Posts

[alex trent]

Planning underway for a 24X40 on concrete piers and wood posts. Three rows of posts (walls and center) will be 6x6 or perhaps 8x8 and will support beams.

My thought is to run the posts up to the top of the wall...10 feet above the deck/floor line. Frame with studs as necessary between them to support top beam on top of big posts.

Two main questions:

1. Is there any disadvantage or advantage to this vs. traditional wall framing where the post do not continue up beyond the floor beam?

2. I had planned to notch the posts and inset the beams into the notch.  With the posts going on up, this presents a problem.  Is hanging the beams on the posts with lag bolts really that bad?  What about a notch in the posts that goes back to original dimension above the beam...like a square "c" cut into the post. Then the top of the post goes back to being an 8x8 above where it is cut out to accept the 4x10 beam?  If the cut in the post is precision, the top of the post will now rest on the beam where it is inside the post notch.

[Don_P]

Great minds think alike  . I've been drawing something along those lines ever since you started your thread earlier. Your square C notch is called a table and in TF is often 1". It accompanies a mortise and tennon joint but provides full width bearing rather than bearing just on a 2" tennon's edge, used for heavily loaded timbers.

The inserted beam into the post might be tight the day it is inserted and as the shrinkage is in opposing directions that is the last day it is fully tight... so that logic is incorrect.

and yes the reason I was thinking on full height posts is that the walls are now bracing the posts.

Simpson makes an inturned hanger with just about the right capacity as well, HUCQ,
http://strongtie.com/products/connectors/HUCQ.asp

[alex trent]

Well, I am not too sure about the great minds thing from my part.  There has been overwhelmingly good information provided...makes me rethink if this is more than I can handle. I need to do it a bit at a time.  Thanks to all.

On your last post, I take it posts all the way up are OK or even good. One of my main reasons for doing it here is that it makes wall framing easier in a non-framing environment.  Roof expertise is great, but on adobe or block walls.

And, I take it that the table end of putting a 3 or 4 inch beam inside a notched 8 inch post is not a great idea. I can see why.  I'd be hammering shims forever. You think these hangers are better than bolting on the front and spanning three posts. Looks easily doable to me if hangers are better.

[MountainDon]

The hangers are designed to carry and distribute the load through a number of nails. Bolts through the timbers, which places the load on the bolts and points in the wood where the bolts penetrate is weaker.

[alex trent]

Tks..another "what looks logical" building idea dispelled. A bunch or little nails better than 3 3/4 lag bolts.

This is what I meant when I said, the more I know, the more I do not know what I don't know.

I am good at picking stuff apart, so as long as you guys have patience.....

[Don_P]

And actually in that hanger their SDS screws are specced. I did some quick math and there isn't much to spare so recheck before going that route. But yes, since wood is not particularly strong per unit of area, many small connectors are often better than a single heavily stressed connector.

Posts all the way up are a good thing for bracing. The joinery at the floor level is the next hill to climb going this route.

8x8's are in my mind here. The table, or parallel housing, is fine. As long as it is allowed to sit down on the bearing shoulder no shimming is needed. I was just pointing out a thinking problem, the incoming timber does not replace the wood that was removed from the post.

If this is along the lines you are thinking go to the TF Guild website and download Sobon's "Historic American Timber Joinery" for alot of good graphics

I worked on a frame several years ago that had much larger loads, 8x10 posts with 8x12's coming into 1" tables. To avoid any mortises they used timberlinx connectors from one beam, thru the post, to the beam on the other side. The connector pulled the beams from each side into the tabled areas on each side of the post. It preserved more post material but the timbers have now twisted and don't look that great. I think even a stub tennon would have helped hold them straighter as they dried. The timberlinx or fabricated bed bolts are a good tie for the joint.

[alex trent]

On the hanger screws and capacity. I  hate to "come close". Anyway I will be recalculating everything when it get it finalized and am already thinking of 6 foot spacing on the post vs the 8 we are discussing now, so that will bring the load down.

Let's see if I have this straight...a bit different in the table dimensions and the beam fit. I had figured the beam to got all the way into the table...like 3" or maybe 4".  But from what i understand now, it only has to go in 1"...is that correct?  This makes me feel better about cutting out the post as my 8X8 now becomes a 7x8, not a 5 x 8 as with my first thought.  7X8 should be OK, especially if I go to 6 feet on the posts.  I like the insert version better. Not sure why.

Yeah, the floor. Looks like I will need to hang he joists...original plan was to set them on top but I see now that with posts through that could be a spacing nightmare.  That is not a particular problem.  I will likely hang on the outside and overlap in the middle by running the middle beam lower that the outside ones.

I plan to do the floor diagonally even though it is a bit more difficult. Read that this adds a lot of "bracing" strength to the structure.  True?

at

[JRR]

Rather than cutting the "table" in the post, would it work to add a vertical sister "stud" (glued and lagged to the post) that would support the joists?  The sister would help reinforce, not weaken, the post and could extend all the way down to whatever the post rests on.  A 2x8, for example, would give a rest of 1 1/2" ... and not weaken the post.  A Simpson angle bracket could go between the sister and joist for additional load-spreading.  (The glue is used just to reject water penetration).

Bad idea??

[alex trent]

Sounds EZ enough to do and supports the beam (you said joist, but I assume beam) solid to the concrete pier the post will rest on.  I like the idea of not cutting into the beam. I think the beam will be 3 inches so I could use 3x8 as the "sister" and it all is flush.

If I put the beam on the inside of the post, I would get rid of some of the flooring problems with the posts going up as the joists could then rest on the beam and it is unobstructed by the posts. This assumes 3 inches is enough bearing area for the joist.

[JRR]

If a metal fence post cap was added to the sister, using a generous coating of PL flashing sealer underneath, there should be a good spread of load that resists splitting, as well as bugs and water.

[alex trent]

Anybody got  a problem with this way of supporting the beams with this vertical sister "stud" on the post....it will go down to the concrete  pier.  Seem like a nice way to get max support without having to notch the posts which will run all the way up to the sill plate and avoids hangers.

Also, any problem with putting the floor joists on top of the beams rather than on hangers?

[Don_P]

You'll need to calculate the load (reaction) on each end of the beams where they bear on the sister post. This bearing needs to be large enough to support the load without crushing into the beam. Quite do-able, just needs to be checked. The posts will likely be green, undried, and as they dry and get narrower some means of keeping the beam snug needs to be thought through. Maybe something like a piece of angle iron attached to each beam and the post.
Have you sorted out your species and its' design values?

[alex trent]

Right now it looks like cedro macho for the framing and the siding and guapinol for the floor and deck...

Guapinol is about 50% stronger and almost twice as hard as cedro macho, but is also about 40% more money and drys to a darkish red which will be too much.

Here are the links...

http://www.lumbermax.biz/species/jatoba.php

http://www.lumbermax.biz/species/caobilla.php


You can see cedro is stronger that SYP, so if I use the SYP specs that build me in some insurance as nothing is speced or inspected here.

If I can get it I may go to nispero for the posts...it is the chicle tree and extremely insect proof and durable.

For the cedro I will treat with Bora Care on the posts and TimBor for the floor and siding and other framing.

The framing will be two weeks from being a tree when it gets to the mill and i will give it another 4 weeks to air dry under an open shed. This is the  perfect time for that here as temps are 75-90 and humidity in the 70's. Still pretty green, but that is that. Floor is T&G and dryed...air for about a year,