Built a DIY latex last year in queen. Bought Quantum Edge Elite Bolsa coils (6") and a 3" Soft Natural Talalay Latex Topper. I also have this rather thick Bamboo cover/encasement from Arizona Premium Mattress.
When my coils are sitting out on the frame they measure around 79" long, so not quite 80" of a queen but close. But once I put them in the cover, add the topper, and close it, they seem to compress to around 75" or even less. This causes severe overhand of the topper. When I put the coils in the cover, they stay at 79" so over a day or two they condense down to 74-75", which is a huge problem. I am tall, so I don’t want to just cut my topper to match. The place I bought the coils told me to just glue the topper and coils together.
Any suggestions? Do I have a lemon for the coils or is something else going on here?
Hi BobLoblaw.
Welcome to our Mattress Forum. 
Thanks for asking your question here!
I know this is a super obvious question - have you checked the measurement on the encasement?
Before gluing, I’d suggest some other type of stabilization layer like coconut coir to see if that prevents the shifting.
We have quite a few DIYers here who may have experienced this and can weigh in. You may also want to ask Ken Hightower at @Arizona_Premium - he might have some troubleshooting ideas for you!
NikkiTMU
Did you buy the coils and topper from us also or only the zippered cover?
Ken
Hi Nikki, the encasement does appear to be 79-80".
Hi Ken,
I purchased the coils and zippered cover from you.
You may have noticed we no longer carry that coil because of this very issue. What we can do to fix the issue is send a piece of foam to fill in the void which you can place either at the head or foot of the coil. Please contact us directly at 888-773-7326
Thanks Ken. I’ll give the number a call tomorrow