Built Up Foundation: Used in lower
quality mattress sets,
this style is nothing more than a wood box covered in fabric to match the
mattress. To be honest with you, I've never seen one of these.
Grid Foundation: Found in most mass-produced, medium
to high-end mattress sets. I've owned these in the past.
Box Spring Foundation: Found in ultra-premium, mass
produced mattress sets. In my opinion, this is the most popular
foundation...it consists of a cloth-enclosed frame containing rows of coil
springs fastened together and to the frame are the most popular.
Split Foundation / Box Spring: A
split foundation/box spring is what it says, it is split in half length
wise.
The only time I've run into these is with
foundations for "King" beds.
Foundations, unlike mattresses, do not have
the ability to flex as they're taken around corners...so, making the
foundation into two pieces facilitates getting them into small spaces and
around corners.
Low-profile Foundations / Box Springs:
The new, extra thick, mattresses make it hard to get
in and out of bed, plus they're impossible when you want to sit on the
edge of the bed.
These, new, "Low-profile, foundations are about 1/2
the thickness of a regular foundation and still supply all the support
needed. I can't figure out why they don't make these the standard.
Not only do they make it easier to get in and out of
bed...they don't hid your beautiful headboard and footboard like the
thicker foundations do.