You’ve had the heat pump installed. The cylinder’s in, the buffer tank’s plumbed, and the pipework is lagged. The engineer has packed up and gone, the system’s ticking away nicely, and now you’re left standing in a garage or utility cupboard that looks like a building site. Bare plasterboard, scuff marks everywhere, a few drill holes nobody bothered to fill. The heating works. The room? Not so much.
Most homeowners will just grab a tin of emulsion because that’s what you do with walls. But a plant room attached to a renewable heating system isn’t a spare bedroom. It runs warm, it runs damp, and whatever goes on those walls will have to put up with that for years. So here’s how the three main options stack up, what they’ll actually cost you over time, and why one of them tends to win out.
What Actually Happens Inside a Plant Room
A heat pump plant room behaves differently to almost any other space in the house. The cylinder kicks out heat constantly, and any unlagged pipework will sweat with condensation whenever there’s a temperature gap between the pipe surface and the room air.
Then there’s glycol. Most heat pump systems run a glycol-water mix through the primary circuit, and it’s pretty common to get small drips from compression fittings or pressure-relief valves during the first few months. Glycol is sticky, mildly corrosive, and it stains everything it touches.
Throw in poor ventilation on top of that (most converted cupboards and garages aren’t exactly well aired) and you’ve got a room that stays warmer and damper than anywhere else in the house. That’s the environment your wall finish has to survive in.
Emulsion Paint: Cheap but Short-Lived
A couple of coats of kitchen and bathroom emulsion will cost you next to nothing and take an afternoon. For the first six months, it’ll look fine. After that, it depends entirely on your plant room.
In a tight cupboard with a hot water cylinder running at 50°C, paint will start blistering within a season. Condensation forms behind the surface, the paint lifts, and mould creeps in underneath. You’ll repaint it, and the same thing will happen again. Glycol drips and general grime build up fast too, and emulsion doesn’t wipe down well at all. You can scrub it, but you’ll take the finish off in the process.
If you’re on a tight budget and the room is well ventilated, paint will do for now. Just know you’ll be doing it again before long.
Tiles: Durable but Overkill
Ceramic tiles can handle moisture and they clean up easily, but tiling a plant room means working around pipework, valves and manifolds the entire time. You’ll spend more time cutting tiles than actually laying them, and the cost adds up quickly. For a small space, expect to pay £400 or more with labour.
The bigger problem is access. If you ever need to get behind the wall to service pipework, you’re ripping tiles off and starting from scratch. Grout lines can also crack in rooms with regular temperature swings, which lets moisture get in behind the tiles and defeats the whole purpose.
PVC Panelling: The Middle Ground
This is where most people end up once they’ve ruled out paint and looked at the price of tiles. PVC wall panelling sits between the two on cost, and it’s far quicker to fit. Sheets can be cut with standard tools, fixed with adhesive or screws, and joined with matching trims. You can do a small plant room in a day.
The material handles moisture brilliantly. It won’t absorb water, it won’t blister, and it won’t need repainting every year. A hygienic cladding sheet rated for wet environments will easily stand up to glycol, cleaning chemicals and condensation without breaking down. That moisture and chemical resistance is exactly why PVC cladding is already standard in commercial kitchens and food processing units, and those same properties make it a solid choice for a domestic plant room too.
There’s a sustainability argument here as well. PVC cladding lasts significantly longer than paint, so you’ll use fewer materials over time. The sheets are recyclable at end of life, which makes them a better long-term option for anyone trying to cut down on household waste. And if you ever need to get at pipework behind the panels, you can just unscrew individual sections and take them off without wrecking the rest of the wall.
Don’t Leave the Room Half-Finished
It’s tempting to shut the door on the plant room and forget about it. But damp, unfinished walls will lead to mould, and mould in a warm, enclosed space spreads quickly. You’ll also spot a leak much sooner against a clean, light-coloured wall than against bare, stained plasterboard.
You’ve invested in a renewable heating system. The room around it deserves a finish that can actually keep up.
