# Help! Warped table top



## arlodaniel

Hi! I am brand new to lumberjocks, but have read many posts with great interest and am continually impressed by the level of knowledge and willingness to help that I've noticed!

I've just completed a farmhouse table based more or less on these plans: 
http://ana-white.com/2012/11/plans/farmhouse-table-updated-pocket-hole-plans










I used kiln-dried fir, and allowed the lumber to acclimate to my apartment for a week.

And yet, in preparing to attach the tabletop to the base, I discovered that the tabletop (made of 4 boards joined with pocket screws and capped with breadboards) is warped such that the two *opposite* corners float above the legs:









I thought I could simply clamp it down and screw it in… but unfortunately as I clamp the opposite corners, rather than pulling the tabletop down to meet the base, it lifts the base up to meet the warped top, so that one of the legs ends up about an inch off the floor!

I could just put a shim under that leg, but it's a big enough distance that the table will then be on a noticeable angle; I suppose I could put 1/2" shims under the two opposite legs but, again, not ideal.

Thoughts I've had:

1) Leaving the warped wood on the cement floor overnight with weights on the corners.
-Did that; ineffective
2) Wetting / steaming the concave side to make it expand
-I don't really quite know how to do this, especially as the warp is on an angle so I'm not certain where to apply the water. And I don't think I have the necessary tools to steam it.
3) Kerfing?
-I don't know much about this option, but it sounds maybe promising? If I could kerf the bottom correctly, maybe I could more easily clamp it down and screw it on without it pulling up the legs? But, again, I'm not clear on exactly how / where to make the cuts; cutting corner-to-corner at an angle across the boards somehow doesn't seem right. (I have a skillsaw, by the way, no table saw)
4) Disassembling
-I have a feeling I will get this suggestion, but I'm not going to do it. First of all, I don't even see individually warped boards, just the whole thing seems cupped. Secondly, I joined it as straight as I possibly could the first time, taking hours with each joint to make sure that it was as flat as possible before I put in the pocket screws; it's not going to be any better next time around. Thirdly, this project is to be ready for Thanksgiving next week-and I'd rather just suck it up and shim it than take out fifty screws and scrape out the epoxy/sawdust filler I used in the seams and probably have no table next week 
5) Anything else?

Thank you so so much for any advice or suggestions!!


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## a1Jim

Your construction does not allow for wood movement ,so when the wood moves due to atmospheric conditions it is going to crack ,warp or twist. Pocket screws is not the best way to connect a table top.


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## a1Jim

Here's some info that will help
http://www.finewoodworking.com/media/TabletopsFlat.pdf


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## Micahm

I don't know much, but had and idea. If you could take it somewhere and the keep pouring boiling water on it and get a clamp to clamp it down little by little. I don't know if it would work, as I am a beginner woodworker also, but just had that idea. Not sure if you would be able to do that though.


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## a1Jim

Unfortunately there are lot of plans out there buy companies and individuals that don't know what their doing, even a long standing woodworking tv show does not build things taking wood movement into consideration . Just because pocket screws are an easy way to accomplish joinery does not mean they can be used for all applications .


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## wormil

Kerfing would help as it releases stress but I would save it as a last resort. Try moisture first. You might try laying it concave side down in the grass for a few hours. I would not shim it as that will look like failure.


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## Tennessee

You've made two mistakes that I can see. First off, Jim is right, you have to allow for movement. If you look at the very first picture in that pdf. file he listed, you can see how that construction will allow for movement.

But let's talk about the movement itself, and some ways to minimize it.
It starts with picking out the wood. 
Flatsawn wood will warp the worst. This is when the board is simply lopped off the log, with no consideration taken of grain direction. I've bought wood like this many times from local people who own portable tree bandsaws, and to be honest, I just know about 15-20% of it will warp way more than acceptable unless I rip it down and try to keep it flat and stacked.

When you pick out your timbers at the lumber store, which is what these look like on your project, you should have the growth rings on the ends of the boards come in and leave the same side at about 45'. Think half-moon. This is basically quartersawn. That's about the closest you'll get with big box lumber. Then, when you put them in a row as your project calls for, you MUST flip every other one, in other words have rings facing up, next one down, and so on. This will not cure all warp, but it will cause the boards to fight one another and keep some semblance of order. The end board is what holds all of them together, and there is a reason why people use dado joints to put these on, not pocket screws. It allows for a little movement, and holds the boards firm in the middle of the board. Pocket screws come in from under, attacking only one side of all boards. They don't allow for movement, so the whole top starts to move.

At this point, I think you have to think in terms of taking off the breadboard ends, making sure every other one is flipped, and start over. 
Then you should attach it to the lower stringers and legs with the attachment blocks you will make like the ones in the picture shown in the article Jim listed. Sorry…


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## wormil

Many people believe that alternating growth rings is a myth, I'm one of them. Well I shouldn't say myth, but that by alternating you end up with warp instead of cup or bow which are easier to remove.


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## Tennessee

Interesting. I have to be honest, I've never talked or met with a woodworker that thought that, until I read your post. I must have dozens of articles and books where they talk about alternating growth rings. Well, people also used to think the world was flat, so maybe we're all wrong.


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## Tennessee

Ah, you changed up on me while I was typing…I would agree that it is not a cureall for the warps. It is much more suited for cupping. But to me, if two or three of the boards all had the growth rings facing the same way, it would be easier for the multiple cuppings and any warp to work together.
It's not guaranteed, but I bet he got the boards all off the same stack at a big box store. That makes their chances of coming off the same set of logs higher. They would all share the same warping/cupping tendencies.

I guess I'll just keep on alternating. Old habits die hard.


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## wanderingwest

Seeing the doug-fir here made me think of crowning the apron which is something I would do when laying joists or building trusses but never thought about with a table. Would that work too? Just a thought.


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## Tennessee

If you mean re-leveling the apron to match the top, that would be something I've never seen done.


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## wormil

I've never bothered alternating growth rings in the half dozen or so tables I've built nor in the benchtop and the only one that bowed or cupped was a small side table that someone placed over a heat register. The heat dried out the bottom and cause the top to bow. That was also my first table and I used 3 coats of finish on the top but only 1 sealer coat on the bottom. Had I finished it properly it might not have bowed at all. Basically I believe that orientation of the growth rings is trumped by many other factors.


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## wanderingwest

I mean using the warp of the apron to counter the warp of the top and pull it straight. There's a ton of situations in framing a home where you would us that technique but I just never thought of it being an issue with furniture. I just thought of it seeing the soft wood here.
http://greenwoodconstruction.us/%20/191/crowning-your-lumber/


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## a1Jim

I think the article in fine woodworking covers the subject very well .I think it's important to know that although selecting quarter sawn wood will help it does not element wood movement all together and even though the school of though has been that it's alternate plain sawn wood with alternating up and down end grain pattern it is not always necessary and still does not stop wood from moving,it's more of a precaution to help keep tops some what flat. I know others have offered an answer to your question about flatting your warped wood out but it still won't help if you don't let your wood move. One of your above questions was if having your wood on a concrete floor can affect your wood,the answers is yes. The reason being that concrete holds a good deal of moister and laying a board directly on a concrete floor inparts moister to one side of your wood while the other side of the wood is dried by the air,this is exactly what causes wood to warp. I'm not trying to give Paul a hard time but quarter sawn wood has it's grain at 90 degrees on a boards edge like the photo below


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## Tennessee

You are right, Jim, but when was the last time you saw a board like the one you show in a pile of fir at your local HD or Lowes? Your picture is true quartersawn. The banana ring pattern is usually about as good as it gets with these fast growth trees they cut up now for "kiln dried fir".


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## a1Jim

Paul 
It takes a lot of searching to get quatersawn and rift sawn wood in dimensional lumber but it can be done I helped a student do it a little while ago for a bench he was making, we were at HD over an hour sorting through the material they had,but it's defiantly not easy.


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## wanderingwest

I have to get off my computer here at the library in 5 minutes but i have a quick question for jim. In the picture at the top it looks like the apartment is off the ground floor. If the concrete floor is not sitting on soil and has no issues with hydrostatic pressure pulling moisture up from the ground will there still be a problem with moisture.


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## Tennessee

You are a patient man, a1Jim! You must have a better HD than I do. I had to build a stand for hanging my chimes at a local show, went through maybe 200 2X4's trying to get six that would not warp. After it was all said and done, two still warped.

Either way, I think it is safe to say that the person we are supposed to be helping here has numerous problems, including pocket screws, warped boards, and a Thanksgiving dinner in seven days!!


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## a1Jim

Your right Paul ,I don't think you could glean enough quarter sawn and rift material every day,we went through 2×4s,2×6s in a number of varied lengths to get what we wanted.
I agree on the cause of the problem. Lets hope our friend can get a good fix between now and Thanksgiving.


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## a1Jim

Wanderingwest sorry I missed your question. I believe that even concrete not in contact with the ground still holds moisture but not as much ,so even though the percentage is less it still will cause an imbalance in the moisiture content of the wood. Just to take this a step further even wood layed on to of a wooden bench will have an inblance of moisture if on side of the wood is flat on a bench and the other side is exposed to air,even this can cause cupping and twisting in wood,this is why when your letting wood acclimate to your shop it's best to have stickers between your stacked wood.If you can only store your wood on a concrete floor I would put a layer of roofing felt down first then stickers then wood.


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## renners

With regard to thanksgiving dinner, you might be as well buying a sheet of MDF and using that with a table cloth to get you out of trouble, as for fixing the table top, what tools have you got? I'd be tempted to rip down the glue lines and rout out for a loose tongue in each board where it joins, reassemble without glue or pocket screws and loose tenon the breadboard end on, glued only at the ends and the middle. Then add some rails underneath connected to the aprons with slotted screw holes to attach the top to and allow movement.
Also, run your finger over the edge of the breadboards, are the planks now inside the end of the breadboard? If so, I would say the timbers have shrunk rapidly from being taken from the Borg to your heated apartment. I could say 'should've let them acclimatise' but what's the point?. It's done now. Chances are you could do everything in your power to fix this now and it'll still warp in a couple of weeks time.


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## pintodeluxe

Try using 4 long clamps. Instead of clamping the top to the apron, run the clamp to the bottom of the leg. This should at least close the gap so you can attach some figure 8 fasteners.

The long term success of breadboard ends depends on their ability to let wood contract and expand across its width.


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## rexb

I just wanted to mention that this same issue has been pointed out before with Ana White plans. The breadboards aren't really breadboards at all, just disasters waiting to happen.

It's a shame, because it is a nice looking table and her site gets lots of readers, but this type of table just isn't meant to be built with pocket screws.


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## casual1carpenter

arlodaniel, you do not say where you bought the fur lumber or the moisture content. SPF from the big box stores is known for high moisture content and is not known for stability. You totally rule out the "Disassembling" approach as you need for thanksgiving dinner is why you built the table. The trestle design of your table does not have the ability to resist racking to straighten your top.

All that said, I wonder if you were to make a diagonal brace consisting of four or five pieces of 3/4" plywood ripped straight to your apron height - glued and screwed every layer - and attach this to the underside with properly drilled lag bolts and washers. It might help reduce the warpage at least so your guests can be provided with a near full beverage glass. This would not be my first choice of method but I do realize that you may need something and have already expended quite a bit of time and effort and that you might be a bit frustrated and you still need a table. No guarantees on this working, it is just a random thought that might help.


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## rexb

I think renners has the right plan: temporarily screw down a sheet of mdf or plywood as the top and hide it with a tablecloth. Then later you can rebuild the top using a more stable method of construction.


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## Benvolio

If it was me (and I know this is drastic), I'd completely remove the table top - rip it down the middle of its length and re-mill the timber now you're a bit more clued up on accounting for wood movement.


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## wormil

If you want to fix it for the short term, make heavy battens the same height as the apron, short enough to fit inside the apron, and screw them to the top which should pull it mostly straight. Then attach your tabletop. I haven't looked at the Ana White plan so I don't know what other problems it may have but this might at least get you through Thanksgiving then you can look at longer term solutions.


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## Sigung

Hey I'm brand new to woodworking, so you should take whatever I say with a grain of salt. That being said, my first thought was, when you get the table to a stable environment where it's not likely to warp any further, couldn't you just plane the bottom flat. I know it sounds simplistic, but I've had great success doing this type of thing with a jack plane and a jointer plane.


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## a1Jim

The problem is Jerry wood is hygroscopic and want's to take on water one part of the year and the other part of the years it lets water go ,this make the wood expand and contract aka wood movement. This happens indoors and out to different degrees . This is why you have to plan on wood moving,if you don't plan for it you can have lots of trouble with pieces you make. Like our friend hear did.

http://en.wikipedia.org/wiki/Hygroscopy


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## Sigung

Thank you Jim, I think I'm going to learn a lot from you.


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## arlodaniel

Hello all,

Thank you so much for all of the helpful, informative and speedy responses!! I want to address specific suggestions, and then update you all on my (lack of) progress!

Jim: That pdf has lots of great info; thanks. Although based on what it says, it seems okay to attach a fairly narrow tabletop to a base with pocket screws (?). Those buttons look like a great technique for future use, though. It's interesting that the writer says: "after 40 years of gluing up hundreds of tabletops and thousands of panels, I find that grain orientation really makes little difference." So he may be agreeing with Rick's perspective.

Tennessee: Great to know about quartersawn v. flatsawn. I live in an apartment in Manhattan and have limited access to good lumber supplies… so I had mine delivered from a lumber store in New Jersey, sight unseen. Next time maybe I'll invest in some lumber that's intended for something other than rough framing. Any suggestions for what kind of place to get good, furniture-grade wood? Would that not be just a normal lumberyard?

Renners: I think I'd prefer just shimming it and dealing for the time being; next time maybe I'll try my hand at M&T. I did let the planks acclimate for a week before beginning to work. Is that not long enough? The planks did indeed shrink so I cut the breadboards shorter accordingly.

Pintodeluxe: Running a clamp to the leg will cause the same issue as running it to the apron: it pulls the leg up to the top, rather than the top down to the leg. If I could only fasten the legs to the cement floor so they wouldn't move, I'd be set! 

casual1carpenter & Rick M: I fooled around with battens and other braces all evening… honestly, I think the warp is too slight (one corner about 1" lifted on a 96" table) to be perfectly straightened out by that method. Though maybe it could work if I did it right?

*Overall update*

So, while I appreciate all of the tips regarding construction of the base, the primary problem now is not how the top is attached to the base (it isn't yet), but the fact that the top itself is not straight. I'm blaming pocket screws and their tight, inflexible connection. But I don't have the time to take it all apart and rejoin. And I don't imagine just loosening some of the screws could help??

My uncle gave me an interesting and handy approach:

Flip the table over: screw a really strong eyelet (or two-hole strap) in each of the two opposite convex corners; run a non-stretching aluminum cable ("aircraft cable") through these eyelets and over a 4×4 (or larger block) in the middle of the table to make a triangle pulling the eyelets in and up. Attach the ends of the cable to a turnbuckle, and tighten it until it pulls the corners up.

I think they use this on wooden gates? I don't know if it's the best technique for tabletops, and I really don't want to have a wire and block under the table forever, but it's an interesting idea-and I'm hoping it could reduce the warp at least temporarily, even when I take it off? Or perhaps this is wishful thinking… I'll see how things are tomorrow.

So, is the consensus that one should use mortise and tenons for joining tabletop planks? Glue without M&T? Something else? I have a better understanding of good ways to connect a table top to a base, but still am not clear on how to account for seasonal movement in the construction of the top itself.

Many thanks!!


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## arlodaniel

Oh, and I forgot to add: I took off the breadboards, thinking it would be easier to straighten the top that way, but it unfortunately didn't help.


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## pintodeluxe

Normally planks are edge glued together. Biscuits are optional.
Breadboard ends are different, they need to be attached with mortise and tenons. The breadboard ends are only glued at the center to allow the table to move.
Here is a discussion on breadboard ends… http://lumberjocks.com/pintodeluxe/blog/31777


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## hydro

To the OP- Sorry for your issues with the table top, but I see basically two serious problems; one in design and the other in materials (execution looks very nice however).

First, as mentioned above, the pocket screws/breadboard end idea is just wrong. The wood needs to be edge glued and then the entire top needs to be allowed to slide within a groove in the ends. That top will move as expand/contract as 1/4" between seasons if you have humid summers and dry winters. A dovetailed breadboard, pinned in the center only will allow this this movement.

Second, You used construction lumber, a big No-No if you are looking for dry and stable material. The home store stuff is normally stamped "S-Dry" which means that it was dried to a little less than 30% moisture at the kiln, or just below where there was liquid moisture in the wood cells. If you use it that way it will continue to dry once assembled, causing the movement you are seeing. There is no way to avoid this. It takes up to a year for "2X" lumber to reach equilibrium moisture indoors (about 8-12% moisture depending on where you live), and if you want to use the construction grade stuff you will need to let it age a long time indoors before using.


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## rexb

Hi again. We haven't all been entirely clear with our responses, but what everyone is trying to say is:


Joining the long planks with pocket screws is fine. Joining the breadboard ends with pocket screws is not fine and is what caused the problem.
Since the problem is inherent to the design, anything you do to straighten out the top now will only be a temporary fix - it will warp again with the next seasonal change.

Good luck!


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## donwilwol

And forcing the top into shape will probably crack it.

and one more thing that wasn't mentioned. 1 week for. 2" lumber is no where's near enough time to truly acclimate.

if you don't have time to take it apart, it will just never be right.


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## 680

I have made a couple of these tables and yes I used the same website as this gentleman did. My first table had the same problem. Of course I found out after I had finished it and tried to secure the top to the base. I tried the usual fixes but the warping was so bad I decided to destroy it and start over. I was more careful with wood selection the next time and the table still warped but it was minimal and a small shim and some felt padding cured the rocking.

I won't ever use big box store wood again to make a piece of nice furniture. lol

If you guys were going to join 8/4 planks together what type of joinery would you use? I just bought a doweling tool.

Also, what would you use to join the 8/4 top to the base? I used pocket screw the first time but would like to try something different.

Thanks

Thanks


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## Buckethead

I would simply joint the 8/4 stock, then glue and clamp it. If you don't have the tools/experience for this, pocket screws are fine to join the planks for the top to each other. Just not the breadboard.

As for attaching it to the base, pocket screws are fine, but I would suggest enlarging the screw holes to allow the table top to expand/contract seasonally. (especially at the ends of the table. The aprons could theoretically move with with width of the top at the center of the table, but I'd for allow movement there too). Also, don't tighten the screws too much. Just barely snug as the table top rests on the base.


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## MrKnowItAll

I would start by taking your top off. Granted, that may make your dinner guests a bit uncomfortable.


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## RogerM

To salvage this top I would suggest cutting a series of kerfs in the boards you glued together (the more the better) . Cut the slots at least 3/4 of the way through, don't cut through the ends, and avoid the joints. Clamp it up again and see if this will resolve the issue you are having. SInce the cuts are on the bottom they won't show. Remember - wood will do what wood wants to do. Forcing it rarely works.

I would be very interested in knowing if this helps.


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## Sk1pp3r

Would using biscuits or dowels for the planks work any better than pocket hole screws? I am in the process of making a similar table and have the edges of the planks planed smooth. I'm thinking of leaving the biscuits in loose like a loose tenon and doing the breadboard end with mortise and tenon.


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## Knothead62

Pocket holes and screws for joining the boards but letting the top "float" on the apron? I recall seeing some little figure 8 clips at Woodcraft for doing this. What do you experienced WWers think or what do you do? Thanks.
BTW, arlodaniel, good question for the forum!
Put the table aside until you get it fixed and eat on the floor like the Japanese.


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## 680

I have used the s clips before but I don't think they would hold. The base and top are pretty heavy. I don't know if it would hold very well.

Im gonna try 6/4 ASH this time.


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## DavidIN

if i want something straight-ish from store bought wood i take the piece and cut it into strips, maybe 3 for a 2×4, then turn the pieces 90 degrees and reglue them. much more stable. the panels would do better glued, no M & T joints or anything needed. nor pocket screws. i like screwing in runners on the inside and screwing through them into the top….with holes larger than the screw so it can move (very impportant). if the hole is bigger than the head of the screw use a washer. unless you take it apart that is the only way i would know to fix it…..screw in runners on the side rails, pull the top down with a clamp if you can, then screw through the inside runner into the top. depending on the strength of the wood grains it might hold. or you could epoxy the screw holes, but that is a whole different topic. if able use a harder wood for runners and 1" by 1" or so strip to attach to inside. beafier the better and predrill the holes so you don't split the runner.


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## DavidIN

sk1pp3r, you don't need anything but glue for panels. its stronger than wood when cured. biscuits for alignment only if you like, not needed. already mentioned once, but only use glue on a breadboard end in the middle so the wood can expand and contract.


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## DDWW

I know this is an old thread but this link might help with understanding the alternating growth rings in glueing up a table top.

https://www.canadianwoodworking.com/get-more/table-tops-and-wood-movement


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## wormil

> I know this is an old thread but this link might help with understanding the alternating growth rings in glueing up a table top.
> 
> https://www.canadianwoodworking.com/get-more/table-tops-and-wood-movement
> 
> - DDWW


If that's the one where they recommend the wives tale about alternating grain, ignore it, it's pointless advice. Tabletops don't warp because of grain direction and they don't not warp because of grain direction. Also a washboard table would be difficult to fix whereas a single warp is easy to fix.


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