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HEMLOCK, TAMARAC, VS PRESSURE TREATED

mapleheart's picture

Hi everyone.


I am building a new deck on my house this spring and I want to get some opinions on the use of Tamarack and hemlock, I know most people in my area use p/t lumber but I want to avoid it if I can. So if you know the pros and cons l would appreciate it.


Shaun


MapleHeart Lumber

(post #60486, reply #1 of 28)

You talking framing or decking and rails?


What part of the country?


Shaded or sun?

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(post #60486, reply #2 of 28)

I am in central Ontario Canada.


The deck will have lots of sun in the summer and I was going to use Hemlock for my posts and Tamarac for the decking and rails.

(post #60486, reply #3 of 28)

and PT for the framing?

 

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(post #60486, reply #4 of 28)

I am trying not to use any p/t. What I want to know is can I get away with it or do I have to use p/t if I want it to last.


Has anyone used Tamarac or hemlock for a deck and if so how did it stand up to the weather and rot compared to p/t?

(post #60486, reply #5 of 28)

Forget the Hemlock, it will rot.


In the early 60's, was helping an uncle build a deck out over fresh water.  He had ordered DF for the posts (above water) and oak for the rails/decking. He looked at one 4x6 and started berating the yard, as they had sent him a piece of %4&^#^* hemlock instead of Dfir! Got a good education that day on color, grain, end grain, etc. on what was going to rot.  Hemlock will rot.

(post #60486, reply #6 of 28)

Whatever happened to the oak rails and deck?  I'd imagine the same as the hemlock.

(post #60486, reply #10 of 28)

I think you guys on the west coast are looking at a different species when you say hemlock than the tamarac we have here in the east. Your Doug Fir is king of the softwoods in lots of ways, reigning side by side with the cedars and redwoods. our "fir" is pretty crappy by comparison, so I guess it's a trade.

 

 <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

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We did the best we could...

(post #60486, reply #11 of 28)

They`re right about the splinters, big time. Also getting good Hemlock without shake can be difficult. On the plus side, It will wear well and the ants don`t like it as much as some other soft woods (if you keep it dry). Carpenter bees seem turned off to it also. It doesn`t have the pitch in it like the pines do. Did I mention the splinters? Never worked with Tamarack but I hear it`s very similar to Hemlock. Apparently Tamarack is one of the few, if not the only, evergreen that sheds it`s needles like the hardwoods do. Not sure what that has to do with anything but you might run up against that question in Trivial Pursuit sometime. Sid I mention the splinters?

(post #60486, reply #12 of 28)

Thanks for the feed back.


Just to clear up a point Hemlock and tamarac are two different species, Hemlock grows on our ridges in large stands and Tamarac is a eastern larch that grows in wet low areas and yes it will lose its needles in the fall, it is also knowing as the trappers tree as old folks tales say that when tamarack loses its needles fur pelts are at their prime.


My main concern for using them is how long they will last and what to expect for twisting warp, rot and of course splinters.


If I use hemlock for the posts and keep them above ground (I am on bedrock) and Tamarac for the decking and rails will it last? I know in the old days they used to line wells with tamarack and most of the barns in my area are built out of hemlock.


I am in the lumber business but I deal with mostly hardwoods and will admit to been a little dense on softwoods.


Thanks again


Shaun


MapleHeart


 

(post #60486, reply #13 of 28)

"Apparently Tamarack is one of the few, if not the only, evergreen that sheds it`s needles like the hardwoods do. Not sure what that has to do with anything but you might run up against that question in Trivial Pursuit sometime."


There's an evergreen species called "Larch" that grows on the Eastern slope of the Cascade Mountains in Washington (state) that might lose it's needles every year.  They turn from green to a shimmering gold around mid October, I'm pretty sure they fall off for the winter.


I think they have Larch in Northern Idaho and Montana, too, anybody know?  What about the needles, do they fall off? 


 


 

(post #60486, reply #14 of 28)

I think Mapleheart is correct, as are you (see above post). We have it here in PA in small quantities and although similar, Eastern and Western Larch (Tamarack) are slightly different. Again, only what I`ve read, never worked with Larch.

(post #60486, reply #15 of 28)

Yes the needles fall off in the winter.Larch is a very nice wood to work with,easy to


mill and has a grain like DF.Also nearly as strong as DF, would make a nice deck.


I`am from northen BC, does grow here a little, more to the south.


 


Pine is fine


Ed


 

(post #60486, reply #17 of 28)

TAMARACK LARCH

larix laricina

* also known as Eastern Larch, Hackmatack, Alaska Larch, America Larch, Black Larch, Tamarack

* 'laricina' is Latin for "larch-like"

* 'tamarack' is from the Algonquin word 'akemantak' which means "wood used for snowshoes"

UNIQUE FEATURES:

* like all larches, the Tamarack has deciduous foliage (needles) but drops them in the fall like leaves

LOCATION:

* grows mainly east of the Rockies

* there are a few isolated groups in the Nechako Valley

* can live on poorly drained soils - bogs and swamps - as well as on cool, moist, north-facing slopes

SIZE:

* this small, slender tree rarely exceeds 15 metres in height

CONES:

* seed cones: small, round, red at flowering, turning brown as they age

* stay closed on the tree

* pollen cones: yellow

NEEDLES:

* 3 sided

* blue-green and yellow in autumn

* grow in clusters of 15 to 25

BARK:

* red-brown, thin and scaly

WOOD CHARACTERISTICS:

* heavy, durable

USES:

* modern - pulp, posts, poles, fuel

* traditional - roots: sewing bark onto canoes; resin: relieve indigestion

An ex-boat builder treading water!

An ex-boat builder treading water!

(post #60486, reply #18 of 28)

Thanks for all the info.


I have decided to go a head with the deck using tamarck.


Now can someone give me the pros and cons of self supporting or attatching it to the house. The house is a sqaure Timber home if that makes a difference, also I am on bedrock and won't be able to dig holes for the supports.

(post #60486, reply #19 of 28)

that is the right decision. the hackmatack here has been used for boat keels and riubs with cedar planking or lapstrake for the skins. It sometimes got put in grouind for fence posts but locust was even better for that.

 

 <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #60486, reply #20 of 28)

I built a deck/dock a couple of years ago in N. Vermont, right on the shore of a lake.


I built it on a log crib made of cedar (eastern white, not western red) logs that I got out of the scrap pile at this local place that supplies the materials to build log cabins.  They were in the scrap pile because they were either too short, not straight enough, etc.  They were sawn three sides and the original tree round on the fourth side, tongue and groove top and bottom.  They locked together nicely, just like playing with lincoln logs.  The crib is filled with stones to try to resist movement from the ice. 


On top of the crib are some rough sawn hemlock 4x8 beams from a local sawmill, and on top of that were hemlock 2x8 joists every 16".  The deck was made from more eastern white cedar 5/4x6s.  I used aluminum flashing on top of the joists.


I didn't want to use PT for fear of the CCA leaching into the lake, plus you might get a nice dose of arsenic in your arse as you sit in your wet bathing suit on the deck. 


As far as longevity is concerned, assuming your Ontario climate is not all that different than Northern Vt, I think you should be OK without PT.  Have you considered cedar instead of Tamarack?  Very rot resistant, also doesn't seem to have much problem with splintering.  A dock we made from the cedar about 15 years ago does not show any signs of falling apart.  We'll see what happens with my cedar/hemlock creation as time goes on.  (See attached picture for new dock and portion of old dock.


good luck


Edited to say:


If you look in the picture, you can see that the four tree trunks just behind the dock are eastern white cedar, and the one tree trunk just visible way to the left above the canoe is a big ole hemlock.  Although not actually true, the dock could have been built from the surrounding trees.



Edited 3/24/2004 4:08 pm ET by AlecS


Edited 3/24/2004 4:50 pm ET by AlecS

(post #60486, reply #22 of 28)

Lucky Dog! No digging footings!

Get a good rotary hammer and some #5 rebar. (5/8") Bore some 3/4 holes now you can either epoxy the rebar in, or just use grout (portland cement and water.) Make yo'self a couple little forms , making sure you have atleast 4" of concrete, I'd go to 6". lay a small rebar grid in it too, tied to the stubs out of the rock. it aint goin NOWHERE!

(post #60486, reply #23 of 28)

It's typical in Ontario to epoxy rebar into bedrock, but I wouldn't say use a "good rotary hammer" -  I would say use a big-#### rock drill.


To the orginal poster: the hemlock question is one I've pondered.  Farmers still use it for fencing, etc., but what I've heard is that today's fast growing hemlock has little of the rot-resistance the old-growth trees had, meaning a barn built today won't last 100+ years.


Regards,


Tim Ruttan    

(post #60486, reply #24 of 28)

Tim,


  you can't paint all trees with the same brush..


     Look at the growth rings.. if they are tight and close together the decay resistance is the same as "old growth"  Use those in area's where the wood will get and stay wet.. use the wood with wider/fewer growth rings in dry areas..


 

(post #60486, reply #25 of 28)

I agree completely with what Piffin said above. Tamarack (I'll just add to the confusion by telling you that it's called juniper in Newfoundland) is highly rot resistant and very strong.  It bends well, not that that is likely to matter.  It might be inclined to split when nailing near the end of a board. Keep your drill handy.


Use the tar paper strips on top of the joists and make sure there is some air ciculation around them and they will last forever. The tar paper will make no difference to the board above. I think the paper just prevents water from getting into splits in the top of the joist caused by nailing deck boards.


Use a linseed oil stain or some other stain which tends to penetrate and seal the wood. Linseed oil, though it probably has no preservative properties will extend the life of wood outside simply because it prevents the intrusion of water on a cellular level. It's cheap and effective. Treat the butts thoroughly.


 


Ron

(post #60486, reply #27 of 28)

Ron,


    I need to confirm that we are speaking about the same wood.. I've seen a lot of wood called tamarack and the futher East  the further from what a true Tamarck is.


  Tamarck, (Larix laricina)  is a coneifer that sheds it's "needles" in the fall leaving the tree bare.. the wood is a sharp contrast between early and late wood.. early wood is creame color while the late wood is orange to dark orange..


  specific gravity is .53 to .49 modus of rupture 7,00 to 11,600

(post #60486, reply #28 of 28)

Larix larcina is what I am used to calling tamarack or, as I said, juniper.


It's an odd tree. It grows happily both in peat bogs and on mountain sides from Labrador south to New England and west to the Rockies and right north to the mouth of the MacKenzie. I've never seen one bigger than 20" or so at the butt.


My book says that the western larch, also called tamarack, is mostly found in SE British Columbia, in Canada and I don't know where in the USA. That's Larix occidentalis. It is a much bigger tree than the eastern tamarack. Properties of the wood are similar


Ron

(post #60486, reply #7 of 28)

I think you're going to get different opinions on whether PT is essential for longevity. Certainly the "subdeck" structure, the posts and framing, are the crucial components and are generally done in PT.


But depending on the site and how well the deck is designed, something like Hemlock could last a long time. I should defer to Piffin on this, since I'm sure he's seen a lot more older hemlock first hand than I have. But there are cases here in New England where hemlock has lasted many decades.


If you want to avoid PT--and I think there are lots of good reasons to do that--the key will be designing the structure such that it sheds water well and so that chronic dampness doesn't get a foothold. There are a lot of little tricks (actually, just good carpentry practices) that can help do that. Mounting the posts above grade on galvanized metal brackets embedded in concrete piers rather than directly in the ground, for example, or very thoroughly flashing the ledger.

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(post #60486, reply #8 of 28)

If using the hemlock for exposed framing you should consider the splinters that may appear over time if left exposed.  I used hemlock for framing one time and the splinters off of the stuff was a pain (literally)  The slivers are long and extremely sharp.  If left over time as you are talking about, may cause the splinters to rise...


On the upside the hemlock would probably make a beautiful deck and strong..


Where's Jon Arno ???........


First we get good- then we get fast !

First we get good- then we get fast !

(post #60486, reply #9 of 28)

It is my understanding that tamarac or hackmatack is merely a localized term for hemlock. But there are several different hemlock types so it might be a single subgroup. I've got a mental blockage on this right now though so I could be wrong.

Anyway, I have demoed for replacement seeral old decks ranging up to a hundred years old that had hemlock framing with CVG Fir or cedar for decking. They used a strip of 30# tarpaper about three or four incxhes wide over the joists before decking in. The problem with tthis method is that while the tarpaper is keeping water out of the joist, it is holding it against the back side of the deck piece. It is extremely easy to remove the deck boards that way, because they are so loose around the nails. Framing a hundred years, dceking every fifteen to twenty years

 

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Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #60486, reply #16 of 28)

Last November or December there was a discussion of this topic over on "Knots".  Jon Arno contributed to that thread.  You might want to check the archives under "larch".  Yes, as some of you have mentioned, I also believe that tamarac and larch are the same species and the focus of that thread was on tamarac/larch rather than hemlock.  If memory serves me correctly, Jon's conclusion was that, because of the high resin content, tamarac would be more decay resistant than many softwoods but not as decay resistant as redwood cedar, or properly prepared pressure treated material.  In this tread you can also find a photograph of a tamarac deck submitted by Scott Frankland.


Chip 

(post #60486, reply #21 of 28)

I used tamarck instead of pressure treated in my home.. the reason is no wood will ever last forever in the wrong application/installation..


   Thus it is an illusion that pressure treated wood is a real solution.. Consider it a bandaid at best.. Designand careful attention to the details  is far more important. 


    Since there is currantly so little experiance with pressure treated that doesn't have warnings attached to it,  I chose what should give me a durable alternative..

(post #60486, reply #26 of 28)

Hi, displaced Ontarian myself.  Used Hemlock, 4x4 or 4x6, I forget which, as stringers for our dock, they have held up excellently for over 5 years now.  Was told by 'oldtimer' at the time that a lot of the old wooden trestles were built out of Hemlock.  Used PT for the decking.

Let's not confuse the issue with facts!

Let's not confuse the issue with facts!