Post knee braces to tiebeam

rjwoelk · January 25, 2023, 10:13:23 AM

the post in the center is 3/16 short of being tight. What is a better way of correcting this problem, lengthen the kneebrace mortise?
shorten the kneebrace?

Jim_Rogers · January 25, 2023, 10:52:43 AM

If the post is not sitting correctly you need to measure everything and find out why or where there is a difference that is holding it out.
Proper measuring should show you why.
Trimming in the wrong spot may make it worse instead of better.
I normally put the post into the tie beam first to make sure it seats correctly.
Then I put one brace into the post and make sure it seats correctly there. And then the other end into the tie beam and make sure it seats correctly there as well.
then do the other brace, both ends as well.
After I have test fit all these connections. Then I try to put all of them together.
If it doesn't fit, then measuring and trimming the correct connections is needed.
Measure the hypotenuse of the brace and the legs of the right triangle and verify that everything is correct.
Sometimes you'll find it sometimes you won't and just have to trim the braces a little to get them all to fit.
Good luck with your project.
Jim Rogers

rjwoelk · January 25, 2023, 10:59:52 AM

Jim.
The post fits tight by its self. The knee braces fit nicely in their respective mortise but together I have this gape and the knee braces are tight. All measurements were done with the post in place and tight.
I just thought of something, this tiebeam may have a slight crown to it, I will check that, as that could be causing the problem.
Robert

Jim_Rogers · January 25, 2023, 11:04:37 AM

A crown may cause that as well.

Sometimes we leave post long until we're sure of everything and then trim to length.
If you have already cut to length, then you may need to shim the bottom of the post to make sure it sits on the supports.

Jim Rogers

rjwoelk · January 25, 2023, 11:13:53 AM

The center post is long and can be trimmed later.
If there is a crown or not, could I deepen the kneebrace mortise housing? in the tiebeam

Jim_Rogers · January 25, 2023, 11:55:45 AM

You can if you wish, but again you should carefully measure everything, and see if you can find the area to improve.
The housing shoulder should be the correct distance off the top of the tie beam. If it is not then that could be the reason why it is holding the post out. Check both brace housing to the tie beam. If one is not deep enough, then the other maybe the same.
if the brace tenon is bottoming out in the bottom of the brace mortise then it will not allow the brace to seat, this could hold the post out.

Jim Rogers

timberframe · January 25, 2023, 12:40:09 PM

You could run a string line along the bottom of the beam to see how much of a banana shape there is, and where it is if not symmetrical. If it's mild and centred right in the middle, it might not explain all of the 3/16 because the braces are up into at least part of the banana too. Verify the brace length and that they're touching everywhere on their faces. Don't change the length of the braces if they're correct, because changing length, also changes where they land along the timbers not just up and down. If you have to, (and only do this if everything else is checked out) you can move the end of the braces on the post down towards the post bottom and that will let the post shift upwards vertically without pissing of Pythagorus.

This is why I use a version of line rule that always accounts for this. I have never test fit timbers before leaving the shop....if I haven't screwed anything up, they always go together.

Jim_Rogers · January 25, 2023, 02:44:42 PM

timberframe:
You have much more experience and training that most of us, including me. And as I work with beginners all the time, I feel that test fitting is better than trimming a tenon or mortise up in the air on a ladder when something won't go together right.

Thanks for your comments.

Jim Rogers

rjwoelk · January 25, 2023, 02:47:59 PM

Ok the tiebeam is got a crown. So address this by lowering the kneebrace mortise on the post by the amount of 3/16?

rjwoelk · January 25, 2023, 02:53:08 PM

Jim this is test fitting I am doing, its not in the air. I need to be accurate on the ground.
So timberframer thanks for the info.

Jim_Rogers · January 25, 2023, 03:08:09 PM

If you can't find any other place where the measurements are off, yes, that would be the best solution.

Jim Rogers

rjwoelk · January 25, 2023, 04:11:08 PM

Thanks for the information.
Will let you know how it goes together once I adjust it.

logman · January 25, 2023, 06:04:47 PM

I'd put a strap on the tie beam to the post bottom and try and pull it together first before I would cut anything.

rjwoelk · January 25, 2023, 08:55:50 PM

Well that solved the problem, fits perfectly. Thanks guys for the insight.

timberframe · January 25, 2023, 10:41:41 PM

Quote from: Jim_Rogers on January 25, 2023, 02:44:42 PM
timberframe:
You have much more experience and training that most of us, including me. And as I work with beginners all the time, I feel that test fitting is better than trimming a tenon or mortise up in the air on a ladder when something won't go together right.

Thanks for your comments.

Jim Rogers

Oh goodness yes! When I said run the string line on the "bottom" I meant the portion of the beam that is slated to be the bottom upon erecting but do this all on the ground before anything is stood up.