I am in the market for a new bed and have been soaking in all the outstanding information available on this website. My wife and I are replacing a 15 year old Serta Coil Spring that is causing us both aches and soreness in the morning. I was set to buy a Novafoam 14" Gel Memory Foam mattress at Costco until I found this website. Though I am sure that mattress would have been fine for a couple of years, after much research the Ultimate Dreams Latex (really Latex Over Foam?) seems to be the best quality/value for my budget, most likely in a 5 or 6 Firmness level.
My question is regarding an appropriate foundation. I have a Cherry Four Poster Bed that the existing Serta Box Spring fits into nicely. I checked out the box spring and it seems to be in great shape, and is made of interleaved wire grid pattern of 3 3/8 squares, covered by a sturdy cloth fabric. The grid does not appear to be worn out as I have pushed down on it in various spots. Would this be OK to use if we like the way the new bed feels on this foundation? It may make it slightly less firm with a bit more give. I don’t currently have the budget for an expensive foundation and would need to make it fit in the bed frame.
I plan on buying the same mattress (12" version), and have Beauty-rest box springs that look almost identical to that, 18 years old, but looks flat and very firm. Sits on slats on the floor (no legs). Also want to know if that is adequate.
Does the density of 1.5# in the base layer have any influence on the foundation? I may buy the Bamboo Bliss direct from Brooklyn Bedding with the 2.17# base foam if it will work better on this foundation. I’d rather save the $150 on the Ultimate Dreams though.
If yours is a box spring with flex in it (as opposed to a foundation) and is also 18 years old then I would probably replace it. You can see the guidelines here where Brooklyn Bedding specifically cautions against the use of box springs with a latex or memory foam mattress.
If yours is a foundation (not a boxspring) that doesn’t have any flex in it (or only a very slight amount of give if you press down with your knees with heavy pressure) and has no soft or weaker areas then it may be OK although at 18 years old I would still tend to replace it.
From the BB website: “Placing the mattress on plywood, such as a platform bed, is acceptable.”, so if the springs have too much flex, just put a thin piece of plywood on top. I can walk on top of my Simmons foundation and only sinks maybe an inch (with 190# on it), with plywood I doubt it would sink 1/8".
I think that plywood can be an OK “stopgap” solution for the short term but it also has some disadvantages and I don’t think it’s the best long term solution for supporting a mattress.
If you put plywood on a flexing boxspring it won’t be as stable and will have more sway (and possibly noise) than putting a mattress on a more rigid foundation.
It will also restrict airflow under the mattress which in combination with other risk factors can increase the likelihood of mold and mildew and even the dust mite population (they like warm, humid environments with little airflow) . There is more about this in post #10 here.
If you do choose to go in this direction I would make sure that the plywood was finished on at least one side to reduce the risk of splinters and snagging and damaging the mattress cover (and possibly reduce moisture as well).
Plywood also uses glue with solvents so this may be an issue for some people.
Finally, while I personally wouldn’t go in this direction unless there were no other good options or I was only thinking about short term use, for those who do I would use 3/4" plywood to prevent the risk of sagging under the heavier parts of the body over time.