
Kingsdown Twin Xl High Profile Foundation
Will It Fit?
SKU: 50883478
You'll Love Kingsdown
Kingsdown foundations are meticulously hand assembled using sustainably sourced Canadian Spruce, which is exceptionally durable. Each piece of lumber is not only heat-treated, but kiln-dried, which improves the performance of the wood over time. Each wooden slat is placed more closely together and cut a full inch wider than most manufacturers to provide a sturdier base.
Collection
Box Spring
Warranty
10 year limited warranty -
Code J -
View WarrantyColor
Black
Foundation height
9 inches
Pattern
Solid
Upholstery material
Fabric
Q&A answers generated with AI assistance.
How does the slat construction provide better support for a mattress?
To provide a sturdier base than standard models, the wooden slats in this foundation are cut a full inch wider and placed more closely together. This increased surface area offers superior reinforcement for your mattress, helping to prevent the sagging and dipping that can occur with less robust support systems, thereby extending the life of your mattress.
Why is kiln-dried Canadian Spruce used in this foundation’s frame?
This foundation is crafted from sustainably sourced Canadian Spruce that has been both heat-treated and kiln-dried. The kiln-drying process is a critical quality step that removes deep-seated moisture from the wood, significantly reducing the risk of warping, shrinking, or cracking over time. This expertise in material preparation ensures the frame remains structurally sound and silent throughout its lifespan.
Why is a solid foundation often preferred over a traditional box spring?
Unlike a traditional box spring that uses flexible wire coils, this solid wood foundation provides a completely flat, non-yielding surface. This rigid support is essential for modern memory foam and hybrid mattresses, as it ensures they stay perfectly level to provide correct spinal alignment and prevents the internal mattress materials from shifting or warping.
Does this foundation require home assembly?
No, this foundation is meticulously hand-assembled by craftsmen before it reaches your home. It arrives fully built and ready for immediate use, allowing you to complete your bedroom setup without the need for tools or the hassle of complex instructions.
What is the benefit of a "high profile" 9-inch foundation?
A 9-inch high-profile foundation provides a traditional bed height, making it easier to get in and out of bed compared to lower-profile options. This height is ideal for standard bed frames and is a popular choice for larger master bedrooms where a taller bed profile creates a more substantial, elevated aesthetic.
Can two of these foundations be used together for a split king bed?
Yes, two Twin XL foundations are the standard requirement for a King or Split King mattress setup. At 80 inches long, they provide the necessary extra length for "XL" mattresses. Placing two side-by-side creates a stable, 78-inch wide base that is much easier to navigate through narrow stairwells or apartment doorways than a single-piece king foundation.
39.00"w x 80.00"d x 9.00"h

4.7 out of 5 stars
Complements the mattress completely
This review was collected as part of a promotion
The foundation works like it’s supposed to..quietly and out of sight.
Review provided by Stearns & Foster
Decent but does have a squeak
This review was collected as part of a promotion
Foundation seems to be decent quality, but does have a squeak when initially getting in bed on the edges. My old Tempur-Pedic foundation did not do that.
Review provided by Stearns & Foster
Perfect foundt
This review was collected as part of a promotion
This unsung hero is the perfect match for our brand new Stearns and foster mattress! It’s just the right height, well-made, and quality construction.
Review provided by Stearns & Foster
Must have
Must have if you buy the best mattress Sterns Foster
Great Foundation
This review was collected as part of a promotion
This 9” Stearns & Foster Flat Foundation is the perfect height to give our new mattress a lift. It fits perfectly in our Queen bed frame. It is well made. Highly recommend this item.
Review provided by Stearns & Foster















