Last Updated on September 22, 2026 by Umar Farooq
A washer drain pan is a shallow tray the machine stands in, and it does two jobs well: it catches drips from hose connections and it contains a slow leak long enough for you to notice. What it does not do — and this is the part nobody states plainly — is stop a flood, unless it has been plumbed to a drain. An unplumbed pan holds under ten gallons. A burst supply hose delivers about eleven gallons a minute.
That arithmetic is the whole decision, and no page selling pans puts the two numbers next to each other.
The two numbers, side by side
Take a standard pan. Oatey publishes the dimensions of theirs: high-impact polystyrene, “28 inches by 30 inches with a depth of 2-1/2 inches” (what is a washing machine drain pan). That is 2,100 cubic inches to the brim, and a US gallon is 231 cubic inches — so about nine gallons before a single thing is standing in it. The machine’s feet and base displace a good part of that, which is presumably why Oatey describes the capacity as “several gallons” rather than giving a figure.
Now the other side. State Farm, which pays for this kind of thing, puts the flow from a failed supply hose at an average of “650 gallons of water per hour”, out of a hose holding “about 70 pounds of pressure” — and the company paid “nearly $30 million” on those claims in a single year (a $30m load of laundry).
650 gallons an hour is a shade under eleven gallons a minute. Against a pan that holds nine gallons at the absolute brim.
So an unplumbed pan buys you somewhere under sixty seconds. If you are standing there, that is genuinely useful — it is the difference between turning the tap off and calling someone. If you are at work, it is nothing.
Plumbed or unplumbed is the only distinction that matters
Everything else about pans — plastic versus metal, brand, price — is detail next to this one question. Both of the guides above assume the pan is connected. Oatey: the pan “is typically connected to a drainage system, ensuring that collected water is safely directed away from the home.” This Old House describes the same thing, a drain hole piped “into your home’s plumbing or a nearby floor drain” (washing machine drain pan).
A plumbed pan is flood protection. Water arrives, water leaves, and the floor stays dry for as long as the supply runs.
An unplumbed pan is a drip tray. That is not worthless — most washing machine leaks are slow ones, from a weeping hose connection or a tired door seal, and a tray catches those for weeks while you work out where the water is coming from. Just do not buy one believing it covers the scenario that actually destroys floors.
If you cannot plumb it, the money is better spent on braided steel hoses and the habit of closing the taps when you go away. Hoses are what fail; see washing machine leaking water for tracing a leak you already have.
Plastic or metal
The choice is less interesting than it looks, and both competitor guides agree on the substance.
Plastic pans are light, cheap, rust-proof and easy to fit alone. This Old House’s caution is fair: they “may crack or degrade over time, especially under heavy washing machines.” Metal pans — aluminium or galvanised steel — take more weight and last longer, cost more, and can corrode where water sits.
For a domestic machine on a level floor, plastic is fine. Take metal if the machine is unusually heavy, if the pan will be walked on, or if the laundry is somewhere a cracked pan would go unnoticed for a year.
Where a washer drain pan is required, and where it just makes sense
Requirements are local, and this site will not pretend otherwise. Oatey refers to “areas where building codes mandate their installation”, which is accurate and vague. No model plumbing code we could open imposes a blanket requirement on washing machines — and the code text itself sits behind a publisher that blocks us, so no section number is quoted here. Ask your building department, or your managing agent if you rent or own a flat.
Where it makes sense regardless of any rule:
- Any machine above ground floor. The damage runs downwards into ceilings, and that is where the cost is.
- Over a finished floor — timber, laminate, anything that cups when wet.
- In a cupboard or closet, where a leak stays out of sight until it reaches a doorway.
- Where there is no floor drain, which is most homes.
- Flats and shared buildings, where the water reaches somebody else’s property.
A basement with a floor drain and a concrete slab is the one case where a pan adds very little.
The three things a pan can quietly make worse
Worth knowing before you fit one, because none of the sales pages mention any of them.
It hides a slow leak instead of revealing it. A drip that would have marked the floor now collects invisibly under the machine. Pull the machine out and look in the pan every few months, or the first sign will be the smell.
It holds moisture under the machine. A pan with standing water in a warm laundry cupboard is a mould site, which is the opposite of what people buy them for. A plumbed pan drains itself; an unplumbed one needs drying out by hand.
It can change how the machine sits. A washer must be level and firmly footed or it will walk, and a thin plastic pan flexing under one foot is exactly the kind of soft footing that starts that. Re-level the machine after the pan goes in, not before — how to level a washing machine — and if it starts moving on spin, the pan is a suspect: washing machine walks during spin.
FAQ
Is a washer drain pan required by code?
Not universally. Requirements are set locally, and they most often apply above ground floor or where there is no floor drain. Check with your building department rather than a blog — including this one.
Does a drain pan need to be connected to a drain?
To stop a flood, yes. Unconnected it holds under ten gallons, which a burst hose fills in under a minute. Unconnected it is still useful against drips and slow leaks.
What size drain pan do I need?
Measure the machine’s footprint and allow clearance around it. A common size is 28 by 30 inches; larger machines need larger pans, and the pan must not force the machine out of level.
Can you put a washing machine on a plastic pan?
Yes, and most people do. Check the pan is rated for the machine’s weight, sits flat, and does not flex under a foot — then re-level the machine once it is in place.
Will a drain pan stop water damage from a burst hose?
Only if it is plumbed to a drain. That is the single most important thing on this page, and it is the thing product pages leave out.
Do I still need a pan if I have a floor drain?
Usually not, if the floor is concrete and slopes to the drain. A pan still helps by keeping the drips contained rather than spreading them across the floor.
Where a pan helps, and where it does nothing
Fit one if the machine is upstairs, over a floor you care about, or in a flat — and plumb it if you possibly can. If you cannot plumb it, buy it for what it is: a tray that catches drips and gives you a few weeks’ warning, not something that will save your ceiling while you are out.
