The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems

Chainsawr, The Worlds Largest Inventory of Chainsaw Parts

Smith Sawmill Service



Author Topic: "cheating" post and beam construction  (Read 30754 times)

0 Members and 1 Guest are viewing this topic.

Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
"cheating" post and beam construction
« on: May 23, 2009, 09:14:48 AM »
I've tried searching for this but not too much luck.  I'm looking at building a new post and beam sugar shack and a mill shed, not sure in what order yet.  I have no experience with post and beam construction but I have done lots of stick framing. 
They're both going to be very simple structures with just a single sloped roof, probably 9' high on the high side and down to about 6.5' on the low side and a width of about 10' and basically the sides would be open for now.  All the posts I am going to use rough 5.5X5.5 and probably the same for the beams across the top of the posts.  But on the mill shed I'll have a bigger beam over the 19' openeing, I just have to figure out how to cut a beam longer then the longest log my mill can cut, but that's another problem. 
Then for the rafters I was just thinking 2X6s seemed like the easiest (but if there was simpler way to do it with beams I'd be open to suggestions).
I was thinking of a concrete peir in a sonotube under each post with a metal bracket bolted to it to hold the 6X6.  The joints between the post and beams are what I was really wondering about, I was wondering if there are metal brakets available to make that joint instead of cutting a mortise and tenon?

Any advice at all on this project would be appreciated.

Thanks

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 7776
  • Age: 69
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • Share Post
    • jrsawmill.com
Re: "cheating" post and beam construction
« Reply #1 on: May 23, 2009, 01:45:14 PM »
First of all, welcome to this section of the forum.

Your design should be carefully understood and possibly reviewed to insure that the sizes of these timbers you want to use are large enough for the load they will be carrying.
From your profile I see that you're in Ontario. You'll need to know the snow load for your area to correctly size the beams for holding up the rafters. As well as correctly size the rafters.
Especially the mill shed roof.

Once that is done then you can size the joinery or brackets to hold the timbers in place.

Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #2 on: May 23, 2009, 02:01:58 PM »
Thanks Jim,
I've looked at the building code for sizing up the beams and rafters, a 2X6 on 24" centres is enough and I've sized up the beam for over the big opening and I'll either need double posts or make bigger posts but it will still be 6" wide, the beam will be 6x10 hemlock I believe.  I've looked at home depot and they don't seem to have an obvious bracket for what I'm trying to do, I assume I'm looking for a formed piece similar in construction to a joist hanger.  The only other thing I was thinking was a flat metal nailing plate on either side.

Offline Rooster

  • Senior Member
  • ****
  • Posts: 688
  • Location: Lake Mills, by way of Fort Atkinson, WI
  • Gender: Male
  • Tools are extensions of ourselves... share a tool.
    • Share Post
    • Photobucket image storage account
Re: "cheating" post and beam construction
« Reply #3 on: May 23, 2009, 03:50:27 PM »
Hey Night Raider,
There is a fastener system called Timberlinx that is used to help connect timbers, and posts to concrete. If you did an internet search you will probably find it.

Also, I don't own a mill but I know a few guys that do.  We have used a sliding deck system to mill logs longer than the mill can handle normally.  We have used LVLs (Laminated Veneer Lumber) (1 3/4"X 11") or larger. You can buy it in very  long lengths 30ft+.  Depending on the diameter of your log, you might use 1 or 2 LVLs side by side.  The LVLs are laid across the log supports on the mill like as if you were decking it.  The log is then placed on top of the LVL, and wedged so that it won't roll and the narrow end is shimmed and raised to max out your cut.  Taking a pass with the mill, ending close to the end of your mill rail stops, shutting down the blade, and then pushing the LVLs, log and saw carriage backwards, sliding across the deck supports, and then starting up the blade again and finishing the cut.  For instance, if your mill cuts 16ft, but you want to cut a log that is 20ft,.....cut into the log about 5ft, stop, push it all back so the carriage is back to the start point , then finish the remaining 15ft. 

Good luck!
Rooster
"We talk about creating millions of "shovel ready" jobs, for a society that doesn't really encourage anybody to pick up a shovel." 
Mike Rowe

"Old barns are a reminder of when I was young,
       and new barns are a reminder that I am not so young."
                          Rooster

Offline WILDSAWMILL

  • Full Member x2
  • ***
  • Posts: 100
  • Location: SW Mo.
  • Gender: Male
  • I'm new!
    • Share Post
Re: "cheating" post and beam construction
« Reply #4 on: May 23, 2009, 05:33:01 PM »
socket manufacting makes some. arkanasawer has used them he has a reference some were here or on wood web
i have been planning to but not yet
Kascosaw2B

Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #5 on: May 25, 2009, 11:44:33 AM »
Thanks for all the replies, the socket system brackets is kind of what I was looking for, they also seem really expensive for what they are, I may just buy some big angle iron and make something up myself.  Seeing some of the examples I'm wondering if my idea of construction is right, having 6X6 vertical posts then running 6X6 horizontal beams on top of them then just 2X6s on 24" centres between the two, then strapping I guess if I'm putting steel on or sheeted if I'm shingling.  This won't have a peaked roof , just like a stand alone lean-too. 

Any design advice/suggestions are appreciated

Offline Jeff

  • Fearless Leader
  • Administrator
  • *****
  • Posts: 51551
  • Age: 60
  • Location: Harrison MI
  • Gender: Male
  • Oh la di oh la da
    • Share Post
    • Behind the  Forestry Forum YouTube channel
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life.
Ezekiel 22:30

Offline WILDSAWMILL

  • Full Member x2
  • ***
  • Posts: 100
  • Location: SW Mo.
  • Gender: Male
  • I'm new!
    • Share Post
Re: "cheating" post and beam construction
« Reply #7 on: May 25, 2009, 03:47:33 PM »
I plan on welding my own as I want bigger post than 6x6 got some square tubing end cuts from salvage yard at good price
Kascosaw2B

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2076
  • Location: Canaan NH
    • Share Post
Re: "cheating" post and beam construction
« Reply #8 on: May 25, 2009, 09:16:13 PM »
Hi,

You can make your own big boy "nail plates" yourself or have a machine shop take flat 1/4" steel and punch holes in it and then fasten the plate to both sides of your beams with through bolts.  I think Simpson also makes some, but they ain't cheap either.

Jim brings up an excellent point though on an engineer approved setup.  If it were me, I would look at Simpson and copy the relative layout, enlarging the plan to fit my specs, and use 1/4 " steel and 1/2" through bolts.  You could then show this to an engineer rather than having the engineer come up with the whole thing.  I skipped the engineer and the through bolts and lagged steel onto the joints in my barn and it has held up fine, but if I was to do it again, I would thru-bolt.
Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Offline underdog

  • Full Member x2
  • ***
  • Posts: 122
    • Share Post
Re: "cheating" post and beam construction
« Reply #9 on: May 25, 2009, 10:13:47 PM »
Do a search on pole barns.
That is about the cheapest/easiest construction method.

Offline ARKANSAWYER

  • Senior Member x2
  • *****
  • Posts: 3048
  • Age: 60
  • Location: Wamego, Kansas
  • Gender: Male
  • Poor white Southern trash
    • Share Post
Re: "cheating" post and beam construction
« Reply #10 on: May 26, 2009, 01:25:35 PM »
 











  It is not cheating.  If they had steel square tubing they would have used it in times of old.  GrandPa would have killed for a box of timber tites and a cordless drill to run them with.

ARKANSAWYER

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #11 on: May 30, 2009, 01:51:47 PM »
Night Raider,

1) regarding cutting a beam longer than the normal sawmill span, there is a page in the knowledge base of the forum. Go to forum extras, knowledge base.  Here is a direct link:

http://www.forestryforum.com/tips/tips.cgi?display:1061208316-32360.txt

I neved tried it myself (and I would need a 25 feet beam, I'm not sure I have a tree that long that is big enough...)

2) I am also condirering building a shed over my mill.  However instead of  trying to use a 25 foot long beam, I'll build a truss using 6x6.  It might require more wood volume, and it will require more connector (pegged or metal) but milling nice 6x6x12.5 feet is much easier than a single 6x10x25 feet.

3) What is the snow load in your area?  To find the load on the beam you need:
a) figure out the ground snow load, the slope of the roof (minimal), the type of covering (slippery metal or non-slipery asphalt?) After that you must determine what portion of the roof snow load is distributed onto the beam. Then you can figure out what size of beam you need.   Here in Quebec, I have a snow load of 46 pound per square foot. With aspen, I can only reach something like a span of 9 feet with a 10x8, so I'd be a little bit surprised if you could reach 19 feet with a 6x10...



Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #12 on: May 31, 2009, 10:37:39 AM »
JFL. Thanks For the link.  I'm not sure of the top of my head what the snow load is but the beam would only be supporting 5' (10' wide building) it may have been a 6X12 beam.  And that was for hemlock, before I cut the beam I'll probably revisit the numbers.

For those with experience is it a bad idea to use a "boot" on a concrete peir to attatch the vertical posts or is it much better to anchor them directly in the concrete, The posts are pine so I was hoping to keep them up a bit and use sonotubes to make peirs that are a few inches above ground.

Thanks for all the info.

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #13 on: May 31, 2009, 07:45:33 PM »
Night Raider,

Here is my quick calculation:

Eastern hemlock  no 2 Fb=575 psi.

Compensate for  load duration (snow load= 1.15) Fb* = 660 psi.

6X12 (finished surfaces) @ 660 psi can hold 2807 lbs.

if your load is on 5 feet by 19 feet = 95 sq feet.

So that beam can hold up to a snow load of 29 lb / sq feet.  That's not a lot for canadian winters (Where are you in Ontario?)

jf

Offline moonhill

  • Senior Member x2
  • *****
  • Posts: 1379
  • Location: Down East, Maine
    • Share Post
Re: "cheating" post and beam construction
« Reply #14 on: June 01, 2009, 07:55:47 AM »
How many of these beams are there?  2, one on each end?  If so, that is twice the 29.  I am not sure I am following the whole design, I need pictures.

Tim

This is a test, please stand by...

Offline ljmathias

  • Senior Member x2
  • *****
  • Posts: 1315
  • Location: Purvis, Mississippi
  • Gender: Male
  • Been sawing part-time almost 27 years now
    • Share Post
    • Polymer Science Learning Center
Re: "cheating" post and beam construction
« Reply #15 on: June 02, 2009, 06:11:32 AM »
Setting posts in concrete has some drawbacks- holds the moisture in contact with the wood to promote rot while having the post elevated on a metal boot allows it to dry and stay dry- may not be as "solid" in some ways but works fine.  Other alternative is to use pressure treated and set 4' in the ground- works better here than in concrete.  Remember that ALL wood rots, just some slower than others, so at some point in the dim, distant future you may (will) have to replace a post or two, and it's a whole lot easier if it's attached to a boot- hard to dig it out of concrete.

Best of luck...

Lj
LT40, Long tractor with FEL and backhoe, lots of TF tools, beautiful wife of 50 years plus 4 kids, 5 grandsons AND TWO GRANDDAUGHTERS all healthy plus too many ideas and plans and not enough time and energy

Offline ARKANSAWYER

  • Senior Member x2
  • *****
  • Posts: 3048
  • Age: 60
  • Location: Wamego, Kansas
  • Gender: Male
  • Poor white Southern trash
    • Share Post
Re: "cheating" post and beam construction
« Reply #16 on: June 02, 2009, 08:03:02 PM »
 




I pour a pad and sonic tube of concrete to support the building.  This one is on a slope and we back filled it.  It is the support for Wanda's shed.


 




 Then I bolt a bracket like this and sit the post.  The post is cut to fit over the bolt in the center.


 





  This way if a post is damaged it can be replaced or spliced.  One buried in the ground it hard to work on.  Also Timber frames are a "point load" and just putting a post in the ground with out some extra support area in the bottom is asking for settling later.
ARKANSAWYER

Offline ljmathias

  • Senior Member x2
  • *****
  • Posts: 1315
  • Location: Purvis, Mississippi
  • Gender: Male
  • Been sawing part-time almost 27 years now
    • Share Post
    • Polymer Science Learning Center
Re: "cheating" post and beam construction
« Reply #17 on: June 05, 2009, 06:21:47 AM »
Right you are, Arky- just didn't finish all the details on the post in the ground- I usually infill with clean gravel or pour a footing for the pole to sit on to keep it from settling.  Course, that's if I'm not in a hurry which seems to be most of the time over the last few years.  Did my bigger pole barn with PT telephone poles set 4' in southern red clay and it's held up pretty good so far- about 6 years with so little settling I can't see it, but hey, I'm not looking all that hard either.

Lj
LT40, Long tractor with FEL and backhoe, lots of TF tools, beautiful wife of 50 years plus 4 kids, 5 grandsons AND TWO GRANDDAUGHTERS all healthy plus too many ideas and plans and not enough time and energy

Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #18 on: June 05, 2009, 08:08:46 AM »
jfl,
I'm looking at a snow load of up to 38 lb/sqft so I need a beam to hold about 3800lbs.  I didn't entirely follow your calculations.  I'll have to try to dig up my calculations, I quickly put in my number in the forum beam calculator and it seemed to "pass" I think (I'm not sure I entirely understand it).  I'm having a hard time finding something I difinitivley trust.  The building code seems to only talk about laminated dimensional lumber.
Arkansawyer, That's what I was thinking of using for the posts, that one looks a lot heavier then I was thinking but no reason I should go light.

Thanks for all the help

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #19 on: June 06, 2009, 08:00:10 AM »
OK I did my calculation a little bit fast and working with assumption maybe wrong. Here is the corrected detailed version:

In Don's calc:
http://www.forestryforum.com/members/donp/beamclcNDS2.htm

I entered the following:
Load on Beam(pounds): 3800  (in fact 19 ft x 5 feet x 38 is more 3610, but let's stick with 3800 for now)

Span of Beam (inches): 228  (19 feet x 12 inch per foot)

Width of Beam: 5.5 (you mentionned rough 5.5 in your initial post and that's also the finished size of a 6x6 lumber)

Depth of Beam: 11.5 (it should be 11.25 if it would be surfaced commercial wood)

Here is the funny part: the woord design values.  What number are you using?  I'll make assumtion (which should reveal to be false) and you can correct me afterward:

Hypothesis 1: you take the number from Don's link from the calculator:
http://www.forestryforum.com/members/donp/Fblist.htm

The best numbers are:
Eastern Hemlock Beam and Stringer
Select Structural  fb=1350 PSI MOE=1.2 Million PSI Fv=155 PSI

One nice thing with canadian snow load is that it is only present in the winter... So we can compensate with a factor CD= 1.15 since the duration of the load is only 2 months (I wish...)

In fact, one should check if the all-year-long load (without the snow) is ok with the all year long strength and check if the winter load (with the snow) is ok with the winter strength.  However, the snow load is so dominant around here (for that beam at least) that we don't really need to check the rest.  You might also have to check for the wind load, especially if the mill will be exposed to wind, but I can't help you on that. Also if the wood is wet, its strengh has to be reduced. But let's assume that you'll put a good roof over that beam... Now let's go back to fb

F'b = 1350 x 1.15 = 1552.5 psi
F'v = 155 x 1.15 = 178.25
MOE isn't compesated for duration, so it stays a 1.2 million psi.

I enter this into Don's calculator and get:
PASS, FAIL, PASS for Fiberstress in Bending,  Deflection,  Horizontal shear .

Deflection is between 1/240 and 1/360, so since you are not going to use gyproc on that ceiling, It might work for you.

However you just used a top quality beam (no knots, no checks, no split, wood slope less than 1/15) . Well, in fact Select Structural Beam and Stringer isn't perfect wood, but it must be a nice piece of wood (at 6x12x19 feet).  You mentionned previously that you are going to use rough lumber and I'm under the impression you want to mill it yourself. I personnally wouldn't try to grade my lumber as Select Structural (unless it is really perfect) and I'll design my shed with #2, which is easier to mill/find.  Let's try that:

No.2  fb=750 PSI moe=0.9 Million PSI fv=155 PSI

so F'b = 750psi * 1.15 = 862.5
Moe stays 0.9 and f'v is the same for #2 grade:

Now I get fail, fail, pass. 

So now the beam should fail with the snow load. And it will deflect more (closer to 1/240)  If you reduce the load to 3610 lbs (like mentionned in the beginning of the post) it will pass the Fb test, but not the deflection.

So you should check if you care about deflection.  If not, can you produce a beam that will be that large and nice enough to meet the grades of B&S #2.  I still think a truss would use a few more connectors but it would be stronger and wood would be easier to find.




Offline Night Raider

  • Full Member x2
  • ***
  • Posts: 105
  • Age: 36
  • Location: Kitchener/Waterloo Ontario
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #20 on: June 06, 2009, 08:54:18 AM »
jfl,
Thanks a lot for explaining that.  What did you mean by truss?  The slope runs perpendicular to this opening, but building a truss is appealing too, I wasn't looking forward to trying to handle a 20' log that big.

Thanks

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #21 on: June 07, 2009, 07:45:57 AM »
Night raider:

Here is a link to a thread on the a milling shed:
http://www.norwoodindustries.com/townhall/viewtopic.php?t=2190&highlight=sawmill+shed+truss

What I mean by truss is exactly what is shown on the last photo, copied here for your convenience:

 



I'm not saying that this design is exactly what you need, or that 2x4 or 2x6 will be good, that's the idea.  What I intended to do personnally (I'm looking for a 10x24 shed) is to use 6x6 and build a 6 foot high by 24 foot long truss:




On the top member, there is the bending load and the compression load.  Those have to be checked and might require a larger piece (6x8 maybe? I haven't looked at it)  All the other member work in compression or in tension. I'd use don's column calculator for the compression one.  Just to illustrate, let's calculate that for my shed:

The total load shown on the model is 50+100+100+100+50 = 400 (I was playing with shaped) Your load is 3800, so lets say that the number in that model have to by multiplied by 10 to fit the reality. So the largest compression force is 212x10=2120 lbs in compression. Since it is in diagonal, the member length is 6 x 1.4142 =8.5 foot or 102 inches. I punch those numbers into don's calculator at:

http://www.forestryforum.com/members/donp/columncalc.htm

I use the cheapest wood I have on my property (aspen: Northern Species #2, Fc = 350 MOE = 1.1 million) and I get a column capacity of 23931 lbs, so way above what is needed.

For tension, as far as I know, there is no stability factor to take into account, so you just multiply the surface by the strength, so 6x6x275 psi= 9900 lbs.  Still many times more than needed.

The difficulty will be the connectors. The connectors also have to support the compression or tension strenth. That is as far as I got into my reasonning, but I'll be checking the metal connector mentionned above in that thread: it looks like what I need.

jf

Offline Brad_bb

  • Senior Member x2
  • *****
  • Posts: 4609
  • Age: 50
  • Location: Joliet, IL and Indy
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #22 on: June 09, 2009, 01:05:55 PM »
Why post and beam?  I mean, as my timberframe teacher once said, "It will take the same time or less to cut real timberframe joints than it will to fab the metal brackets and fit them, so why not do the real thing?"  No metal means no rust or rot from the interaction of metal and wood and water. 
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #23 on: July 22, 2009, 09:26:16 PM »
Why post and beam?  I mean, as my timberframe teacher once said, "It will take the same time or less to cut real timberframe joints than it will to fab the metal brackets and fit them, so why not do the real thing?"  No metal means no rust or rot from the interaction of metal and wood and water. 

I'd be interested in doing the real thing, mostly for cost (8x8R post cap to put a beam on top of a post from Simpson StrongTie is something like 140$!), but then I bought a few books, including "Timber Framer's Workshop" from Steve Chappell and researched in this forum and I found out that it joint have to be build tight, at least to 1/32th of a inch or 1/64th.  I have problem cutting wood up to 1/8th of a inch with a skill saw... (ok ok, maybe I can be as precise as 1/16 of a inch if I take my time and use a guide). But I don't see how I could be more precise than that with a wood chisel? Correct me if I'm wrong but if the joint isn't tight, it will not hold (be strong and reliable).

This brings me to how long it takes to make a joint: I've already read a thread on that subject a long time ago and I don't remember any conclusion: It depends on the joint. 

Which brings me to another question: Most of the time, traditionnal timber framing is done with wet timber, mostly because it would take forever to dry them and them (unless you use salvaged lumber).  Is it more difficult to chisel dried timber than freshly cut timber?

Don't get me wrong: I think Timber framing is an art and as such it's worth more than industrialy produced stuff.  But to hang on the wall, I'll take buy the cheap reproduction of the Mona Lisa (poster) instead of a an original painting from a living artist...

jf

Offline witterbound

  • Senior Member
  • ****
  • Posts: 443
    • Share Post
Re: "cheating" post and beam construction
« Reply #24 on: July 22, 2009, 11:03:32 PM »
How long does it take to cut a joint?  It depends on many factors, principally, what kind of tools you have.  For example, I can cut a 2"x6" mortise with my mortise machine in about 5 minutes.  Then if I want the joint housed, it takes about 20 minutes for the housing, which I often rough out with a forstner bit.  I've found that I average about 45 minutes for most joints.   

Laying out the timber and joinery often takes as long as cutting it.  As with everything, you get better with practice (and more tools!).  I believe you will find that traditonal joinery has many rewards, but it takes time to do.  The metal connectors will save you a lot of time, if that's a constraint.  Just like most things, quality takes time.

Before you venture down the road of doing it the old way on a big project, start with something small.  You really need to attend a workshop or find a local timber framer to give you some learnin' before you tackle anything big.  You can't learn it all from a book.

Yes, it's more difficult to chisel dried timber than green.  Much more difficult in my experience. 

Offline Jim_Rogers

  • Board Moderator
  • *****
  • Posts: 7776
  • Age: 69
  • Location: Georgetown, MA
  • Gender: Male
  • Keep your chisels sharp.
    • Share Post
    • jrsawmill.com
Re: "cheating" post and beam construction
« Reply #25 on: July 23, 2009, 10:54:36 AM »

and I found out that it joint have to be build tight, at least to 1/32th of a inch or 1/64th.  I have problem cutting wood up to 1/8th of a inch with a skill saw... (ok ok, maybe I can be as precise as 1/16 of a inch if I take my time and use a guide). But I don't see how I could be more precise than that with a wood chisel?

We have discussed, here on this forum, and on other forums about timber framing the level of accuracy or the amount of "tolerance" allowed with joinery. Once in my research of tolerance of joint connections, I walked around a conference trade show asking each timber framer I saw what did they consider the correct tolerance between two mating surfaces. And my questions was; "is a business card thickness between two parts of a joint to much space?" A standard business card is about 20 thousands of an inch as I remember it.
Some said yes it was too much, some said no. I felt like I was getting as many different answers as the number of people who I asked the question.
When I asked this question of the framers who take about old structures and they said they have seen as much as 1/8" gap between mating surfaces. Well of course they would, as these structures they are repairing may have stood for 100 years or more. And the timber should be completely dried out.
When I asked the engineers in the group, they said that load goes to stiffness. That means to me that if a joint is sloppy and loose then it doesn't have very much strength in holding up a load.

We often hear the phrase: "you learn from your mistakes." Well, this is true, but I like to learn from other people's mistakes and I've seen many, at times.

One that really stands out to me, and I learned a lot from this beginner, was about tolerance. He asked an engineer, a well known timber framing engineer, about tolerance between mating surfaces of joints. And the engineer told him it was ok to make sloppy joints, and what he explained was that the tenon could be 1/8" thinner then the mortise. So this beginner did that, and constructed his house addition with loose fitting joints.

I have been back to this addition since I helped him raise it. It has stood for several years now, and it doesn't look like it's going to fall down anytime soon. But, the wood has dried out a lot over the last few years and things have started to happen. Some of the joints have really opened up. Some timbers have really twisted. He used Douglas fir tie beams, for strength, but didn't put the correct tenon on the end and used a small spline instead. There was nothing to hold the timber true and it twisted out of the plane of the bent.

You have to understand and compensate for the drying of the timbers when using green wood. If you leave a gap there now, how big will the gap grow when it dries out? And what will the effect to the frame be if it does grow to be a bigger gap?

In my opinion, there shouldn't be a business card thickness between joint mating surfaces. If you cut a 2" mortise then the tenon should be 2", less just enough for it to slide together easily, without pounding it together with a commander. And not too loose.

To check joint tolerance, we use a framing square to go into mortises:



And to check the tenon we set a caliper to the outside of the framing square and use it on the tenon:



And then to check the tenon like this:



If the tenon is too thick then the caliper will leave a scratch mark on the tenon. Remove the scratch marks with either a chisel, slick or plane and the tenon should be the correct size.

Quote
Correct me if I'm wrong but if the joint isn't tight, it will not hold (be strong and reliable).

Correct it should be the right size, but not over tight.

Quote
Is it more difficult to chisel dried timber than freshly cut timber?

Yes, dry wood is harder than freshly cut timber.

As to how long it takes to cut a joint, as mentioned, it depends.....
The more experience you get the faster you go, without sacrificing accuracy.

At workshops, I've seen a beginner timber framer, a middle aged man, take 4 eight hour days to cut all the joints on one post. In the same workshop, I saw a teenager, cut four timbers in four days. It all depends on the skills of the person.

Welcome to the forum and
Keep asking questions.....

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Offline Brad_bb

  • Senior Member x2
  • *****
  • Posts: 4609
  • Age: 50
  • Location: Joliet, IL and Indy
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #26 on: July 23, 2009, 11:24:22 PM »
It seems to me that jfl has some misconceptions due to lack of learning.  Don't shut yourself off to learning about timber framing.  I also highly recommend a attending a workshop.  Even if you will not be building yourself, you learn a lot at a workshop, not only tons about timber framing and getting some hands on experience, but you learn principles and techniques that you can also apply to other types of building, wood working, and more.  I think most of us TF'ers are always open to learning, well most of us anyway. 

Heck, believe it or not I just attended my second workshop that was hand tools only, and I learned how to properly use a hand saw.  It's amazing to me how this simple skill has disappeared in both construction personnel and your average DIY craftsman.   With a properly sharp handsaw and knowing the proper technique, you can make very precise and very square cuts.  You can make much more precise cuts than with your circsaw. 

Today I actually taught my cousin how to use a handsaw.  He has used one many times in the past, but told me he never could get a straight or square cut.  Well today in just 5 minutes of instruction, he made his first precise, square cut with a hand saw.  Trust me, once you gain this knowledge, you'll be reaching for your good handsaw more often than your circ saw. 

But back to my point... like with the handsaw example, once someone shows you the technique, and educates you on the theory, you'll see that things are not as complicated or difficult as you now believe. 

Do a workshop, and I bet you will then want to TF it.  There are many things to consider for your case, metal and wood do not mix well in the long term. 

The time it takes to cut a joint?... It depends on you and your tools, and a little experience.  Just don't forget that while it takes a certain amount of time to cut a mortise or tenon, in post and beam you have to take time to fabricate the brackets, seal them somehow to try and get a little more protection, and you have to fit the brackets and hardware.  It makes me wonder if there is any time savings, or if there is, how significant is it?  Weigh that against the quality of what you are building too.. 

Don't be scared about precision in TF'ing, like it's some magical skill.  You can cut joints as precisely as anyone else.  You learn how to do this with the techniques you are taught, which are what all TF'ers are taught or learn.  I never would have thought it, but now that I've learned the proper way to use hand tools, I find myself reaching for them more and more.  I love a sharp hand saw, and a good brace and bit.  I hope we can lure you over to the good side of the force!
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #27 on: July 24, 2009, 07:44:08 PM »
Brad,

I understand I'm on the wrong side of the force... but a little bit of background of where I am and where I'm going would explain better what I mean.

WARNING: GOING OFF TOPIC!

Ok, I bough a land 9 years ago, so my wife can have a barn (later in her life) I had a house built on that land in 2005 because my wife (finally) got pregnant (you could say that's my fault if we didn't succeed earlier, but now we are getting too far from the topic  ;) ) Now I have 2 children, a forest to clean (I got a mill) and a few OLD machines (backhoe (1991), Bombardier J5 (from 1962) with claw trailer and 10-ish years old lightweight equivalent of a timberjack but using track instead of wheel and chain, and also a 1972 bobcat skidder).  I can tell you that A) I'd not very funny to remove snow from them before we can use them at winter B) they don't start very well in the winter C) Their seats are all cracked, so whenever it rains (every second day!) the seat get wet for a week, but mainly D) changing frozen oil at -15 degree in 2 feet of snow isn't fun.

So the plan is to build a roof over those machine the fastest and cheapest way. I have plenty of aspen on my land (large enough to build 8x8 beams, but not 12x7. (See Thread : http://www.forestryforum.com/board/index.php/topic,32299.0.html) So I see the construction using timber (to include both post-and-beam and timber framing) as a way to build cheaply because I'm using my timber.  As such the best information I've found relating to the engineering of post and beam was in the Timber framing book (A Timber Framer's Workshop from Steve Chappell) rather than post and beam books.

Regarding learning and going to a workshop, I would really like to.  But let's face it (unless I don't really understand what it is, which is possible... you know, I'm French and Canadian officially, so a lot of words may be mis-translated when I read them) So I understand that a workshop is an intensive course (with hand-on practice), spanning many (2 to 5 maybe) days. This must cost from few hundred to a thousand dollars. I've seen offers in various States (in the US). My only problems with workshop is A) time, to get there (away from young children) and B) associated cost (travel, course). This is not getting me closer to my goal to build something cheaper than with purchased 2x8.

There is also the taxation. Here the tax man is terrible. If I build something nice, they are going to evaluate it like it's worth a million dollar (with no relation to the actual cost of the building) and then tax it at 20k to30k per year. No that's not a joke. People who has small farms with a barn have seen their tax bill rise by a factor or 3, 4 or more in the last 5 to 10 years. People who lived in their house for 30 year can't live there anymore just because of the evaluation of the stable... But that's also off-topic.

On the OTHER side, I lended all my books to my father (who if few month from retirement) and he mentioned me that I should I showed him that 30 years ago (when I was 5? ???) because he that's what he wants to do (he started practicing, did a dovetail!)

So I must wear both the dark side and light side hats.  When I put the dark side hat, I have to build a shed fast and cheap.  When I put the light side hat (when I want to have fun, and I can take my time) I want to build a timber frame.  But that first frame cannot be the 40x36 machinery shed I need ASAP...

Thanks for reading me.

jf

Offline ljmathias

  • Senior Member x2
  • *****
  • Posts: 1315
  • Location: Purvis, Mississippi
  • Gender: Male
  • Been sawing part-time almost 27 years now
    • Share Post
    • Polymer Science Learning Center
Re: "cheating" post and beam construction
« Reply #28 on: July 25, 2009, 06:54:54 AM »
jfl: I can identify with your plight in several ways.  I have 5 grandsons and a brand-new grand-daughter that demand (at least that's how I see it) that I be around to play with them lots.  I also have older equipment all with cracked seats that absorb rain and give it back to the seat of your pants for days or weeks.  Looked at new tractors yesterday, and the one question I asked every dealer was why the manufacturers use such lousy material for their seats.  Only useful answer was: use lots of garbage bags to cover up the seats so they don't crack or don't absorb water when they do.  Why not just be a good seat?  Must be a huge market for them- I'd buy 7 or 8 right now if I knew they'd last for several years instead of the two max they last now.

Back to topic: I have built several barns and sheds to get equipment out of the rain and sun (it's the sun that causes the seats to crack) and every time I get one built, I end up using it for something else- storing Katrina wood in, storing lumber cut from trees so they can air-dry, storing firewood, storing an old jeep and my sons ocean boat, working on timber framing projects and woodworking...  Seems I can 't build enough barns and sheds fast enough.  I sympathize with your quick-and-dirty approach, done it myself on several of my buildings like the sawmill shed I finished yesterday so I could hurry-up and get the LT40 out of the weather, but in the end, I want the buildings to stand during my lifetime (whatever's left) and for my kids and grandkids to use during theirs.  Tough compromise and there's no easy answer.

Short answer: balance building fast with longevity of what you build, and keep at it.  Love the wife and kids while you're doing it, and as Jim says in his signature, whatever you do, have fun doing it.

Lj
LT40, Long tractor with FEL and backhoe, lots of TF tools, beautiful wife of 50 years plus 4 kids, 5 grandsons AND TWO GRANDDAUGHTERS all healthy plus too many ideas and plans and not enough time and energy

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2076
  • Location: Canaan NH
    • Share Post
Re: "cheating" post and beam construction
« Reply #29 on: July 25, 2009, 09:04:42 AM »
Sounds to me like a pole barn is the way to go....  Or maybe a purchased steel outbuilding (used???)..

Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Offline beenthere

  • Senior Member x2
  • *****
  • Posts: 27074
  • Location: Southern Wisconsin, USA
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #30 on: July 25, 2009, 10:20:18 AM »
Off topic, but following through the open door..........

I like the comfort of the newer tractor seats, and wouldn't want to go back to the iron pans that stood up fine in the weather. If I have to leave mine out in the rain, I tilt them forward so the rain doesn't puddle in the seat and soak in. ;)
But I can't leave equipment out in the sun and rain, so I keep putting up more shed.  :) :)
south central Wisconsin
 It may be that my sole purpose in life is simply to serve as a warning to others

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #31 on: July 25, 2009, 08:17:43 PM »
Sounds to me like a pole barn is the way to go....  Or maybe a purchased steel outbuilding (used???)..

Yeah, I'm considering that. I'm on their mailing list and I get the end-of-year special. But the building that seems nice to me is 30-ish k$. The 10k$ ones are not high enough for the backhoe.  now to hold the roof I'll have to build a full foundation (ho, I feel here I'm doing bad translation... What do you call the concrete wall you put the the building wall on?)  I wanted to do concrete pier, but then how where does wall sit on? If I would build a cabin or house, I could just jack it up and build a wood floor.  But I don't think I can build a floor strong enough for machinery.  And with the frost I can't have the wall resting on a bed of gravel (Can I?) so I'm a little stuck with concrete foundations...

jf

Offline Brad_bb

  • Senior Member x2
  • *****
  • Posts: 4609
  • Age: 50
  • Location: Joliet, IL and Indy
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #32 on: July 25, 2009, 10:56:36 PM »
jfl, I just didn't want you to unfairly rule out TF, because of lack of experience/understanding, or misconception.  It sounded like you were when you mentioned your ability for precision etc.  It also seemed like were thinking brackets were faster than joints without considering time and cost to fab the brackets and fit them.

I understand that all things must be considered for such a choice.  For the last two days, my cousin and I have been rennovating the open add on of my shop which formerly housed cows.  It's a polebarn and I'm enclosing and sealing it to be heated storage space (to clear space in my shop to timberframe).  I only plan to be in this shop for max 5 years, so I am rennovating with stick framing.  If it were my permanent shop, it would be TF.  I'm doing this so that I can build my new workshop timber frame.  My cousin kids me saying, "This is not a show builiding Brad".  He's saying I'm too detailed and thorough, as if I do everything like the show cars I've restored.
But I digress, sometimes it must be quick and dirty, and sometimes doing it the best way should be considered, and sometimes in between.
Bon chance, mon ami Canadien! 
Anything someone can design, I can sure figure out how to fix!
If I say it\\\\\\\'s going to take so long, multiply that by at least 3!

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2076
  • Location: Canaan NH
    • Share Post
Re: "cheating" post and beam construction
« Reply #33 on: July 25, 2009, 11:09:00 PM »
JFL,

If you pour a one piece concrete "monoslab", it will rise and fall with the frost and would save you some digging.

BRad,

How would you inexpensively insulate a timber frame and still have the timbers showing?
Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Offline jfl

  • member
  • *
  • Posts: 31
  • Age: 48
  • Location: Montreal, Canada
  • Gender: Male
    • Share Post
Re: "cheating" post and beam construction
« Reply #34 on: July 26, 2009, 08:00:48 AM »
JFL,

If you pour a one piece concrete "monoslab", it will rise and fall with the frost and would save you some digging.

Yes, that's exactly what I though initially. But initially, the shed was more like 24x32.  I've been discussing with peoples (architects, builder's) and I'm starting to think that the monoslab would have to be so thick that it would cost more than full fundations.  And digging is (almost) free (because of the backhoe I'm trying to put in the shed).

Do you have any experience on up to what size a monoslab make sense?

Thanks,
jf

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2076
  • Location: Canaan NH
    • Share Post
Re: "cheating" post and beam construction
« Reply #35 on: July 26, 2009, 10:10:40 AM »
I am no concrete guy.  I would talk with one or two in your area and discuss the pros and cons of stemwall w/slab vs monoslab.  I would think the concrete amount would be similar either way if you were planning a slab for the stemwall.  Either way, pay close attention to insulating the slab/foundation.  I would have that conversation with the concrete guys also.

I have done a few stemwall slabs but that was in Oregon where I only had to go down 18 inches. Here in NH if I would have to go  down 6 feet so I would want to make a full basement while I was down there, but that doesn't make sense for you.

Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Offline moonhill

  • Senior Member x2
  • *****
  • Posts: 1379
  • Location: Down East, Maine
    • Share Post
Re: "cheating" post and beam construction
« Reply #36 on: July 26, 2009, 11:07:37 AM »
I don't believe a floating slab is suggesting it will float on the frost.  It floats on the ground and if frost get under it you could have an issue.  A floating slab allows you to not dig a trench for the frost wall.  But is advisable to insulate around the perimeter of the slab at least, and under it if you are going to heat the slab and you have the extra cash.  Frost would have to penetrate through the top of the slab to get under it.  With a structure over the slab you greatly reduce the night time radiation heat loss.  Now your driveway exposed to the night sky will have far greater chance to have frost build up under it.  Well drained soil is a plus. 

I also think it would take more time and energy to fab steel plates than cut joinery, my bias opinion. 

Tim
This is a test, please stand by...

Offline slowzuki

  • Senior Member x2
  • *****
  • Posts: 1242
  • Age: 2017
  • Location: New Brunswick, Canada
  • Gender: Male
  • Still learnin'
    • Share Post
    • On the Farm
Re: "cheating" post and beam construction
« Reply #37 on: July 30, 2009, 01:40:24 PM »
I was in your position with equipment to cover on new property.  I built a socket systems building which went up very easy.  I'd guess that my beginner skill on steel sockets was as fast as a pro timberframer.  But I sure like the look of proper timber frame.

If I did it again I would have built two buildings, a house and a shop.  I would have built a pole barn or fabric building for the shop.  Pole barns go up fast and cheap as long as you don't need to mess with insulation.

In NB, fabric buildings aren't taxed as permanent as long as you don't have a slab.  Saves lots of money.

One of the better companies is:
www.HiqualProducts.com  but they are pretty expensive compared to the cheap ones.


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

 


Powered by EzPortal