# Help With Treated Wood Table



## BrandonR (Feb 14, 2012)

Hello All-

I just got an a custom order from a client… They want me to build a harvest table style,

http://4.bp.blogspot.com/_vDMlZQUYRTI/SGegiiYswcI/AAAAAAAAARs/TVFD9-0tALw/s1600-h/deck_table.jpg

I am excited to build it… My big concern is using pressure treated wood on the top… I plan to use pocket holes for all the joinery, with a skirt and 4×4 as the legs.

If I use pocket hole joinery to face joint the top pieces…. With the treated wood as it dries out have room to move? In other words will it crack if met flush together?

any advice on how you would tackle building it would be greatly appreciated. It will all be with treated pine.

Thanks!

Brandon


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## mnguy (Feb 4, 2009)

First, let your lumber air dry for several days - week before you begin milling. Treated wood is sooo wet, it will really move if you mill it wet. It will even tend to rust your tools. I would also rough mill and then let it dry again for a few days before final milling.

Your example photo appears to show boards that a) have a relief or small gap between them, and b) are breadboarded. I would not firmly lock the boards together with pocket screws or other firm fastening methods, but leave a small gap between the boards for drainage. Bread boarding the ends will help keep cupping under control. Glue / screw the boards on the two edges to the breadboard ends, and then put one screw / a spot of glue in the middle of the end each field board to hold it to the breadboard ends but still let it expand and contract. I'm not sure how much of a gap you should leave between the boards, but if you measure one of the boards for the top before you let it air dry and then measure it after, you'll get some idea of the max width it will have in the assembled table.


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## Cosmicsniper (Oct 2, 2009)

Why are you using pressure treated wood?


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## donwilwol (May 16, 2011)

I's use cedar. You're going to have a tough time keeping PT from moving, and do you really want to eat off PT?


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## Cosmicsniper (Oct 2, 2009)

Pressure treated wood is best used where you might get insect decay due to excess moisture, meaning its typically used where there is contact with the ground. I see no virtue in using it for the top of a picnic table, particularly since I wouldn't want to be eating off it. I know PT wood is cheap, but there are good woods for outdoor use that will withstand the test of time. Don mentioned Cedar. I like white oak. Others like teak. But even if you use good ol' fashioned pine or fir, you can give it a good finish to help it last longer.


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## Charlie5791 (Feb 21, 2012)

Pressure treated wood is safe for a picnic table as long as food is never prepared on it. HOWEVER….. and it's a BIG "however"... pressure treated wood is invariably VERY wet when you get it and it takes a long time to dry through. If you get it and and build with it when it's not dry, it WILL crack and split and move like crazy.

Do NOT use pocket hole screws to securely face join the top pieces. My opinion is that you're asking for trouble. The suggestions for cedar and teak are nice, but if you're in an area like mine, .... it's actually cheaper for me to go to Canada and buy cedar and bring it back than it is to buy it locally… and that's if I can find it anywhere at anything resembling a reasonable price. And teak…. well… forget it.

Over the years I've had better luck using ANY decent wood I can find…. kiln dried or very well air dried… applying a penetrating oil and a marine type finish. Those items seem to outlast pressure treated, not because the pressure treated stuff rots, but that it basically tears itself apart.

Just my 2 cents…. probably worth every penny.


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## BrandonR (Feb 14, 2012)

Thanks for all the great advice. I planned on using pressure treated because it is an outdoor project. I know cedar is ideal but in my area is 3 x as much…. Not an option for this piece and budget…

My options are basically pine or treated pine…. I guess it sounds like I should make it out of pine and then have my client seal or stain it right away….

I would love to use teak as well, but can't imagine the price…

It looks like I will just use pine, and have my client apply a finish to it right away.


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## chrisstef (Mar 3, 2010)

Could you possibly use cypress instead of pine? It works about the same and should be relatively close in cost if you can get it in your area.


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## bbc557ci (Sep 20, 2012)

If you call around to lumber yards (not the Home Depot and Lowe's types) you might be able to locate some kiln dried PT.


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## BillWhite (Jul 23, 2007)

Kiln dried PT lumber is an unknown entity in my area.
I wouldn't touch that job without soooooo many caveats that the potential customer might wanna rethink the material of choice.
Just my opin .unless they are just finiky
Sealing "right away" is an effort in futility. That stuff is soooo wet with chems and other crap that the project will fail.
Not "if", it is " when" it will fail.
Might wanna consider an exterior grade of mdf such as EXTERA unless they are just set on a wood specie.
Don't get yourself in a "you built it and it fell apart" situation.
My dad built a picnic table from a Masonite product called "die stock". This was many years ago, so the names might have changed, but it sure looked like today's exterior grade mdf.
The table was solid after many years in the South Mississippi sun and humidity.
Bill

Bill


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## donwilwol (May 16, 2011)

Isn't kiln dries PT dried before treating, so its still wet when you get it?


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## Hammerthumb (Dec 28, 2012)

I believe Don is correct. The kiln dried PT lumber is treated after drying. It would still be wet. I would not use PT lumber for this project. Too many toxins and chemicals that are hazardous to the end users health. You might also think about using one of the simulated wood products produced for wood decks. Would last forever. Don't know about the price though.


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## treaterryan (Feb 20, 2012)

Lumber is kiln dried and then treated as Don said. The treatment process adds a small amount of water as, depending on the preservative, water is generally the carrier for the active ingredient. Usually, PT lumber comes in around 18% after treatment. So you coukd dry it for a few weeks in your shop before cutting. All PT consumer grade lumber is kiln dried.

Pressure treated is NOT okay to eat off of. I know, you eat off of plates, but what keeps a kid from eating his gummy bears off of the table top?

Generally you have to use special grade fasteners for PT as the preservative is highly corrosive.

Stick with pine or doug fir to match their deck.


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## BrandonR (Feb 14, 2012)

Thanks for all the posts.

My client is deciding with going with regular pine and staining and sealing it right away, or splurging on the cedar…

If I am going to use a stable wood, would it be ok to screw the top together using pocket holes? Or would you still recommend not going with this method?

Furniture construction is very new to me. So trying to figure the best way to tackle this!


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## redSLED (Mar 21, 2013)

Outdoor table = big temperature and moisture ranges! No matter what your do with your pine, it will move, expand, contract and knots will pop. Unless you have barn-stored straight 100-yr old heart pine or something similar. Cedar is highly recommended or hardwoods mentioned by others above. And yes, you can pocket hole the boards, or biscuit them together and pocket hole them - BUT THEN YOUR TABLE TOP MUST BE A "FLOATING" HELD-DOWN TABLE TOP - not screwed down/fixed to an apron/skirt or cross members underneath because if so your boards may incur grain cracks (across-the-grain shrinkage) and/or buckling/cupping (across-the-grain expansion) within 6 months easily.


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## BrandonR (Feb 14, 2012)

redSled- Thanks for the information. I am defiantly doing the build with cedar now, just got confirmation from client. Do I still need to be worried about how I attach the top to the skirt and base? Or was this just for pine or treated?

Thanks!


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## donwilwol (May 16, 2011)

if you're making a solid top ( boards attacked together) you'll need to plan for movement, no matter what kind of wood it is.


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## redSLED (Mar 21, 2013)

^ Yep. Thread on this at: http://lumberjocks.com/topics/38368

The pic below shows the fastening setup for a indoor table top that will typically shrink a bit after being made.

However, since you are making an OUTDOOR table top (boards attached to one another), you need to account for regular cycles of shrinkage and expansion (mostly across the grain). There are no exact rules on how you should do this - possibly others here can chime in here on their custom designs. This is why most outdoor solid wood table tops you see are not made with boards attached together - easier (cheaper!) to build plus customers won't be trying to return their cracked/cupped topped-table for their money back. You will need to address your design (and cost estimate) w.r.t. these considerations with your customer - seller beware! I look forward to your build table photos.

PS: I wish someone explained all this to me 15 years ago, haha.


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## BrandonR (Feb 14, 2012)

Thanks for all the great advice. This has been quite a learning experience for me, very nerve racking as I start to get more people interested in me building for them.

I have readjusted the design for the client… I am not going to use all cedar. The table top will still be the same look, but now I am going to leave a 1/2 gap between all of the boards that are running parallel on the top. I will attach them to the bread board ends, but not to one another.

That should give the wood some room to move a bit across the grain.

redsled-that is a great technique you shared, I would have never thought of that or came across it!


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## kizerpea (Dec 2, 2011)

take a look at the trestle table built by roy underhill…the woodwright shop…


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## redSLED (Mar 21, 2013)

Oh boy, you mentioned bread board ends. Be warned - you better check some threads on that before you build. Seriously.


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## redSLED (Mar 21, 2013)

A quick read on bread board ends (among many) for you: http://lumberjocks.com/topics/48712


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## Granddaddy1 (May 16, 2012)

What you're looking for is KDAT treated lumber (kiln dried after treating). This material is available from suppliers of specialty treated materials and is ALWAYS stored indoors. The material has to be kiln dried BEFORE treating, to open up the cell structure of the wood and allow space for the chemical, then it's kiln dried to 19% MC again after treating. This material is usually available in higher grades only-#2, #!, Select Struc, Dense Select Struc, etc. Good luck with it!


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## BrandonR (Feb 14, 2012)

Thanks again everyone for all the advise. I ended up using cedar for the project. Glad I did, and will encourage future clients to go with cedar. Realized pretty nerve wracking bidding a custom job… i think I underbid this one a bit, but really enjoyed making it. It adds to what I can do and learned a lot.

I spaced the top boards about 1/4 of an inch… I think this will give it room to breathe a bit. The top is attached loosely to the base. Only time will tell how it holds up…

Here is post…

http://lumberjocks.com/projects/82932

Thanks


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## MrRon (Jul 9, 2009)

You might consider making the top out of the wood/plastic planks that are used for decks.


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