MCQ - Yet another new pressure treated wood

[Marty Walsh]

Ok, so I've gotten sort of used to the corrosive nature, heavy weight, wetness, tendancy to warp and cup as it dries, and requirement to use hot dipped hardware of ACQ pressure treated lumber. From what I've read, CCA was pretty nasty stuff, and ACQ is at least a little more environmentally (and people) friendy. But, now they have to go and introduce a totally new type of pressure treated wood....?

MCQ, a new day in pressure treated wood!

Here's a link to information on it: http://www.greatsouthernwood.com/products/product.aspx?id=17
(hopefully not against TOS...:rolleyes: )

ACQ is Alkaline Copper Quaternary, whereas MCQ is Micronized Copper Quaternary. "So what" I said as I placed my order for the materials for the front porch of my shop this morning. I'm not a chemist, and have no idea what that means. "Can it be used outside for decking? Sure, same as ACQ. Kewl, send it over."

(Shameless plug for my shop thread...in case you've somehow missed it, have a peek here (http://www.sawmillcreek.org/showthread.php?t=36894))

They said that it's a little lighter in color, which to me wasn't a bad thing, since I'm not all that fond of that puke green color, and any time I've used it I can't wait for it to cure a little so I can stain it. Well, have a look at this:

44066 44067

It's not trick photography or anything. Those 2x10's are "normal AQC" lumber. Everything else in the pile is MCQ. I almost flipped when the truck arrived, not knowing whether I should refuse the delivery or be happy since I might actually be able to stain this stuff and get satisfacory results. (Although, I'm not really thrilled that the 2x10's don't match the rest of the load.)

I have to say, the MCQ stuff is * H E A V Y * with a Capital H!!!! Aside from that, I know nothing about this stuff. Has anyone had any first hand experience with it? (Kelly, you readin this...? ;) )

I'm not sure if I should go ahead and use it, and see how it acts and holds up, or go with something I'm not thrilled with, but have at least grown accustomed to dealing with.

Thanks in advance...
- Marty -

[Marty Walsh]

Wow, plenty of views, but no responses. I'll take that as a NO to anyone here having any experience with this stuff. I'm going ahead with the plan to use it and will report back on my experience if anyone's interested.

Thanks...
- Marty -

[Jim Becker]

First I've heard of it, Marty...

[Andy Hoyt]

Marty - that looks and sounds an awful lot like the stuff that gets used quite heavily in California for many years. Sadly I do not recall the alphabet soup name it went by.

[Marty Walsh]

Thanks Jim.

Andy, according to the manufacturer's website, this is a brandy new treatment. And from the lack of responses here, I suspect it might be new.

Aside from the ridiculous weight, it holds promise. I guess I'm a guinea pig and will be finding out...:o

Thanks...
- Marty -

[Kelly C. Hanna]

Hey Marty. We just got in from Canton and I am reading this with excitement!! I hate to hear that it is heavy, but the color is fantastic. I have not seen any of this in our area, but will be asking tomorrow.

I hate ACQ lumber. We've had to stop using the 2x6's for decking....it's just too unstable after drying. We have gone to the 5/4 size and found it to be more stable [and lighter]. :D

I would definitely try it. I fear that ACQ is on the chopping block since it's so unstable.

Please keep me posted on how it dries out and the stability factor. Also was it more expensive? Did you like working with it?

[Marty Walsh]

Hey Marty. We just got in from Canton and I am reading this with excitement!! I hate to hear that it is heavy, but the color is fantastic. I have not seen any of this in our area, but will be asking tomorrow.

I hate ACQ lumber. We've had to stop using the 2x6's for decking....it's just too unstable after drying. We have gone to the 5/4 size and found it to be more stable [and lighter]. :D

I would definitely try it. I fear that ACQ is on the chopping block since it's so unstable.

Please keep me posted on how it dries out and the stability factor. Also was it more expensive? Did you like working with it?

Kelly,

I've been hoping you'd find this thread and respond...;)

I'm not surprised that this stuff has hit the market here before other places. There are several processing plants within a 30-45 minute drive from here. In fact, it wouldn't be impossible for some of this lumber to have been made from pine trees from my own property when I had the stands thinned a few months ago! Truckloads of pine logs are so common around here, I no longer even notice them most of the time!

Now on to the material...

First off, the price is the exactly the same.

I have to agree that the color is certainly promising, especially for stainability. And if you visited that link I supplied, you'll see that it actually comes factory stained in a few wood 'flavors'. My supplier wasn't even aware of these other flavors, so he couldn't help me with pricing them, but this claim has me interested:

"Outdoor exposure testing has shown that YellaWood® brand products with MCQ preservatives treated with color pigments will retain their colors longer than true redwood and cedar products. "

Workability is a whole different ball game. I've mentioned that it's ridiculously heavy. And I mean that! I posted a shot today in my shop thread of the 6x6 posts I raised. A total of about 16' of 6x6, and I swear it weighed WELLl over 200 pounds!!! To give you another example, I tried to use a pair of Quickclamps to hold the 16' 2x10 ledger on the shop. Nope, too heavy... the Quickclamps failed and it crashed to the ground! I would have had no problem with the same ledger in ACQ.

You know how ACQ is pretty rough on blades and bits. Well, be prepared for ACQ's tougher sibling!!! I had my skill saw bind more than a few times cutting those 6x6's today. And I had some serious smoke coming from a 3/8" spade bit while I was pre-drilling for lags!

My most important concern/question about MCQ is, like you, it's stability. I learned the hard way on my spa deck that ACQ 2x6's are too unstable for decking. What started out as a PERFECTLY flat deck, with EXACT 1/8" spacing between boards, has morphed into a kiddie roller coaster with gaps ranging from 1/8" to over 3/8"!! :mad:

I'll be finding out about MCQ's stability soon enough though, since I decided to risk it and go with 2x6's for the decking. I might be posting here in a few months lamenting that choice...time will tell. I just couldn't justify the additional price of the 5/4 decking. It's almost 50% higher than 2x6's!!! Wait a minute, you're telling me I'd pay 50% more for less wood?

Well, I'll keep you informed as time tests this stuff. And please do the same if you have a chance to try some out when it hits your market.

Thanks...
- Marty -

[Cliff Rohrabacher]

I liked the old PT. It worked.

[Chuck Trisdale]

I used pressure treated 6x6's from Yellawood about a year ago on a fence I was building. I assume it was ACQ? About 4 out of 16 posts warped so bad when it cured about 6 months that they are way out of line now. One is a massive 6 inches off at the top... 6 inches :mad: It is so bad i ought to take a picture to show you. It was a corner post and ran away from one side of the corner.

I couldnt have made it bow that much if I was trying to. I hope this stuff does better.

[Frank Pellow]

It is interesting to learn of all the problems folks appear to be having with ACQ pressure treated wood. Over the last few years, I have used ACQ of just about all available dimensions on many diverse projects and have have very little warping, shrinkage, or cracking. Also, the wood has taken many different stains that appear to be holding up well.

My guess is that I have been fortunate because of the wood that is being treated. In my case, the underlying wood is almost always Ontario or Quebec spruce (and, I think, mostly white spruce).

What types of wood are you using that are causing these problems?

[Steve Clardy]

Whether you are using the old or new treated posts, which most of our treated posts in the US are pine of some flavor, is to understand that no matter the treatment, some is going to warp, split no matter what.

Most of the reason it does is, that in order to pressure treat, the lumber has to be GREEN off the sawmill. No drying.
All pressure treated lumber is green lumber.
It has to be so the treatment chemicals will penetrate the lumber.

[Jim O'Dell]

Marty, does the new MCQ require special nails and screws like the ACQ dows? Just curious. Jim.

[Marty Walsh]

Whether you are using the old or new treated posts, which most of our treated posts in the US are pine of some flavor, is to understand that no matter the treatment, some is going to warp, split no matter what.

Most of the reason it does is, that in order to pressure treat, the lumber has to be GREEN off the sawmill. No drying.
All pressure treated lumber is green lumber.
It has to be so the treatment chemicals will penetrate the lumber.

Steve,

You're right that this is ALL pine, Southern Yellow to be exact. And you're right that it's green when it's processed. But even so, it shouldn't warp, cup and twist as bad as it does.

Oh well, I'll see if this new stuff is any better...I'll report in a few months...or sooner if it does anthing nasty sooner.

- Marty -

[Marty Walsh]

Marty, does the new MCQ require special nails and screws like the ACQ dows? Just curious. Jim.

Jim,

The manufacturer is suspiciously ambiguous about fastener requirements:

"There may be additional products (other than stainless steel or hot-dip galvanized) that are suitable for use with YellaWood® brand products treated with MCQ preservatives. Please consult with the individual fastener or hardware manufacturer for recommendations for use of their products with Micronized Copper Quaternary treated wood. "

I didn't take any chances, so I'm using the same hot dipped stuff I always used with ACQ. One thing I did have to do was return a roll of flashing this morning. My supplier wasn't aware of that MCQ can't come in contact with Aluminum, so that's what they sent me. I had to exchange it for a roll of Galvanized.

- Marty -

[Marty Walsh]

I used pressure treated 6x6's from Yellawood about a year ago on a fence I was building. I assume it was ACQ? About 4 out of 16 posts warped so bad when it cured about 6 months that they are way out of line now. One is a massive 6 inches off at the top... 6 inches :mad: It is so bad i ought to take a picture to show you. It was a corner post and ran away from one side of the corner.

I couldnt have made it bow that much if I was trying to. I hope this stuff does better.

Chuck,

Anyone that has ever used ACQ can probably relate to your problem...and probably has problems of their own they can exchange. I know I do! :mad:

I sure hope the posts I set over the weekend don't twist and warp, since they're the support posts for my new shops porch! I might be a little better off than you though, since my posts will be tied with rafters into the bottom chords of the roof trusses. That might keep them straight...at least I hope so!

- Marty -

[Frank Pellow]

Chuck,

Anyone that has ever used ACQ can probably relate to your problem...and probably has problems of their own they can exchange. I know I do! :mad:

...

- Marty -
Not everyone. :) See post #10 in this thread.

[Marty Walsh]

Not everyone. :) See post #10 in this thread.

Frank,

Of course you're right. What I should have said was everyone that's used 'SYP ACQ" has had similar problems. You having access to ACQ Spruce changes the equation completely. You lucky dog...:o

- Marty -

[Kelly C. Hanna]

I will Marty. Sounds like it's going to be a heavy workload totin' that stuff around. I'd be happy to use it for decking but not if the 5/4 stuff is twice the price. Here 5/4 decking is $2 cheaper than 2x6's [12' boards].

We'll be the last to get it. That's said, it's cool cause we'll hear all about it first. Heavy is okey, just hope it's more stable.

On fasteners, the copper in the treatment is what eats up the other metals. While I have used regular nails in ACQ [before the new nails came out] and had no problems, I use Hot Dipped Galvanized nails and coated screws as well.

SYP PT does funky stuff when used for decking. Ironically, it's been less stable in the last several months than it was before.

Unless they are hidden I have also stopped using PT posts for deck railings and pergolas. All eight of my pergola posts here at home had violent bending and twisting episodes after the pergolas were built. I am going to have to face all either of them with Cedar 1x8's to disguise them. I ahve gone to either Doug Fir or Cedar posts.

As for deck railings, I am pretty much done with PT anything...cedar or cypress only from now on. I just cannot stand to go back to a job and redo something.

[Marty Walsh]

Well, I've been working with this MCQ stuff for a few days now...and I HATE IT! Aside from being way heavier than the already heavy ACQ, and being harder on tooling than ACQ, there are dimenstional issues. All the 2x6's I'm using for the decking on my shops front porch came from the same unit. One would except (hope) that they'd all be pretty close to the same size. Well, the only dimension that's the same is the length. They're all 16 footers, and they all measure 16' 1 1/4".

The problem I'm having is that they differ by as much as a quarter of an inch in width, and by as much as an eighth of an inch in thickness!! Imagine the challenge that's been posing in the construction of a nice level smooth deck! Even using my BoWrench, I'm REALLY struggling to get rid of the gaps between the boards. I have been successful for the most part:

44640

There are going to be a few out-of-the way places where I simply couldn't get rid of the gaps, but that's because I couldn't find a board of matching size to the previous board.

I'll post after a while and shoot that same shot so yall can see what sort of shrinkage I'm getting.

Oh, and while I was screwing down the decking, I happened to read the stamp on one of the boards. I'm not sure what all the rest means, but doesn't this mean that the boards I'm using are KILN DRIED?

44641

As Steve posted above, (and I agreed), I was under the impression that all the treated lumber was treated while green. But then seeing this stamp, I'm pretty sure the KD means it's been kiln dried. Is it possible that it's dried AFTER being treated? I can't imagine that to be the case, given how SOPPING WET this stuff is!!

Oh well...I'll update this thread again once the decking starts its inevitable shrinkage.

- Marty -

[Steve Clardy]

Marty. Does that say KD-19 ??

[Marty Walsh]

Marty. Does that say KD-19 ??

That's how I read it Steve. Know what that means?

[Marty Walsh]

That's how I read it Steve. Know what that means?

Found it:


Moisture is a factor in almost all types of treatments. It’s especially problematic when Southern Pine lumber is treated with the waterborne preservative CCA. Fortunately, the Southern Pine grading rules require that lumber 2 inches or less in thickness must be dry before it can be grade marked. The grade mark shows the moisture condition at time of grading, which is generally KD19 (kiln dried to 19% or less moisture content). It may be difficult or even impossible to find wet pieces scattered throughout a package of 2-inch lumber stacked high up on a truck at the gate of your treating plant, so look for the KD19 on the grade mark. It’s generally reliable because the ALSC grade-marking program has stringent moisture requirements.

I still don't understand how this stuff can be so obviously SOAKING WET and yet be kiln dried!

- Marty -

[Andy Hoyt]

It means that it has been dried to 19%. Which is the standard according to this place - http://www.southernpine.com/mold.shtml

Got a meter?

[Marty Walsh]

It means that it has been dried to 19%. Which is the standard according to this place - http://www.southernpine.com/mold.shtml

Got a meter?

Andy,

I don't have a meter, but a piece of paper towel would tell me it's wet!! :eek:

- Marty -

[Steve Clardy]

Yep. They must be drying it down to 19 now, then treating it.

Guess they've up'ed their pressure tanks.

Ever see one of those tanks?
Built like a tank.

Guess with this new stuff, they can treat drier timber now. I'll have to read up on it

[Kelly C. Hanna]

I think they have always dried the lumber before treating, but don't quote me on that one.

Sorry to hear it is such a pita to work with. I know regular green PT is also greatly varying in size and thickness...drives me nuts when decking with the crap. That's one reason we have gone to 5/4 exclusively on top...it's consistent in thickness.

ACQ only takes a week in the sun to shrink drastically...let's hope MCQ is more stable and doesn't shrink wildly.

Lumber prices [PT] fell $2 per board on Thursday here in the south. This can only mean MCQ is on the way. I really am happy that you are testing it for us! Hope it acts right and makes you proud of your deck.

[Steve Clardy]

Kelly. There is a treatment plant north of us, two hour drive.

All there pine comes in on a rail car, directly from the mills, green.
I talked with the manager several years ago, toured the plant.

Now this was on the old treatment. He told me it could not be dried, or it would not take the treament clear to the center of the lumber.

[Bill Moser]

Any PT lumber I've worked with has been soaking wet from the yard,
which has meant major shrinkage as it dries...

[Devanice Oliveira]

I would like to understand the market of wood preservative in the U.S. mainly ACQ and MCQ. Do you know, where I can find information about that products? MCQ can be used in all applications in which ACQ is used? Like above ground, in contact with ground, etc.

What is the difference about MCQ and ACQ? I heard that MCQ does not contain ethanolamine (MEA). Do you know, if it is true?

Do you know, how many liters of wood preservative is consumed in the U.S.? And, how many liters of MCQ was consumed in last season?

Many thanks,

Ms. Oliveira

[Jim Becker]

Ms. Oliveira, I doubt that SMC members are all that familiar with the details you are asking about given that most are "consumers" rather than manufacturers. You may have better luck with industry sources.

[Brian Sutton]

I just found this board and this thread...a few things that I can contribute....

I have dealt with "treated" lumber for years (since the days of penta and creosote) being in postframe construction.

In regards to the weight and drying....KD19 is correct for untreated lumber, however you should search for a source of treated lumber that will supply you with KDAT19 (Kiln Dried After Treatment). If the lumber is KDAT it will be stamped on the lumber, as required by industry standards. Not all (actually very few) lumber yards carry this, especially the big box stores. It costs more to dry the lumber a second time, and they pride themselves on selling cheap, not quality. If you get your treated lumber with a KDAT19 stamp, it will be lighter and you will minimize shrinkage after installation.

All lumber that is to be treated is kiln dried before treatment. It is then treated and (should be) dried again. The treatment process is shown in the animated gif that I zipped and attached.

As to fasteners, they say any fastener that has a G90 treatment is acceptable. Their statement that "others may be acceptable", defers the decision as to whether it is usable to the nail manufacturer. They do also say that it 25% less corrosive than CCA, while ACQ is far more corrosive than CCA.

As to containing MEA, it does.

Strange that it posted this in this position as I hit the "Post Reply" button after Jim Becker's Mar 14th post....

[Mike Running]

Most but not all treating plants try to get the moisture content down to around 25% before treating with CCA, ACQ, CA-B and MCQ. Plants with higher pressure pumps can treat S-GRN lumber.

The amount of chemical is realatively low (2-6%) compared to the water carrier.

To properly treat the lumber they have to get .6" penetration or 90% of the sapwood so unless the lumber is kiln dried after treatment it is going to be very heavy.

Within a year there are going to be some new treatments available that don't rely on copper. They will be more enviromentally friendly and less corrosive so the requirement for Z-max, S/S or heavily hot dipped galvanized fasteners won't be required. These new treatments are going through the recognition process with the American Wood Preservers Association now.