Can you hang an oil painting in a bathroom?

The answer, and what it is not about

Of all the rooms in this pillar, this is the only one that gets a flat no, and it is the only one where the reason has nothing to do with who might see it.

A bathroom is, on the face of it, the obvious room for this work. It is private, it is the one place where a painting of a body is not a statement about anything, and it is usually the emptiest wall in the house. Every part of that is true and none of it survives contact with what the room does to an oil painting.

So: no. And unlike most advice of this kind, the failure is not dramatic. Nothing happens for two years. Then it has happened.

What humidity does to a stretched canvas

Canvas is hygroscopic, which means it takes moisture out of the air and gives it back. Wet air, and the fibres swell and the canvas tightens on the stretcher. Dry air, and it contracts. That much is normal; it happens on every wall in every house and a painting is built to live with it.

What a bathroom adds is amplitude and frequency. Relative humidity in an ordinary living room drifts slowly between roughly 40 and 60 percent across a year. A bathroom goes from that to near saturation in ten minutes, twice a day, every day, and back again.

The canvas moves. The layers on top of it — ground, acrylic underpainting, oil paint, and eventually varnish — do not all move at the same rate, and the oil film becomes less flexible as it ages. Repeated over thousands of cycles, the difference in movement shows up as a fine network of cracks in the paint surface. Conservators call it craquelure, museums hold galleries between about 45 and 55 percent relative humidity precisely to avoid it, and once it is there it is there.

Heat cycling, which people forget

The steam gets all the attention and the temperature does half the work.

A bathroom in use swings from around 18 degrees to around 26 in the space of a shower, and then falls back over an hour. Materials expand and contract with that, on top of the moisture movement, and in the same direction. Warm wet air also condenses on the coldest surface in the room — and if the painting is on an outside wall, the coldest surface in the room may well be the back of your canvas.

That last point is the one that catches people. Damp sitting on the reverse of a stretched canvas, out of sight, for years, is the mechanism behind most of the mould you will ever see on the back of a painting. It is the same reason the wall above a radiator is a problem from the other direction.

A print is not the way round it

The usual next thought is to put a print in there instead, and keep the canvas somewhere sensible. It is a reasonable idea and it does not work.

Paper is more responsive to humidity than canvas, not less. What it does is cockle: the sheet takes up moisture unevenly, ripples, and never lies flat again. Behind glass it is worse, because moisture that gets into the frame cannot get out, and paper in a sealed damp frame is where foxing comes from — the small brown spots you see on old prints.

If you want an image in a bathroom, the honest answer is that it should be something you would not mind replacing. That rules out a signed edition of any kind.

The cloakroom is a different room

Worth separating out, because people ask about "the bathroom" and mean four different rooms.

The downstairs cloakroom is a real answer and an underrated one. It is small, it is dry, everybody who visits goes in alone, and the wall is at arm's length — so a small canvas belongs there. The 50 × 30 cm and 70 × 50 cm sizes are made for a wall like that: Natalee (White Top) is 50 × 30 cm.

One thing to know before you do it. A cloakroom is the room a business visitor uses alone, with the door shut, with nothing else to look at — which makes it the single most concentrated version of every question in this pillar. Clients and colleagues in your house deals with that specifically.

What to put there instead

If a bathroom wall genuinely needs something on it, use something that has no conservation value to lose: a photograph you can reprint, a poster, an object, tile. The test is whether you would be annoyed if it were ruined in five years, because it will be.

And put the painting where it belongs. Where to hang a nude painting goes through the house room by room with a verdict on each, and the bedroom and the stairwell both do what people are hoping a bathroom will do, without the damage.

The paintings are here, with the size of each one, so you can pick a room for it before you pick a wall.

Questions people ask

Can you hang an oil painting in a bathroom?

No. Canvas swells and contracts with humidity while the paint film on top of it moves at a different rate, and a bathroom forces that cycle twice a day. Over years it produces cracking in the paint surface, which cannot be undone. The reason is conservation, not modesty.

Will a print survive a bathroom?

Less well than a canvas. Paper takes up moisture unevenly and cockles, and it never lies flat again. Behind glass it is worse, because trapped damp is what causes the brown spots you see on old prints. Anything in a bathroom should be something you can replace.

What if the bathroom has an extractor fan and a window?

It shortens the peak but does not remove the cycle, and the cycle is what does the damage. A large, well-ventilated bathroom is a slower version of the same problem rather than a different one.

What about a downstairs toilet with no shower?

That is a different room and the answer is yes. With no steam source it is simply a small dry room with a door. The wall is at arm's length, so keep the canvas small: 50 by 30 or 70 by 50 cm suits it.