Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Jul 28, 2009 5:18 PM
Joined: Nov 4, 2008
Points: 223
Well, i can't seem to get some of my questions answered, and i'm probably posting too much as a result!

Anyway, here are some of my questions:

1) will two twin foam mattresses (HR foam) pushed together, in the same mattress cover, reduce--considerably--motion transfer as opposed to a king-size foam mattress? What is the ideal setup for two people who want to sleep together but can't tolerate motion?

2) What should i get as my base--HR36-hq or LUX-hq? 6 inches or more? We're mostly side sleepers, boyfriend likes more firmness than i do, but doesn't really care.

3) Should i get super-soft foam or egg-crate as a topper? 2 inches or less?

4) Why can't i have different toppers for our (hypothetically separate twin) mattresses, if i can get different bases?

5) is 2.8 density HR foam the same in two different stores, or can they be very different?

5) Lastly, a salesman at Verlo told me that Latex can be bouncy, but doesn't have motion transfer. Are the two qualities (bounciness, no motion) compatible? I would think one would eliminate the other!

Thank you SO much for any advice/recommendations!!
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #5 Jul 29, 2009 2:52 PM
Location: Cypress, TX
Joined: Aug 28, 2008
Points: 41
1) That's a good question that I've never seen an answer to.  They also sell on eBay with different prices -- higher I think.

2) My original bed was, from bottom to top : 5" LUX-HQ, 2x 1" HD36-HQ, 2" Medium Latex, 1" Soft Latex, CuddleBed.  After about 5 months or so, we felt that some of the firmness had been lost, and this was evident by laying in the middle, which felt much firmer like we remembered the bed being when brand new.  I traced it down to the HD36 layers.  There were no body impressions, but rather a loss of ILD -- meaning it just was simply less supportive than when new, in the torso areas.  As others with more knowledge about foams than I have posted, PU foam cells will tear and break (or something to that effect) causing the resilience to degrade over time.  So, I relocated the HD36 to the very bottom, thereby rasing up the LUX -- you see, I still needed to maintain 10" total stack.  Eventually I may order a 2" piece of LUX to replace the HD36 entirely.

I suggest you start with 3" of softer material over top of the LUX.  It's your best guess as to what exactly to use.  Mix it up with different materials and/or ILDs, keep it all the same, whatever.  So long as its 'soft' enough.  The idea for the top layers is to provide comfort, to relieve pressure points, but not so much that you start have back/neck pains.

Eggcrate is nice, it is very cushy, and very popular as the top final layer.  It is more pillowy than a solid piece of the same material.  I'm not sure what LUX or HD36 egg crate would feel like... maybe a bit too firm for the very top layer.  I really don't know.  But I'm pretty sure that PU foam eggcrate is going to flatten out some within a year or so.  The softer it is, the more it will flatten I think.  But that stuff is fairly cheap and they sell it at every Walmart, Target, BBB, JCP, etc.

The three basic things that you are shooting for are:

1) Is the bed supportive enough?

2) Is the bed soft enough?

3) Will the bed last?

1&2 are a balancing act -- too much of one tends to cause the other to suffer.  3 is pretty much determined by the materials you choose.

Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #6 Jul 29, 2009 6:54 PM
Joined: Nov 4, 2008
Points: 223
thank you again--very helpful! I'll eventually post what we decide to buy, and how it works out.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #7 Jul 31, 2009 1:46 PM
Joined: Nov 4, 2008
Points: 223
I just spoke with a woman at FBM, who suggested (if i were to get the HD36-HQ as a base) that i get 8" of it, and add softening layers as necessary. She said the foam is denser when there's a thicker slab of it. This seems a little much, though...I guess with the LUX-HQ i don't need as thick a base; If i wanted a 'softer' base would going with the 8" of HD36-HQ work out--i.e. would it last longer, etc?
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #8 Jul 31, 2009 10:22 PM
Location: Mequon, WI
Joined: Aug 30, 2007
Points: 363
electracat wrote:
I just spoke with a woman at FBM, who suggested (if i were to get the HD36-HQ as a base) that i get 8" of it, and add softening layers as necessary. She said the foam is denser when there's a thicker slab of it.

Jeez.  This lady is a real trip.  I wonder where she came from.  She should NOT be trying to help people make informed decisions, IMHO.  It must be the same FBM salesperson who told someone in another thread that ILD can change with thickness.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #9 Aug 1, 2009 1:52 AM
Joined: Nov 4, 2008
Points: 223
Yes, i believe she said that "the density of foam changes with the thickness". Is that what you mean?

Thinking now about about a 4" LUX-HQ layer, with 2" HD36-HQ on top, and 2-3" of softening layers on top of that (egg crate, super-soft foam, something like that). How does that sound for a start? Too much base/mid layers?

thanks!
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #10 Aug 1, 2009 10:11 AM
Joined: Aug 16, 2008
Points: 16
Don't forget that standard twin mattresses are 5" shorter than king mattresses.  If you want to use two twins to make a king you need to use extra long twins.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #11 Aug 1, 2009 1:09 PM
Joined: Nov 4, 2008
Points: 223
i know--learned that the hard way!

I think we'll stick with one king...From what i can tell, the motion won't be considerably resolved with two twin mattresses (DIY foam layers) in a king frame.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #12 Aug 1, 2009 3:53 PM
Location: Mequon, WI
Joined: Aug 30, 2007
Points: 363
electracat wrote:
Yes, i believe she said that "the density of foam changes with the thickness". Is that what you mean?

Thinking now about about a 4" LUX-HQ layer, with 2" HD36-HQ on top, and 2-3" of softening layers on top of that (egg crate, super-soft foam, something like that). How does that sound for a start? Too much base/mid layers?

thanks!

Yes, that is what I meant.

I think your plan sounds like it could work.  I have never slept on the LUX-HQ or HD36-HQ before, so I can't comment on the feel of them.  However I can say that 6" of base and 2-3" of cush is a workable idea in general.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #13 Aug 2, 2009 2:18 PM
Joined: Nov 4, 2008
Points: 223
Would that set-up work if i'm a side sleeper? Just concerned about 'sinking' through the layers on top, onto the hard base layer.
Re: Will two foam twins have (considerably) less motion transfer than one king-size foam mattress?
Reply #14 Aug 2, 2009 8:41 PM
Location: Mequon, WI
Joined: Aug 30, 2007
Points: 363
I think so, but I can't say for sure.