Replies

1. 
   JohnWW | Mar 16, 2004 01:06am | #1

   John,

   You have good reason to worry.  In any species of wood, the amount of wood movement is entirely dependent on the grain orientation, that is whether it is quartersawn or flat sawn, and the relative humidity in the driest time of the year and the most humid.  The counter's finish, how it was dried, and the moisture content when it is delivered are irrelevant.

   If the counters are flat sawn and installed in an area with dry indoor air in the winter and humid summers, they'll move about 5/8 inch between winter and summer.  There will be less movement for quarter sawn wood or if the climate doesn't have as big a swing between summer and winter humidity levels.  I'm basing this on the typical values for pine, I couldn't find a specific listing for pitch pine. 

   The simplest way to allow for the movement is to fix the counters where they touch the wall and allow the overhang along the front edge of the counter to move with the seasonal change.

   Make up the right angle joints as simple 90 degree butt joints, don't use a 45 degree miter, it will unavoidably develop major gaps as the counters move.  Where two pieces of counter come together at the corner they have to be free to move independently but still stay attached.  There are several ways to do this but it has to be thought out or you'll have trouble later on.

   Generally wood does not make a good countertop for kitchens, which is why it is rarely used even in high end installations.  I'd try to talk the client out of it if possible.

   John W.

2. 
   art | Mar 16, 2004 01:27am | #2

   I had a similar situation where a client insisted on a knotty pine counter top to match the cabinets. I tried to disuade him, but to no use. I used a 3/4 plywood base and fastened the top at the front edge and affixed a hard maple edging. I made the backsplash out of 5/4 stock and allowed the top to expand and contract under it. I used silicone between the bacsplash and the top and fastened the backsplash to the wall. There was a butterfly sink at the L junction, so a 45 degree connection was the only option. I used three of those connectors that you rout into the underside. It has not been quite a year yet, but I've not had a callback. Good luck, Art   

3. 
   mike4244 | Mar 16, 2004 03:41am | #3

   Ten years ago I built a vanity and the top from clear pine. This was for my daughter, tried to talk her out of the pine top. She wanted the top out of pine, I consulted a wood finisher for advice on finishing the top. I wound up putting on five coats of Varathane varnish, two coats underneath. Ten years later the vanity top is still in excellent condition. There were no miters, just three boards glued up to 25" wide, 48" long. The top overhangs the cabinet about 1", never checked the overhang from one season to another but I am sure it moves somewhat.

   mike

4. 
   Pertz | Mar 16, 2004 02:12pm | #4

   I've made two wood countertops so far, one of maple, the other of cherry, and have learned various lessons, mostly starting and finishing with the reality that the wood will most definately move and that you must allow for this above all. You'll have to decide which way you want the expansion to go, and, given the corners, it looks like the best idea is the wide backsplash with room for movement underneath it. So, the top gets fixed at the front edge, and moves at the back. Finishing four sides is also crucial, though nothing will actually keep the water from moving in and out of the material, just slow it down. I'm about to do another out of Cherry for our own home. We love the material so much we don't really care if cracks develop (they will) and we'll just fill them with glue and sawdus as they develop, then watch the whole thing swell and crack next season around. I guess we're just not that fussy about the reality the wood moves.

5. 
   ian | Mar 16, 2004 02:33pm | #5

   John

   Till I ripped it out about 6 years ago to put in a new kitchen, I had wooden counter top.  I'm in Australia so the timber would have been an Australian hardwood. 

   The counter was L shaped, the upright portion was about about 2in thick, 2 ft deep and 13 ft long and the leg about 5 ft long.  The two pieces were joined at right angles with the 5 ft section acting as a sort of "bread board" end to the long section.  the Breadboard joint was fixed to the long piece with two metal table connectors which from memory were fitted into slotted holes.  The top basicly floated on the cabinets, much like a workbench top.  (SWMBO made me dispose of it before I could reuse it as a workbench.) 

   My counter was made of laminated strips, each about 1in by 2in and glued, I'd guess with an epoxy.  I'm not sure what finish was used.

   hope this helps.

   Ian

1. 
   IW | Mar 17, 2004 01:48am | #6

   I've done 4 counters in wood over the last few years, each of a different species.  At first, I was very reluctant to do them, too - tried to point out the benefits (and ease of installation!) of plastic laminates on man-made substrates!

    Two tops were 'U' shaped, the other two were 'L's'.  The L's were relatively easy to allow for seasonal movement - did what a previous poster suggested and allowed for most movement to occur under a backboard about 5/8" thick.  The joints were butted, but I had a full roundover on the fronts, so I had to have a small mitre to join the front neatly.  I used a full-floating spline to keep the top surfaces level, and screwed the fronts firmly to the carcase, but allowed the backs to slide a bit.  On final assembly, I put a thin bead of (flexible!) silicone sealant along the top part of the join.

   Most of the joints have held perfectly. (I live in a part of the world where very little heating/cooling is used).  I have noticed that the tops expand and contract less than expected based on the information I had. (Have noticed this with freestanding furniture, too - the wider the board, the smaller the expansion/contraction as a % of the total width - this may be due to smallish number of samples, so I suggest you always allow for worst-case and be thankful if movement is a lot less than anticipated). One counter has ben in place for about 8 years, and is in excellent condition - the joint is still level and tight.  A second (4 yrs) which has two joints, opens a bit toward the front each year on one of the joins (less than a 32nd, but you can notice it if you look).  The silicone seems to stretch enough, and keeps it clean.  The other two are not where I see them any more, but haven't heard of any catastrophes with either of them.  The finish in all cases is polyurethane, thinned and wiped on (many coats!), and all surfaces (including ends) treated. Wiping is the easiest way I've found, to get the required surface quality on the job (spraying is usually impractical).

   Much has been said about durability of wooden tops in previous threads, and all I can say is that both tops I see on a regular basis have held up under normal family use (kids plus adults), and look in great shape.  More than I can say for a many plastic laminate counter tops of similar age. Neither species is particularly hard, in fact a bit softer than Cherry would be my estimate.  If you can respect an ordinary dining table, you should be able to cope with wooden counter tops. 

   I'm sort of a convert -  recently put wooden tops on my own kitchen.  In the right situation, they sure look and feel a whole lot nicer than plastic!

   Cheers,  IW