I have been looking for a nice protector or pad for my all latex foam mattress for awhile now but the manufacturer always advises me specifically to NEVER use any type of waterproof / membrane type protector. They claim that the latex foam needs lots of airflow and that with a waterproof protector it is extremely likely that the mattress will mold or that the life of the latex will be significantly reduced. They only recommend thick wool puddle pads or similar type high airflow but water resistant pads. I know membrane protectors have been discussed to death here and I have done tons of searching on this forum but I was not able to find much discussion on this particular issue. I do not need a recommendation for a specific brand or anything - there is tons of info out there already about that (I suspect most are all using a similar polyurethane membrane anyways - probably made by Porelle).
I do know from experience that latex foam definitely does need plenty of airflow (not just for mold concerns) or the foam fairly quickly hardens up and starts to break down. Years ago I stuffed a nice latex foam pillow into a plastic garbage bag inside of a backpack and accidentally left it inside for a full month. When I removed the pillow from the garbage bag the foam was breaking down, had significantly hardened and become crusty, and went from a nice off-white color to a crusty brown / orange. Obviously I want to avoid this with my nice latex mattress as the pillow was completely ruined. Some questions below:
1. Has anyone used any of the membrane type protectors for extended periods of time (years) on a latex foam mattress and can comment on the condition of the foam? Did any of it mold or did any of it (especially the top layer of foam) start to turn a darker color or harden or flake?
2. Can someone with one of the “air permeable” polyurethane type membrane mattress protectors test the actual air permeability of the protector? The easiest way to do this is to simply put the fabric of the protector up to your mouth and attempt to breathe through it.
Most waterproof but air permeable PU membranes will pass a small amount of air but still be quite difficult to breathe through. I am wondering just how much airflow is able to flow through these as I have a lot of direct experience with PU membranes and they vary significantly in CFM.
3. Are there any PU membrane protectors (air permeable type) that ONLY go over the top of the mattress?
I know I could cut off the sides of any of them but I might feel safer with one that is either only a top sheet or has stretchy sides that do not have a membrane (just cotton or polyester or whatever the sides).
4. Has anyone experimented with putting the protector BELOW the outer casing of their mattress but OVER the latex foam layers?
I have my three dunlop latex foam layers inside a very thin cotton zippered case to hold it physically all together and then outside of that is a fully enclosed and zippered thick cotton cover. I am thinking that putting the waterproof layer below the outer cover would be a lot more comfortable and less hot since there will be thick layer of cotton pillowtop between myself and the membrane.
5. Has anyone ever seen a water resistant but not waterproof mattress pad that still allows high airflow but is not a thick wool type cover?
I know for example in the outdoors industry there are many types of thin woven nylons that are coated in a light layer of silicone that are not at all waterproof but still quite water resistant. And these materials usually pass a hell of a lot more airflow than anything waterproof which makes me think they might be a good candidate to put below the pillow top and above the latex.
In summary:
I am specifically only concerned with issues related to water resistance and making sure the foam in t his mattress has as much longevity as possible - body oils, light stains, mites, etc I am not concerned with and already have a nice working solution. I am hoping to get 30 years out of this mattress if possible.