Latex beds, breathable foundations, and dust mite covers

Hi, I just got a latex mattress, and am trying to suss out what to do with it, lol. I always use a dust mite cover, and it’s water resistant, because I have pets. In shopping for a new dust mite cover for my new, larger, mattress, I’ve found that there are dust mite covers with a polyurethane lining, which makes them waterproof.

So, if I encased my latex mattress in that, would I still have to be concerned about moisture and breathability?

Is there some reason not to do that? Why don’t people just do that, instead of worrying about breathable foundations?

Thanks!

Hi Ducky1,

There is more information about the tradeoffs involved in different types of mattress protectors (and by extension mattress encasements which I generally don’t suggest unless there is a specific need that indicates it) in post #89 here.

The “membrane” type protectors or covers are generally less breathable than other types because being waterproof they only allow water vapor to pass through which can reduce ventilation compared to other types of cover. This reduction of ventilation in a mattress would be even more with an encasement than with just a protector that covered the surface of the mattress. Of course for many people the tradeoff between waterproof qualities (vs water resistant or just moisture absorbing) is worth it because you won’t have every benefit to the same degree in a single product.

Some of the cotton encasements which have smaller pore sizes such as these can also be an effective allergen barrier against dust mites and are more breathable but these are not waterproof.

Post #2 here may also be worth reading if dust mites are your biggest reason for choosing an encasement over a protector.

Everything is a matter of which of the tradeoffs involved in every choice are most important to you because you won’t find a single protector or encasement which has every property to the maximum degree where there are no tradeoffs involved.

Phoenix

PS: I deleted other other thread which was a duplicate

Thanks, Phoenix,

I do have dust mite allergies, and since instituting various measures to control the dm population in the house, I have had fewer symptoms. Even if I didn’t have a medical reason, though, the idea of the little buggers swarming everywhere and eventually dying and secreting in such numbers that they end up constituting a measurable percentage of a mattress or pillow would be enough to make me prefer encasements.

But, I’m still unclear on the “breathability” issue. I’m sure I’m just being dense and missing the point, here, so please explain it to me like I’m 5. If an encasement is less breathable than something else, it lets less moisture in, as well as less air in and out; so, would the end result be more damaging moisture in the mattress? Or would it average out to about the same?

Oh, wait, I think I just came up with a better way to ask my question: Since I’ve been happy with my dust mite encasement so far (a decade or so using a Pristine, which I think is all poly), on a regular mattress, would it have a different effect on latex or does latex have different breathability requirements than anything else?

Hi Ducky1,

There are several issues involved here that are separate (and would involve tradeoffs). One is protection from dust mites. Others include humidity and temperature control, how waterproof or water resistant a protector is, and how much it affects the feel of the mattress. All of these may affect your choices depending on which combination of benefits are most important to you.

For controlling dust mites … both the Pristine and the membrane type mattress encasements (and others as well) would work well. They have pore sizes that are small enough to help prevent the dust mites or skin flakes (their main food source) from entering the mattress and for the dust mites that are already in the mattress or that get in or multiply over time they will help prevent the allergens they produce from reaching you. So far so good.

Outside of protecting from allergens … some of the other comparisons are …

The membrane type is waterproof … the Pristine isn’t. This may play a role in your choice.

In terms of temperature control … all foam is an insulator even though latex is more breathable than polyfoam which in turn is more breathable than memory foam. If you put a less breathable layer over foam like a mattress encasement … it can make the foam even more insulating than it would otherwise be (like a house with foam insulation that is covered by a vapor barrier so there is no airflow and little heat exchange at all or sitting against leather which doesn’t breathe over the foam in your car seat). They don’t allow air to exchange or moisture to be removed in either direction from your skin or from inside the mattress. The less breathable a foam layer and the fabrics in your bedding are and the less they can wick moisture away from your skin … the more it will trap moisture on both sides of it. Wicking away water vapor and moisture and letting it evaporate into the atmosphere is how heat is removed from the area around your body and temperature is regulated in a mattress. This means that less breathable mattress encasements (with smaller pore sizes) will be warmer than more ventilating mattress encasements that allow more airflow or that do a better job of wicking moisture away … especially if they are over foam which is insulating to different degrees as well.

While I haven’t seen any airflow statistics for either … I would think that the Pristine would be more breathable than the membrane type encasements which only allow water vapor to go through them. You could ask them here which they believe allow more airflow or the degree of difference since they sell both types and would be familiar with how they compare but the Pristine would almost certainly be more breathable. Being polyester though … it also wouldn’t wick or absorb moisture nearly as well as more natural fibers and a similar cotton encasement with a small micron size would be better yet for temperature control because it is better at wicking moisture away into other layers and away from your body.

Both of these would sleep warmer than a mattress protector that had more fabric to wick away moisture and/or store it way from the body until it evaporated and also had larger pore sizes to allow more airflow as well.

I would also think that the Pristine or others like it would also have a little less effect on the feel of the mattress although both are quite thin and pliable (as long as they don’t fit too tightly and create a “drum” effect on the mattress.

So both of these or a cotton encasement would all be good choices for dust mite control but would have different effects on other factors that may be important to you.

The goal in these cases is to talk with the “experts” so that they can give you more information about the pros and cons of each from their own personal experience and you can choose the one that had the combination of benefits that were most important to you.

Phoenix

Ok, I think I get it. I will check with the folks you linked to, thanks. I still don’t get how moisture would be trapped in the mattress, if it can’t get in, in the first place. But, I do see that wicking might be eliminated.

Right now, I have a big, puffy, cloud-like regular mattress (the latex one is languishing behind the armchairs in the living room, waiting for me to decide on this stuff), with the Pristine encasement, and on top of that, a rather cheap but incredibly comfy cotton quilted mattress cover from, probably, Bed Bath and Beyond. It’s true, the Pristine without the quilted cover is a bit hard, so it does effect the feel. But, the amazingly comfy quilted cover handles that and probably the wicking issue, since I’ve never felt the bed is too hot or sweaty.

Can you take a guess at whether the cotton quilted cover might be sufficient to keep and wick moisture and heat away from the body, which is why I’ve never felt too hot, so far…and if it might be sufficient to do the same with the latex, or is that just a whole different ballpark?

Hi Ducky1,

Nothing is completely waterproof and even the air that gets into the mattress will have some moisture in it that will condense and can accumulate and with a less breathable cover would have a more difficult time getting out.

It may be more than you want to read but you read about some of the many factors that affect temperature control in post #2 here and in post #29 here.

The Pristine would be more breathable than a “membrane” type encasement so this may be part of the reason why and the cotton also wicks moisture very well (although it doesn’t store it nearly as well as wool). Each person can be very different as well though and what is warm for one may be perfectly fine for another. Natural fibers are generally better at regulating temperature than synthetics. Your own experience is certainly more important than any “theory” though because it “cuts to the chase” and says more about how all the layers and components of your sleeping system work together in combination than analyzing the properties of each layer separately which can be more useful if you need to make changes to cool your mattress down.

Since latex is the most breathable of the foams (probably more breathable and temperature regulating than the comfort layers in your big cloud like puffy mattress although I don’t know what they are), and you have already done well with the Pristeen and the cotton quilted cover over it, my guess is that you would very likely be fine in terms of temperature regulation with the same combination as long as you are OK with how they affect the “feel” of your new latex mattress.

Phoenix