So far I have a partial build of two layers of 3" latex. The bottom layer is 29ild dunlop (foam by mail) followed 3’’ 19ild dunlop (latex mattress factory).
This feels almost right, but I’d like to put a thin layer of memory foam on top. I tried our 2" 14ild memory foam from a smaller bed on top and that feels like too much memory foam (or too soft) and not supportive enough.
The main issue though is, the slats on our bed are too far apart with 3.5 inch gaps between. I was about to buy 2" of a dense foam both to add a bit more of a support layer and to protect the latex from squeezing through the gaps before I read about latex’s need for airflow. Is this a bad idea? FWIW, I’m not concerned with heat retention as much as longevity of the latex. If the foam base is a bad idea, my second thought was to put some thinner slats (maybe 1.5" wide in between the current slats). I’m welcome to any other suggestions as well. Thanks!
If it’s helpful, I’m 5’7 and about 135lbs and my partner is 5’9 and about the same weight.
You can put 1" slats with velcro stapled into the ends and on the rails. That will leave 1.25" on each side. Lowes, HD and even Amazon sell them. Just make sure you have the proper center support legs. Then you are golden!
Everyone has their own taste. With you weights and heights, my recommendation is to skip the viscoelastic memory foam and use something natural. Either talalay, cotton, wool, or 2" microcoils with a layer of latex on top.
I know memory foam is pressure relieving, etc etc, if you are going natural, my suggestion is to keep it that way. Your mattress will only be as good as its weakest layer. When it goes, the rest can soon follow. VE Memory Foam will become your weakest layer in your project. You have great materials to support the two of you, stay away from the quicksand in this build.
Just a quick note on the breathability of latex: latex foam is a naturally breathable, open celled product and a slatted foundation is not necessary for the mattress to sleep cool. A slatted foundation will enhance the breathability but certainly isn’t necessary because the mattress will breathe on all exposed sides.
If you end up putting a piece of plywood over the slats, you can order a coconut coir mattress pad to put on top of the plywood to enhance the breathability at the bottom of the mattress. Just some extra things to consider!