working time. Photograph routes, note metreage, and set expectations in writing. Capture details and generate a professional proposal with Donizo, get e-signed approval, and convert to an invoice in one click—so you spend more time on the wall and less in the inbox. Next step: walk your next job, record the chase plan, and send a same-day proposal.
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