Our Foam Bed's Foundation

Almost complete foundation, still needs a cover.

This is the fifth post in the series of six articles detailing the steps we followed building our polyurethane and latex foam bed. See the links (right) for other steps.

This post is about building the bed's foundation. The foundation is the bed frame (or platform) plus the layers of polyurethane foam that give the bed height and upon which the support and comfort layers rest.

The foundation layer could be a simple plywood platform but since we already had a beautiful white oak bed frame that originally held a conventional box spring we wanted to adapt the frame for our new bed.

The original bed frame had three fairly flimsy slats that held up the box spring. This worked ok because the box spring had its own rigid frame that sat on the slats. This arrangement  would not work however for the foam bed because the foam layers of the foundation needed more bottom support.

Kiln-dried 2x4 foundation slats and centre brace

Rather than using a solid, and hard-to-move, plywood platform I built a system of kiln-dried 2x4 Douglas-fir slats and a centre floor brace.  I used kiln-dried wood so the slats would not shrink in length as they dried and possibly pull off the side rails. The brace is made from the same material as the slats with a top and bottom head and short "studs" about every 30". The slats are loosely laid on the side rails of the bed frame except for the middle slat which is screwed into the rails which prevents the bed frame sides from bowing outward.

Slat and brace detail.

Next, we placed 7 inches of ILD 50 (very firm) high density (Lux HQ) polyurethane foam (see photo above) on the slats. Seven inches was the depth needed to bring the level of foundation foam to the top of the bed frame side rail (see photo above). The foundation foam was bought in two pieces, a 3" and a 4", from the Foam Factory (foambymail.com). See the earlier post about sources of foam for details about how foam was bought and shipped.

The seven inches of HD polyurethane replaced the conventional box spring at a cost of about $220. This is about twice the cost of a cheap box spring but will likely last much longer, has no springs that could break and damage the upper layers of foam, plus is very easy to move.

The final step was to cover the foundation polyurethane foam with an old sheet for protection. The next step in the project is to add the support and comfort layers.

If you have questions or comments contact us through our 'Bugs website of leave a comment below. 

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