Treated Lumber vs Teak

[swordds]

About four years ago I made a cockpit sole grate out of 1” X 2” treated lumber and deck screws from Home Depot. The treated lumber has nicely rounded edges. Originally it had a greenish tint but that as weathered to a sun bleached grey very similar to my unfinished teak. The whole project took only about 3 hrs and probably cost less than $30. In 4 years it has never been varnished or oiled and it gets plenty of exposure to salt water, rain water, and the hot Louisiana sun and there are no signs of rot or rust. My point is - perhaps there are other uses for treated lumber and deck nails as much cheaper and more sustainable and available alternatives to teak?

[Attikos]

There's a naval architect, specializing in small boats, located in Bayboro, North Carolina. His name is Graham Byrne, and he designed the popular "Spindrift."

I needed a tender, so bought a kit from him last year. He's a mighty nice fellow, open, friendly and helpful as can be. In the conversations I asked about material for the gunwale. He said some like to use teak or another exotic wood, and that it works well, but that his own preference is for treated pine from the building supply store. It lasts better, works more easily, and is a whole lot cheaper.

He knows what he's talking about. I took him at his word.

[Cheechako]

I made a cockpit grate out of Western Red Cedar for one boat. it worked out fine and is super lightweight. None of that poison to walk on with your bare feet either. I additionally treated it with oil stain and it looked a lot like teak. No need for that though. We have fence posts in the wet PNW ground up here from Western Red cedar that have been there since I was a kid 60 years ago!
Treated lumber will rot, my home deck is proof! But for the $ no big deal. Glad it worked out for you.

[Attikos]

They've got the arsenic out of it. Treated lumber now isn't nearly as bad as it was twenty years ago.

That said, I used cypress for grating and seat slats on my cruiser. I wish you could still get chestnut. There are split rail fences on my family's farm made from that two hundred years ago.

[travis_farmer]

As i am in the home-building field, i have used the new treated lumber, and have seen it corrode fasteners, fast.


~Travis

[chris mac]

Originally Posted by travis_farmer

As i am in the home-building field, i have used the new treated lumber, and have seen it corrode fasteners, fast.


~Travis

Here in Canada, treated wood was changed around 10 years ago give or take. It changed from the arsenic base to a chromium copper base.(at least that's what my lumber supplier states)
During the first few years nails and screws were dissolving, lifespan of about 5 years. Any pressure treated posts that I cladded with aluminum ate through it in about 6 months.
After a few years the problems went away. I assume they altered the formula.
I prefer to not use any pressure treated if I can avoid it. On a boat/salt water environment, I wonder if a galvanic reaction can take place?

[scotty c-m]

I've goten splinters from treated wood. They can get really nasty.

[dannc]

There are a variety of chemicals in treated wood. In the US, ACQ mostly replaced CCA a decade or so ago. The problem with ACQ is that it will eat up normal fasteners so you need to use what is specified to work with ACQ. MCA treated wood is supposed to have metal corrosion rates like CCA.

Irregardless of the treatment, CCA, MCA, or ACQ, how much chemical is put into the wood determines its usage. Some treatment is for ground contact while others are for above ground. There are treatments for wood piling in water as well. There should be a tag on the board that specifies its usage per its treatment.

Using above ground PT wood in the ground, or in contact with the ground, is not likely to end well.

The box stores do not always have a good selection of pressure treated woods. If I need a bunch of PT wood for a project I go to a local company since they have better quality, price and selection.

Later,
Dan

[Hardhead]

I believe pier builders now indicate that stainless steel screws are required for pressure treated. Easy enough to do-

[swordds]

Well, I am almost sorry I even mentioned it. But just to note, the deck screws I used are holding up just fine and it states “Treated Lumber Approved” on the Box.

[Captain Bucknut]

Treated lumber eventually grinds itself to to the point where it rots or disintegrates.

[dasreboot]

I was thinking of using thermally treated lumber specifically cambia wood ash. its sold by northwest forest products. looks reasonable in price, and is supposed to increase rot and insect resistance.

[nhschneider]

It's been my experience that pressure-treated lumber's primary application is for places where timber comes in contact with the ground as its resistance to rot and insects is high.

At the yacht club that I used to belong to, they replaced the club house deck with pressure-treated lumber that splintered badly within a few months. The docks where my daughter keeps her boat were also made with pressure-treated lumber and even though they're not very old, they're in terrible shape. On the other hand, the teak grate in the cockpit on my boat is almost 35 years old and is still in excellent condition.

Fair winds and calm seas.

[thruska]

Very few decks are are laid with treated wood recently. Most I believe are the synthetic compositions. I have acquired some drop from a deck job on a motel/condo, with the intention of using it on swim/boarding platform . (The redwood rotted) I called West Systems to find out if this stuff can be joined with epoxy before I salvaged some.
West Systems has a published procedure to do just that. And its quite simple.
The material is not at all slippery. Different colors available. Different brands. Different quality.
Fwiw

[Fence Man]

As Dan already mentioned, the varying retention of chemical treatments have a broad range of resulting success and failure. I have had the pleasure of spending several months of my life in the fight against shoddy wood treaters, with a mild degree of success. All treated wood is not created equal, and careful attention should be paid when working with it. Poorly treated pine is generally very easy to spot once you cut into it. If it's white, it didn't retain any treatment chemical. The mistake that is generally made in the treatment process, is the rush to turn over product trumps quality. Southern Yellow Pine, for example, needs to be around 18% moisture for optimal penetration and retention. Too wet, and the cells are still full of water. Too dry, and the cells become hardened. The pressure treatment process starts with pulling a vacuum to compress the individual cells of the fat lightered wood. Once compressed, the treatment chemicals are flooded in under pressure, and the resulting expansion of the compressed cells soaks up the treatment chemical....Just like a sponge. Failure to properly dry the timber will always result in low retention rates and minimal penetration. I have had several "certified" fence posts come back from an independent lab with less than 1" of penetration and less than .20 lbs/cu ft of retention.....When full penetration and retention of a minimum .40 lbs/cu ft were supposed to be guaranteed. These problems are easy to see, but lab results are the only ones that hold up in a court of law. The simplest it was ever explained to me was by an old Kentucky wood treater, that has been doing it right for 50 years. He told me that "It takes a gigantic pile of money to be in the fence post business and do it right". Millions of dollars in raw posts that have to air dry for 9-10 months before any return can be realized. It's easy to see why most of them cheat.
That's my rant on treated wood. We have mostly switched to SS40 ironwood posts with class III galvanize coating, and haven't seen any bugs, splits, warps, or rot since. In the 15 years prior to that switch, I replaced enough wood posts to buy a new Lagoon 450, and that thought makes me angry. lol I also keep a current copy of the American Wood Preservers Association book of standards, if any of you would like a bit of light reading.

And please, no exposed CCA on the boat. The stuff is no good for you. ACQ doesn't have near the bug fighting capability of CCA, despite what the label may say.