A customer recently asked us for bed bug encasements for several mattresses, and not all of the same size. It is an increasingly common request from hotels, hostels and apartments, and it usually comes with two questions: what exactly does a cover like this do, and what do you need to give the supplier so that the one that arrives closes properly. This guide answers both. What it says about bed bugs comes from public health agencies and university entomology services, with the source named each time; what it says about measuring and making the cover is textile trade knowledge.
What a bed bug encasement is
It is a cover that wraps the mattress on all six sides and closes with a zip, made from a fabric that bed bugs cannot get through or bite through. It is not a protector or a mattress topper cover: those cover the top face and are held on with elastic or a stretch skirt, leaving the underside of the mattress open. A bed bug encasement shuts the mattress in.
That enclosure is its whole job. The US Environmental Protection Agency (EPA) puts it this way in its bed bug control guidance: with covers that seal the mattress and box spring, any bed bugs inside are trapped and die. The University of Kentucky's entomology department (Michael F. Potter, fact sheet ENTFACT-636, revised 2026) describes the same mechanism: once fitted and zipped shut, the bugs inside eventually die; and, as the Alaska Department of Environmental Conservation adds, any that arrive later have nowhere to hide. And in Spain, the bed bug prevention guide for overnight accommodation published by La Rioja's Directorate-General for Public Health (2023) recommends exactly this item: covers that fully enclose the mattress and have a secure closure giving complete isolation.
What it does, point by point
- It keeps them out. A mattress is full of hiding places for a bed bug: the piping, the seams, the quilting, the handles, the air vents. With the encasement on, all of that is out of reach. The EPA recommends covering mattress and base precisely to eliminate many of those hiding spots.
- It shuts in the ones already there. They cannot get out to feed, and in time they die. This is what the Australian code of practice for bed bug management (AEPMA, 5th edition, 2022, edited by entomologist Stephen Doggett) calls containment use, as opposed to preventive use on a clean mattress.
- It makes inspection easier. A smooth, light surface with few seams can be checked in a minute. The EPA says so explicitly: the light colour of the encasement makes bed bugs easier to see, and their spotting too. The La Rioja guide asks for daily checks of mattresses, bed linen and bed bases, and on a smooth encasement that check is quick.
If the base is upholstered, an ottoman base or a fabric-covered box spring, the same logic applies, and encasements for bases exist. The University of Kentucky adds a useful rule when you cannot cover everything: the base is harder to inspect than the mattress. For pillows, the pest control protocol of Zaragoza's Municipal Public Health Institute recommends the same as for the mattress: a special cover rather than throwing them away.
What it does not do: it does not get rid of an infestation
This is where precision matters, because it is where money is lost. An encasement does not treat an infestation. The AEPMA code says it plainly: mattress encasements "cannot by themselves stop bed bugs", and they should be part of a complete management programme. Bed bugs also hide in the headboard, the bed base, skirting boards, sockets and furniture, and the encasement reaches none of those places. Nor does it stop a bug hiding elsewhere in the room from climbing onto the bed and biting, as the University of Kentucky points out.
For accommodation, the official advice is clear. The same La Rioja guide recommends that, if bed bugs are suspected, you call in professional companies specialised in controlling them, registered in the official biocide services register of the autonomous community, and base the response on an integrated control plan. The UK's NHS sums it up for anyone: what you can do yourself is unlikely to get rid of them completely. The encasement is what you put on before, during and after professional treatment, not what replaces it.
A note on insecticide-"treated" covers: the Alaska Department of Environmental Conservation, in its guidance on bed bug encasements, does not recommend them, because they do not kill bed bugs effectively and they expose the sleeper to insecticide. The barrier is the fabric and the zip, not a chemical.
How long it stays on
A long time. The EPA's advice, in its official Spanish-language version, is direct: keep the encasements on for a year. It also asks you to buy a product that has been tested for bed bugs and is strong enough to last that year without tearing.
The reason is that bed bugs can go a long time without feeding, and how long depends on temperature. A Virginia Tech study published in Insects (Polanco, Miller and Brewster, 2011) measured mean survival without food of 41 to 143 days in adults and last-stage nymphs at 26 °C, less in insecticide-resistant strains. In cool rooms the period stretches: the University of Kentucky mentions a year or more below about 13 °C. So the prudent figure is a year at the very least, and in hotel practice the sensible approach is to treat the encasement as a permanent part of the mattress and leave it on.
Bed bug encasement, zipped cover and protector: not the same thing
The three get mixed up in catalogues, and each does a different job:
- Mattress protector. Covers the top face, fits with elastic or a stretch skirt and, if it has a membrane, stops liquids. It is the piece that goes to the laundry when there is a stain; we explain this in the guide to blood on a mattress. Against bed bugs it does nothing: the mattress is still open underneath and at the sides.
- Zipped mattress cover. Wraps the whole mattress and usually opens in an L, along one side and the head end, so it can be fitted without lifting the mattress. It is designed to protect against wear, dust and stains. Covering all six sides does not make it a bed bug encasement: unless the manufacturer says it has been tested as a bed bug barrier, do not treat it as one.
- Bed bug encasement. Wraps all six sides, but is also designed and tested so that bed bugs can neither get in nor get out: fine-tooth zip, a closed end and fabric that cannot be bitten through.
The difference lies in the details of the closure, and that is what to look at next.
What makes a good bed bug encasement
- A zip that runs almost all the way round. It usually runs along three sides, so the mattress can go in, with the end sealed. Through a gap you cannot see, a newly hatched nymph, around a millimetre long, gets in and out.
- Small, closely spaced teeth. The AEPMA code asks for zip teeth fine enough that young bed bugs cannot pass between them, and the Alaska Department of Environmental Conservation for very small, closely spaced teeth. Hold the closed zip up to the light: there should be no visible gap between one tooth and the next.
- A stop or lock at the end of the zip. It is the weak point of any cover. AEPMA mentions end stops that prevent bugs getting out or in, and the Texas A&M extension service advises that the zip pull should hook or be securable so the zip does not open by itself over time.
- Bite-proof fabric or membrane, and few seams. Few, tightly closed seams remove hiding places on the cover itself. AEPMA lists among the requirements a membrane bed bugs cannot get through.
- Tested against bed bugs. The EPA asks you to buy a product that has been tested for bed bugs. The Alaska guidance warns that most covers do not work against bed bugs, including some sold as bed bug proof; that is why it is worth asking for the test result, not just the words on the label.
- Tear-resistant. One tear defeats it. The EPA advises checking it regularly for holes, and Alaska every few months, padding sharp edges and bolts on the frame and base with felt, since those are what rip it.
Breathable and waterproof
For bed bugs, what counts is that the fabric cannot be bitten or crawled through; being waterproof does not stop them any better. But in accommodation the encasement will spend years under a guest, and there the fabric does matter. An encasement with a laminated polyurethane membrane is waterproof and lets vapour through, so the bed does not sweat or rustle. One made of non-breathable PVC or plastic is hot and noisy. If the encasement will stay on for a year or more, a breathable one makes a difference every night.
How it is washed, and what gets washed
An encasement meant to stay on is washed rarely, and always according to its label, especially if it has a membrane. The piece that goes into rotation is the one on top. The AEPMA code proposes exactly this: when the encasement is being used to contain bed bugs, it is covered with a protector or plain cover that can be washed and dried hot, and that is what goes to the laundry. It fits what you already do: the protector is changed with the sheets and the encasement stays put.
For bed linen and anything that is washed, the reference is a study published in the Journal of Economic Entomology (Naylor and Boase, 2010): a 60 °C wash killed every life stage of the bed bug, eggs included, as did a hot tumble dry for at least 30 minutes. The AEPMA code adds that at 40 °C not all eggs die, and the NHS gives the same guidance of 60 °C and a hot dryer for 30 minutes. The La Rioja guide includes in an establishment's cleaning plan washing bed linen at 60 °C or above and using the dryer wherever possible.
How to measure: three measurements, not two
This is the point that ruins the most orders. A fitted sheet allows some slack; a bed bug encasement does not. The supplier needs three measurements for each mattress: width, length and depth. "150 × 190" is not enough, because the depth determines the side panel that goes round the mattress, and that is where the zip sits.
If the encasement is too shallow, it will not close, or it closes with the zip under strain, which ends up opening or breaking right at the end, the very point that has to stay sealed. If it is too deep, there is spare fabric that wrinkles under the fitted sheet, catches, rubs and tears sooner. Either way the encasement stops being a barrier.
How to take them
- Measure the mattress on its base, with no sheets or protector, using a dressmaker's or builder's tape measure.
- Width: side to side, at the head and at the foot. A used mattress may have spread; if the two figures differ, take the larger.
- Length: from head to foot, down the middle.
- Depth: at the thickest point, usually the middle of one side. If the mattress has a sewn-on top layer, a pillow top, it counts in the measurement: it is part of the mattress.
- Write them down in centimetres and in this order: width × length × depth, for example 150 × 190 × 27.
Toppers add height
A loose topper adds anything from a few centimetres to considerably more, depending on the model, and forces a decision before you order. Either it goes inside the same encasement as the mattress, in which case you measure the depth with the topper in place on top, or it gets its own encasement, in which case you measure them separately. What does not work is measuring the mattress alone and then putting the topper inside: the encasement will not close.
If your mattresses are not all the same
That is normal in accommodation that has been renewed bit by bit, and it is exactly the case of the customer who wrote to us. Measure each model, not each nominal size: two 90 × 190 mattresses from different manufacturers can be 18 and 25 cm deep. Make a list by room with the three measurements and how many units there are of each, and send it like that. If the encasement is sold in depth ranges, choose the range that contains your measurement, never the one just below it. And remember that the fitted sheet goes on top of everything: the depth it takes has to cover the mattress once it is encased, as we explain in the guide to sheet sizes.
Fitting it
Two people, with the mattress stood on end or resting on the base, without dragging it against metal corners. The University of Kentucky warns specifically about tearing the encasement while fitting it. Close the zip right up to the stop, secure the pull if the cover allows it, and check the encasement at every deep clean of the room: seams, zip and corners. If there is a tear, the encasement is replaced; a home-made patch cannot be verified.
Lenora does not yet list bed bug encasements in the catalogue, but we can supply them on request. If you need them, send us the three measurements of each mattress, width, length and depth, and how many units there are of each, and we will reply with what we can supply.