Exposed heating pipes: painting them beats hiding them in trunking

Painting your heating pipes is cheaper than hiding them

A newly installed heating system leaves the pipes exposed, held in place with 15 and 18 mm double clips, and the question isn't aesthetic but economic: should you cover them with trunking or leave them bare? The answer that wins out in the discussion is the cheapest one and the most uncomfortable for anyone hoping for building work: leave them exposed and paint them. Every pipe that radiates is heat you've already paid for.

The starting problem is straight out of a catalogue. The trunking available on the market is the electrical type and requires a base plus a lid, a combination that doesn't fit an installation already up and running. There's no standard solution for the job, and anyone looking for one ends up in the plumbing aisle asking for parts that don't exist.

Can you cover heating pipes with trunking?

You can, but with caveats that advise against doing it carelessly. Some people have seen plastic trunking melted by pipes running through it without insulation, and others have seen oversized trunking holding a pipe plus a 9 mm insulation sleeve which, unable to be fixed to the wall because the installation is already in place, sit at all sorts of angles. The result isn't a clean solution: it's an expensive bodge.

The technical alternative does exist: flexible insulation sleeves, slit lengthwise and with an adhesive strip, for 15 and 18 mm pipe. The strips come in 2-metre lengths and it's best to order them 9 mm thick: they insulate less, but fit better in an awkward space. That said, they only make sense on sections running outdoors or on long runs where heat loss really matters.

Why you shouldn't insulate pipes indoors

The argument running through the whole discussion is simple: an exposed pipe indoors works as just another radiator. Insulating it means throwing away heat you've already bought. In areas where looks matter — behind a bed, at one end of the kitchen — the loss is accepted as a toll, but the technical consensus is clear: indoors, no insulation sleeves.

The middle option on the table is white skirting-style trunking, closed and painted, which conceals without insulating. It's the route that keeps the decorating-minded side of the household happy without giving up heat output entirely.

Paint: sealing primer, satin enamel and no gloss

If the decision is to leave the pipes exposed, the finish matters. The recommendation that comes up again and again is a proper sealing primer — essential — and satin enamel in the same colour as the wall. Emulsion paint works, but it gets dirty easily, chips with knocks and doesn't stand up well to mopping. Gloss, quite simply, is out.

The technical detail you shouldn't skip: if the primer is water-based, you need to watch out for copper verdigris showing through. With a solvent-based one, the risk disappears.

The building work ruled out and the debate left open

Chasing channels into the wall to embed the pipes is ruled out: it should have been planned before installation, and with the heating already running it would miccionan resizing all the pipes to fit inside the channels. Anyone who has already drilled into walls at home knows how heavy-duty that kind of tool is and how much it costs to sort out the parquet afterwards.

What's left is the purely aesthetic route: paint, disguise, and accept that exposed pipework is normal in almost every home. The question still without a definitive answer is how much heat is really lost on those sections you'd like to hide, and whether the decorative whim is worth the bill.