Bed Frame Strucutral Question, Going From Queen to King
I am making Jeremy Zietz’s Contemporary Pencil-Post Bed from FWW #282 (not started yet). I was planning on adjusting the dimensions to make it a king size bed, this would require adding 16″ of length to the headboard, footboard, head rail and slats. The plan as is does not require any supports under the slat such as a center leg, relying on the side rails to carry the load. My questions are:
1. Should I add additional support under the center middle slat?
2. Should I beef up any of the other structural components to accommodate for the extra 16″ of width?
The plans as written call for 1 1/4″ thick side rails, head rail, and footboard. And 7/8″ headboards. The slats are 7/8″ thick and have a 2 1/4″ by 2 1/2″ beam glued on the underside. Lastly, the bed was made with Ash, I plan to use Cherry. The slats call for Poplar, which I will use. See photo for reference. Thanks.
Replies
That is plenty strong to be extended to king size, I made a King size bed with the same concept and it is plenty strong, the only difference being the slats, they are 1\2 inch X 3 inches ash inserted in mortises in the side rails and they curve upwards over a center beam going from the headboard to the baseboard supported by a center leg . This compensates for the inevitable sag of the mattress towards the center.
Center support is a must imo. It's an easy addition and won't take away from the look of the finished piece. 7' is a long stretch to not have any center support. I used a 2x4 with 3 4x4 feet when I built my king frame and it's rock solid.
There will be some spring to the slats. Many of us have become accustomed to the rock solid feel of the platform that replaced the old "box springs" part of a bed long ago. Just something to consider if this will be your nightly sleeper. A simple center support would pretty much simulate the platform feel.
I've kingsized Zietz's bed (with different headboard) and simply lengthened his specs to kingsize but otherwise kept the rails and slat dimensions the same. Plenty sturdy. I did add a center beam which I found a must.
When I build one in the future I will keep the box spring just because I'm tall and I like the extra height. So I plan to keep the overall height of the bed at or around 27". So the height of the headboard is important. So with this in mind I'm not overly concerned with the strength of the slats unless I entertain a rather large girl.
Might want to check the mattress warranty. Some require a center support.
Given the ease and economy of adding a center support to the poplar slats:
1. Yes 2. No
the center beam is 5 X 1 Hickory notched to receive the slats and has a center leg support.
I also made used this plan as a base for a mid-poster and upsized from queen to king. I agonized over the same question but ultimately found that the substantial stiffeners attached to the lower side of each slat were enough to keep the bed from sagging and the side rails are more than adequate to accomodate the extra weight. Have been sleeping on that bed for about a year now.
I'm not disagreeing with the folks that say adding a center rail would be useful as easy as it is, although you would need to account for that by separating the stiffeners into two pieces, but I did not find it strictly necessary.
The stiffener goes under the slats, no need to separate them.
Thank you for the insight, very helpful. Since you made this already perhaps you can help me solve one other question on the plans that has me confused. The plans call for an unglued spline connecting the two pieces of the headboard. Why is the width of the groove for the lower piece 3/16" while the width for the upper piece is 1/4"?
I wondered the same thing and didn't come up with a good answer. It didn't seem necessary to have extra room for alignment, so I ended up cutting them the same. I used a plow plane with a 1/4 inch iron on both the top and bottom pieces of the headboard and had no issues with alignment after sliding the spline home.