Replies

1. 
   forestgirl | Nov 16, 2004 09:20am | #1

   Can't help with the wood engineering questions, LOL, but to add a signature, click on  the orange "My Forums" button up top of this page, then click on "My Preferences".  Toward the bottom of that page, you'll find a Personal Signature section.

   Suggestion:  use italics, or a different color, or something for your signature.  Otherwise, it alway looks like it's part of the reply.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
   Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   BenM | Nov 16, 2004 04:22pm | #2

   I have a queen-size bed which uses slats to support the mattress.  The mattress spreads the load so you don't need a lot of slat thickness or a particularly strong wood.  My slats have a span of about 29-30 inches (there are two sets with a center support).  Each slat is about 1/4 inch thick and 2 inches wide.  The space between slats is about 1.5 inches.  I'm not sure what material they are but I think it's pine.

   I can't comment on the rail size without knowing the size of the bed or seeing your plans.

3. 
   joinerswork | Nov 16, 2004 04:51pm | #3

   Woodworker,

   The most commonly seen bed slats are usually 3/4" x 3", around here (VA), they are commonly yellow pine. Whatever the wood,pine or fir will work fine, it should be clear (no knots).I personally like to put them about 8" center to center.  If no box spring, I'll top the slats with 1/4" or 3/8" plywood, to keep the slats from printing the mattress.  You can make the ply in two or three pieces, it's easier to get it up a set of stairs that way.

   The slats rest on a ledger strip, around 1 1/4" x1 1/4" that is screwed and glued to the bottom inside edge of the rail.  You can attach blocks between the slats, to keep them from shifting out of place, or get the ledger out of wider stock and cut notches in it for the slats; you could screw each slat to the ledger.

   You didn't mention what size the mattress is.  For a queen or larger bed, I'd recommend a third support down the center, with a leg in the middle, to keep things from sagging.  Can be attached to the head and foot rails.

   For bed rails I like to use stout tenons, 3/4" or so thick.  They don't have to be very long, 1/2" to 1" . Your 3/8" tenons are probably ok, they wouldn't be easy to shear off, even if someone jumped on the bed, but I expect they will get crushed on their bottoms over time.

   Regards,

   Ray

4. 
   DougF | Nov 16, 2004 06:40pm | #4

   Woodworker,

   Having just completed, well almost except for the finish, a twin bed using Jeff Miller's guidelines, here is what I applied based on his book on bed construction.

   Rails: 6 " x 1 1/8"; Ledger 1 1/4" x 1 1/2"; slats 3/4" x 4" ( I placed mine on 5" centers); Tenons are 5" x 5/8" by 1/2" depth; bed bolts are case-hardened 3/8" x 6" ( buy them at nut/bolt or machine shop and pay $1.00 each rather than the $6.00 catalog price); and 2 1/2" corner posts.  The posts and rails are hard maple.  The head board and foot board are birds-eye maple and cherry panels.

   My ledger is secured from the side rather than from the bottom.  it is rabbited to insert into a 3/8" x 1/4" slot in the rail and then glued and screwed using #12 x 2" wood screws.  I agree with the other post that a center rail is necessary for queen or king beds. 

   The slats are out of some wormy cherry I had from end cuts.  They are dovetailed on the ends and I use matching spacers to keep the slats from shifting.  The dovetailed ends are my original contribution to the construction detail.  I haven't decided on whether to leave the spacers loose of screw them in place.

   That's what I learned - thank you Jeff Miller, wherever you are.

   Good luck with your project.

   Doug

   
   

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   Edited 11/16/2004 10:49 am ET by Doug

5. 
   mlbfreestyle | Nov 16, 2004 07:28pm | #5

   I made a queen-size sleigh bed a few years ago.  Most QZ size mattresses require a center leg to keep the center of the box-spring from sagging.  I did not want this.  I made slats from soft maple.  Approx 3 1/2" wide with a stiffening rib attached under each slat (to make a "T" section beam).  The bottom stiffener is about 3 1/2" tall in the center and tapers towards the ends so as not to be visible when viewed from the side of the bed.  The center is where the strength is needed anyway.  These slats are very strong.  I can stand at the center-point of one of these without any sag.  I weigh 200 lbs.  I made and installed 5 slats in the bed.  These are locked into a ledger strip that is approx 1" high attached to the bottom insides of the rails.  The rails are 8" tall.

   This system has plenty of strength to spare.

6. 
   JohnWW | Nov 16, 2004 08:46pm | #6

   From an engineering point of view, the primary purpose of the bolts is to hold the tenon into the mortise, all of the downward force is meant to be handled by the tenons.  I am not sure what size your tenons are, you only gave two dimensions, but based on the dimensions you did list, they sound small. 

   The tenons should be as wide as practical, around 3/4" in your case and project 3/4" to 1" into the post.  The height of the tenons isn't as critical, it could be either a single or split tenon taking up the available space after leaving clearance for the bolt or bolts. 

   The bolts you are using may be adequate, but they are definitely on the small size compared to the size of typical bed bolts.

   As to the weight the joinery has to handle, the weight of the sleeper is not the only load the joints have to handle.  It has been known that, on occasion, more than one person will sleep in the same bed, and that some times they don't just "sleep" together, creating a dynamic load far greater than the their simple weight, but further discussions on this topic will need to be taken up on a much different site.

   John W. 

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   Edited 11/16/2004 1:10 pm ET by JohnW

   
   

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   Edited 11/16/2004 1:12 pm ET by JohnW