Kingsdown Twin 3" Foundation - Image 1
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Kingsdown Twin 3" Foundation

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SKU: 51205550

KINGSDOWN Quality Craftsman Since 1904. A blue and white mattress on a bed frame in a modern, well-lit bedroom.
Style + SUBSTANCE. Since 1904, Kingsdown has handcrafted mattresses in the US with superior materials and quality.
Handcrafted Excellence
Handcrafted Excellence

Handcrafted in the United States, our master artisans are committed to better sleep through exceptional craftsmanship.

Finest Materials
Finest Materials

Every square inch of a Kingsdown mattress is handcrafted with superior materials, not just the parts you can see and touch.

Tested and Certified
Tested and Certified

Every single mattress is tested and certified before it leaves our hands to ensure consistent quality and accurate support.

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Kingsdown

For over a century, the Kingsdown name has been synonymous with unprecedented quality. Every detail is considered, and we ensure superior material selection and perfection, right down to the last stitch of our renowned tailoring. Since 1904, we’ve never compromised on comfort, and neither should you.

You'll Love Kingsdown

Sleep Cooler
Sleep Cooler

Kingsdown mattresses are designed to help regulate temperature for cooler, more comfortable sleep.

Motion Isolation
Motion Isolation

Individually wrapped coils decrease motion transfer, and select models feature an added buffer that runs the length of the mattress to mitigate partner disturbance.

Highly Rated
Highly Rated

Kingsdown mattresses are highly rated with over 20,000 reviews, averaging 4.7 stars and a 96% referral rate.

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 Warranty

Color

Black

Pattern

Solid

Profile height

3 inch

Type

Bed frame

Upholstery material

Upholstered

Q&A answers generated with AI assistance.

Why is kiln-dried Canadian Spruce used for this foundation?

We utilize sustainably sourced Canadian Spruce because it is exceptionally durable. The lumber undergoes both heat-treatment and a meticulous kiln-drying process, which extracts moisture to prevent the wood from warping, cracking, or bowing. This high-standard construction method ensures the foundation remains a stable, long-term support system for your twin mattress.


What is the benefit of a low-profile foundation compared to a standard one?

This 3-inch low-profile foundation is an ideal solution for modern sleep setups where maintaining a manageable bed height is a priority. When paired with today’s thicker, multi-layered mattresses, a low-profile base ensures the bed remains at a comfortable height for getting in and out of, while also providing a sleek, minimalist aesthetic suitable for contemporary bedroom designs.


Is this foundation a good choice for a child’s or teenager’s bedroom?

Absolutely. This twin foundation is meticulously hand-assembled to withstand the daily wear and tear of a high-use environment like a child's or teen's room. Its solid construction and upholstered finish provide a robust, quiet base that won't squeak, ensuring a stable sleep surface as your child grows.


How does the construction of this foundation support my mattress warranty?

To ensure total warranty protection for your mattress, a completely flat and rigid surface is required. This foundation is engineered with wooden slats placed closer together and cut a full inch wider than industry standards. This creates a sturdier, more consistent base that prevents the sagging or warping often seen with inferior supports, thereby preserving the structural integrity of your mattress over time.


Does this foundation require any assembly upon delivery?

No customer assembly is required for this item. Each foundation is meticulously hand-assembled by professionals before it reaches your home. This ensures that the structural integrity and precision of the slat spacing are perfectly intact, providing you with an out-of-the-box solution that is ready for immediate use.


Can this foundation be used with memory foam or hybrid mattresses?

Yes, this solid-surface foundation is specifically designed to meet the rigorous support needs of memory foam, latex, and hybrid mattresses. Because these mattress types are often heavier and require a non-flexing base to perform correctly, the reinforced spruce slats provide the necessary rigidity to keep the mattress layers properly aligned for optimal comfort.

39.00"w x 75.00"d x 3.00"h

4.4 out of 5 stars

Based on 804 ratings
5
75%
4
10%
3
4%
2
2%
1
8%
Sore No More

Great Quality

This review was collected as part of a promotion

The foundation is strong and provides the lift we needed.

Review provided by Tempur-Pedic

Reviewed On Aug 31, 2026
Happy Sleeper

Great Support

This review was collected as part of a promotion

The Flat Foundation is great support for the TempurPedic. We got the split foundation to navigate narrow stairs in an old house. My only regret is that I opted for the 5" instead of the 9". My last mattress felt like it sat way too high but the TempurPedic is a much more stream-lined mattress without a lot of fluff and bulk so the whole set up sits considerably lower. The 9" would have been a better fit but the 5" is fine for now. I have old dogs and this makes it easier for them to navigate the height of the bed. I do wish they offered a while version as the dark charcoal color is visible through my white linen bed skirt.

Review provided by Tempur-Pedic

Reviewed On Aug 19, 2026
Happy Sleeper

Ultra Low Profile With Superb Support

This review was collected as part of a promotion

Providing both functionality and support, this ultra low profile foundation turns any bed into a platform bed, but with the added support needed for a heavy mattress.

Review provided by Tempur-Pedic

Reviewed On Aug 19, 2026
happy buyer

does the job, looks good

This review was collected as part of a promotion

slim, does the job, and looks good.

Review provided by Tempur-Pedic

Reviewed On Aug 16, 2026
Mr. Guymandude

Nice foundation

This review was collected as part of a promotion

It looks nice, does the job, and wasn't too expensive.

Review provided by Tempur-Pedic

Reviewed On Jul 28, 2026