Replies

1. 
   HowardAcheson | May 08, 2005 07:55pm | #1

   You can't do it unless your parquet pieces are 1/8 thick or less.

   Solid wood expands and contracts across the grain with changes in moisture content. There is little or no movement along the grain. Therefore the blocks will want to move to get wider but be restricted by the cross grain pieces it is glued to. You will end up with the gluelines failing or the wood splitting.

   If you glue wood thicker than 1/8" to a composition substrate (that doesn't have any wood movement) you will end up with split or failed parquet and/or warping of the tabletop.

   Here is a picture of some of the type of thing you will end up with.

   Howie.........

   
1. 
   DAC | May 08, 2005 11:45pm | #2

   Thanks Howie....  initial response.. OUCH!!  

   So, from your experience, I'd almost have to use thick "venier" -- whatever is the correct term for 1/8in or less thick.. to keep the top from catastrophe.   Hmmm.. any possibility of using the table top as a large floating pannel inside a frame?? sort of like a standard cabinet door??  allowing the whole thing to expand into a frame cavity?  

   dac

1. 
   HowardAcheson | May 09, 2005 07:32pm | #3

   Your primary constraint is that you can't have solid hardwood with the grain running in two different directions. That's what caused the problen in the picture I posted. In other words, no alternating grain parquet type configution. You can have the hardwood in smaller lengths with the grain all running in the same direction though.You can certainly make a sort of laminated cutting board pattern for the center and frame it with something. But, it will have to be engineered so that the center can freely expand and contract just like a frame and panel construction.Howie.........

1. 
   Woodhead | May 09, 2005 10:30pm | #4

   Howie, your post is very timely. I'm in Australia and was thinking of making a "parquet" type table top from the numerous 50 cm (about 1 1/2 feet) lengths of Jarrah hardwood that have slowly collected as a result of "offcuts". I was thinking of gluing (epoxy) offcuts that are say 35cm long by 130mm wide (about 5 inches) by 40mm thick (1 1/2 inches) (I have a hard time thinking in inches etc...) into two rows about 2 meters long. Then joining these two rows via a central board down the middle of the 2 meter table top (also 130mm wide, 40 mm thick). Then to add insult to possible injury... I was going to glue side boards (also 130 mm x 40 mm) down both the long edges of the table, and across the short ends. So that there was little end grain showing and provide a "framing" effect. This design is not exactly parquet, but do you think I'll face the same expansion / movement problems?Appreciate your feedback.Richard

1. 
   HowardAcheson | May 10, 2005 05:25am | #7

   I'm not sure I understand what you want to do but the basic rule is that solid wood expands and contracts and you can not do something that will hinder that movement. Anything across the grain will impede the movement. Gluing solid wood to a composition material substrate that does not expand/contract will cause the assembly to warp, crack or both.Howie.........

2. 
   Yogi | May 10, 2005 05:34am | #8

   Peter raises a good point/question-  How do those hardwood floors avoid the problem?  They're not glued, but certainly securely fastened-

3. 
   IanDG | May 10, 2005 06:04am | #9

   I'm reading this thread with some amusement -- having glued tens of thousands of square feet of 3/4" thick hardwood block parquet to substrates that included concrete, plywood and particle board without problems --- as, of course, have many other tradesmen over the past 2-300 years or so.

   The gaps shown in the floor in the photograph look to be caused by expansion across the grain of the field -- in other words, where the boards are side to side -- pushing the border apart.

   Parquet patterns are designed so that the expansion is evenly distributed -- herringbone is a good example of this -- so a table top built on this principle should actually be more stable.

   IanDG

4. 
   HowardAcheson | May 10, 2005 06:27pm | #10

   In addition to what Ian has said, if you look closely at many solid wood parquet and herringbone floors, you will generally see where the boards are not completely closed up. And, spacing may change as the seasons change. Slightly open joints are not as noticeable in a floor but are more prominent in a tabletop.Herringbone patterns are relatively safe but the overall panel must still be allowed to expand/contract freely. It can not be solidly enclosed in a frame.Let me say that in the shop I was involved with, we made many veneered panels with very interesting and unique patterns. You can do this with veneers--and most furniture you see with panels like this--are done with veneers. Solid wood just does not last unless you pay close attention to wood movement.Howie.........

2. 
   Peter36 | May 10, 2005 12:03am | #5

   Personally I would say that you can do it. I would not glue the pieces down, I would just nail them like you would in a floor installation. I would say that the problem with the picture in Howie's post is the floor glued together. They don't look like individual pieces of flooring where the expansion and contraction is not so radical. Hardwood flooring installers do herringbone patterns, and other alternating grain patterns all the time with no problems.

1. 
   DAC | May 10, 2005 03:50am | #6

   Our entry way has just a haringbone pattern -- which is how I got thinking about this table top.  I'm encouraged by your comment that floating within a frame might work... now just have to decide to go with a more simple geometric pattern, like the haringbone or try for the parquet -- still floating within a frame.  I'd anchor the frame to the underlying pylwood base to keep the table tied down as a whole..

   wow...  glad I posted the question..

   dac

3. 
   Peter36 | May 11, 2005 12:59am | #11

   Hello again dac. When you have made your panel [the center field] make a tongue on it all the way around and fit that into a groove cut on the inside of the mitered frame. Make sure the panel won't bottom out when expansion occurs and the tongue is large enough to stay in the groove when contraction occurs.            Peter

1. 
   DAC | May 11, 2005 05:06am | #12

   thanks Peter36! ... 

   Your approach is what I was thinking of...floating the tongue into the frame ... good reminder not to let the tongue bottom out...  

   Pardon my next question though...   I was thinking of fastening the adjacent pieces with either "toe nailing" with a brad gun or glueing one to another... but not necessaryily glueing down to the plywood base.   Does this make sense??

   dac