Hi Cynoclept,
I personally would avoid using a waterproof mattress encasement unless it was part of a more comprehensive program of controlling more severe dust mite allergies (see post #2 here) because it can reduce the ventilation of the mattress and can affect sleeping temperature for some people as well. Except for allergy issues … I would tend to use a mattress protector that can be more easily removed and cleaned instead (see post #89 here for more about the different types of mattress protectors).
[quote]However, I believe getting off the floor might be healthiest… I love the convenience of turning my mattress into a couch when I need to, so I’ve been looking at futons. My concern is that with a slatted frame I will lose the wonderful flat feeling I’ve become accustomed to, even with the rug on top of the slats. Considering this, I might want to add plywood or the like on top of the slats, with a rug to prevent another mildew issue.
What do you think will work best? If I stay on the floor with a mattress rug, will that be sufficient circulation? Is it healthier to be off the floor? Will my futon idea work? I realize I could get a full sized latex mattress to prevent feeling the slats, but I really dislike the feeling of thick bedding and love the firm wood feel.[/quote]
The height or type of your support system or whether it could turn into a couch would be a personal preference so this would be up to you and would be a preference choice rather than a “better worse” choice.
If you have a slatted support system that has only narrow gaps between the slats and there is little to no flex in the slats themselves then it’s unlikely that it would feel much different from having your mattress directly on the floor or on a solid surface. If you are either looking for a very low support system on the floor or something to add ventilation under a solid surface support system then I would use either the bed rug or one of the slat conversions here (which has no flex at all) or even one of the Ikea slatted bed bases here (which has some flex which may change how the mattress feels and performs). Any of these would provide good ventilation under the mattress although the slat conversion kit would be firmer than the other two.
If you do decide to choose a thinner futon as your sleeping system (either because it’s lower or because you want to use it on a futon frame to turn it into a couch) then post #2 here has some futon options that may be worth considering but this would also be a preference choice rather than a “better/worse” choice and any sleeping system that is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) would be fine … even if your sleeping system would be thinner or firmer (or lower) than most people would be comfortable with. If it works for you that’s all that really matters regardless of whether it would work well for anyone else.
Phoenix