Speaking of floor framing...

[JavaMan]

I'd like to pick everyone's brain about how to square up my 12x12 floor joists/frame.

I took measurements before I left, and knew it wasn't quite square, but thought it might be "square enough" ... after doing the math, I know it's not.  I'm off by 3.3" - quite an overhand or underhang in my estimation.

Other than a big sledge to whack it into square, (or pulling every nail from the ties and squaring it up) is there an "easier" way?

Thanks

[MountainDon]

What's the setup you've got?

A couple of beams with joists sitting on top, nailed in place? Rim joists installed on the joist ends?

Or some other setup? Pictures would/could help.

With some more insight someone can likely help.  




For future reference for anyone reading this... assuming one is building on a post and beam foundation, the place to start when setting up for a square floor is to square up the posts and beams to perfection. My beams were not absolutely parallel due to a large rock I preferred to leave in place. (It was found when digging for post 8 or 9) So I went with an out of square pair of beams and squared the joists on the beams and going on from there. I made the beams over length to begin with. As illustrated I began with the first and last joists on the beams and squared the ends of those up before going any further. I got the diagonal to within 1/8" using steel measuring tape. I trimmed the beams to length later.

For other foundations there will be some differences in the approach, but get the basic foundation square first is usually the best.




Another direction of attack would be to square up the beams first,

[Redoverfarm]

As Don stated there are a lot of things that could produce this but before you start "wacking" I would measure again and try to determine what is the culpert. Then you will know what direction you have to go.  A "sawzall" will do a good bit without busting things apart.  Just cut what nails you have and re-nail it once you bring it back in.  If you don't get it closer it will haunt you from here on out as you proceed. 

[MountainDon]

I'll give a big 'second' to the sawzall. A sawzall with a metal cutting blade used to cut the nails is many times easier than trying to pull them.

[JavaMan]

Pictures ... you asked for it, you got it! 



This is the state that it currently is in.

Not owning a sawz-all, I guess I could probably use a hacksaw or something like that.  Sad to say, I think that is the direction I will probably go in.  Remove/cut the nails holding the frame to the beams and straighten it out until I get it square and then nail it back into place.

Grrr ... that is going to slow me down next time I'm up there.  Hmmm, I could probably grind the heads off with the grinder - that might work faster.

As you can see, I already have some additional work to do - placing a strip of 2X on top of the one board to ensure that it is all lined up right.  It's amazing how you can take your time and measure and work it 2 or 3 times and still get it just ever-so-slightly wrong.

[MountainDon]

- placing a strip of 2X on top of the one board to ensure that it is all lined up right. 

Have you tried that plank flipped, current upside edge moved to be the downside edge?

[JavaMan]

- placing a strip of 2X on top of the one board to ensure that it is all lined up right. 

Have you tried that plank flipped, current upside edge moved to be the downside edge?

That sounds like something my dad would say as a joke    But experience tells me that sometimes the most unlikely suggestions work.  I haven't tried that, but I may have to.  Unfortunately, that won't square it up, but it might help - now that I think about it.

[MountainDon]

I haven't tried that, but I may have to. 

Planks and boards frequently have a crown to them. That is is you were to place a 2x on edge on a known flat surface some of them will touch at the ends but not in the middle. That would be called crown up. Or it may touch in the middle and not the ends like rockers on a rocking chair. Crown can usually be seen by sighting down the plank. 

When you placed the joists on the beams did you eyeball them and place them with the crown up? It may be too late if you did not, so that is also for future readers to take note of. It is best practice.

[Pine Cone]

Not owning a sawz-all, I guess I could probably use a hacksaw or something like that.  Sad to say, I think that is the direction I will probably go in.  Remove/cut the nails holding the frame to the beams and straighten it out until I get it square and then nail it back into place.

Time for you to get aquainted with your local Harbor Freight or other cheap hardware/tool source.  There's one in Tacoma just south of the Narrows Bridge.  A few doors down is a Sears outlet store that sometimes has interesting stuff for cheap as well. 

In this weeks Harbor Freight flyer I saw two sawzall-like tools, one for $20, the other for $25.  This assumes you have power out there.   I think of their tools as disposable, but some have held up quite well.  I really like their cordless drills and have two plus a spare battery which comes in very handy at times.

It may be painful to cut the nails and redo, but it will save time, effort and grief in the long run.  You can also use the sawzall-like tools to do lots of other things so it will be a useful purchase.  

Keep those pictures coming...  

[JavaMan]

I've been to that Harbor Freight.  That's where I bought the drill for the fireplace project I did at Beautiful's house before we married ... I had to drill into CMU's and use some "special" anchors to mount the mantle piece...  With "blind" holes in the mantle board.  Shoulda seen her look at me when I said, "I hope these line up right - I've never done this before"  

Looked like this when we were done:


She was very pleased when it was finished...

We did the rock and everything - that was fun and it proved that we work well together 

And she still married me, so I guess it all turned out good  

I was just at their website, and saw that sawsall-like saw - and something else that I could use (of course, there are all the things that I will see when I'm there that I just can't live without )

Guess a short road trip is in the works

[NM_Shooter]

Don't cut anything yet...

1)  I noticed that your beam clips are not fastened yet.  If your joists are spaced correctly, but the total floor surface is not square, try shimming up your beams with something that will raise one beam out of the clips just a little bit.  With a BFH, tap on one of the beams to square the deck up, then drop it back down into the clip.  You might be able to square the whole thing up without removing a single nail.  IF this works, go back and fire in extra toenails on the joists into the beams when done.  You may need to employ a come along across the long diagonal to apply some help.

2)  The joists look as though they protrude 1" or so above the rim joist on the near side in the photo, but look flush on the other side.  Am I seeing that wrong?

I followed Don's actions.  I had rocks that were not going to come out, so my beams are not parallel.  I made my beams longer than required, and squared up the corners on the two end joists.  Then with strings attached to the end joists I placed the rest of the joists and it turned out okay.

[JavaMan]

Don't cut anything yet...

1)  I noticed that your beam clips are not fastened yet.  If your joists are spaced correctly, but the total floor surface is not square, try shimming up your beams with something that will raise one beam out of the clips just a little bit.  With a BFH, tap on one of the beams to square the deck up, then drop it back down into the clip.  You might be able to square the whole thing up without removing a single nail.  IF this works, go back and fire in extra toenails on the joists into the beams when done.  You may need to employ a come along across the long diagonal to apply some help.

Hadn't thought of that - I'll have to take a look at it when I get back up there and see if that will work - if nothing else, it's worth a try.  If it works - Great! if not, nothing but a few minutes lost.  Thanks!  My only  concern is that I might have to "tap" the beam far enough so that it won't drop back into the clip.  But if I can get it square in this manner, it might be easier to move the pier-block the small amount.

Of course, this assumes that I actually am understanding correctly what you are saying  

2)  The joists look as though they protrude 1" or so above the rim joist on the near side in the photo, but look flush on the other side.  Am I seeing that wrong?

Actually, it's not that bad - it's about 1/4" - 1/2", I think.  I was thinking of simply putting a furring strip on top there, but I may simply pop that board off, and realign them.

I followed Don's actions.  I had rocks that were not going to come out, so my beams are not parallel.  I made my beams longer than required, and squared up the corners on the two end joists.  Then with strings attached to the end joists I placed the rest of the joists and it turned out okay.

Ah, see, I didn't build the "frame" around and then set the joists.  That might have worked better.

Sometimes I wish I could just stay up there and have all this information at my fingertips.  And I could be more accurate in describing what is going on in pictures (like how much there is above the one joist end).  Then again, I might be spending more time just taking pictures to help answer all the questions you guys think up!  I really do appreciate it - it gets me thinking and planning better, so next time I'm up there, I can be prepared for things like this.

Thank goodness this is pretty much a practice run for the "real" cabin.  Of course, that one will be a bit different than the shed, being logs, but the flooring and such will still need to be square and well built!   

[SkagitDrifter]

With no sheeting on the deck you should be able to rack the frame into square using a come-along or even a heavy rachet strap.  You don't seem to have all that many nails in it.  If you are out of square 3" you only have to make up 1-1/2".  I would try that before taking anything apart.  Worth a try.
One way or another you need to get it square- you will be fighting it the whole rest of the project if you dont, walls, siding, the roof etc.
Good luck.

[JavaMan]

With no sheeting on the deck you should be able to rack the frame into square using a come-along or even a heavy rachet strap.  You don't seem to have all that many nails in it.  If you are out of square 3" you only have the make up 1-1/2".  I would try that before taking anything apart.  Worth a try.
One way or another you need to get it square- you will be fighting it the whole rest of the project if you dont, walls, siding, the roof etc.
Good luck.

Yup, that's what I'm thinking.  Being off 3" at the corners is a bit much.  I could handle being off 3/16" or something like that, but not 3 whole inches - and it's actually more than that - it's (by my trig calcs) 3.34"!  But I think I have to move it the entire 3.34", don't I?  After all, the 3.34" over hang at one corner means that it's shy 3.34" at the next corner.  Ah well, I'll find out when I get up there again.

Plans are to go up weekend after this one. (15th of May).  I might just have to enable the data plan on my phone again and figure out how to tether the computer to it 

[MountainDon]

it's (by my trig calcs) 3.34"!  But I think I have to move it the entire 3.34", don't I? 

You've confused me with that statement about trig calcs. You have measured the diagonals with a steel tape, have you not? Those two actual physical measurements have to match as closely as possible. No more difference of 1/8" is quite possible to achieve.

Maybe I misunderstood your first statement " I'm off by 3.3" to mean that one diagonal was 3.34" longer than the other, by physical measurement.

[NM_Shooter]

Note what Don says on how to measure this.. use a steel tape and measure from diagonal corners for the best and most accurate way to measure...

Also.. if when you try to rack that thing back into square, be prepared to use some diagonal nailers to hold it in place until you can get the sheeting on. 

[JavaMan]

it's (by my trig calcs) 3.34"!  But I think I have to move it the entire 3.34", don't I? 

You've confused me with that statement about trig calcs. You have measured the diagonals with a steel tape, have you not? Those two actual physical measurements have to match as closely as possible. No more difference of 1/8" is quite possible to achieve.

Maybe I misunderstood your first statement " I'm off by 3.3" to mean that one diagonal was 3.34" longer than the other, by physical measurement.

Ahh, I see - no, diagonally across one way it was 200" the other way 206"  Assuming that the two triangles are supposed to be right triangles, and that a²+b²= c², the diagonal measure should be 203.64"  Now, while that looks to be close to the 3.34" I was talking about before, I decided that I would find out how far off it would actually be on the corners.  Of course, now that I knew it wasn't square, I couldn't assume that the corners were square and had to find, via trigonometry, what the angles were.  So I dug out my trig book and used the Cosine rule to find the angles. (since I knew the length of all three sides of both triangles, I could do this)

From that, I could then calculate what the length of one of the sides of the actual right triangle formed by the sheathing would be - that leg that would either fall short or overhang the frame corner - and it was 3.34" (see crude picture below):


Obviously, not to scale ...

Odd that it should be so close to 1/2 of what the measure was off.  Coincidence? or conspiracy?     

I wanted to know how far off that was.  If that  distance was only 3/16", I might not worry about it, but 3+" I will be working to straighten that out before I go any farther 

[MountainDon]

That is a big discrepancy, IMO.  So are the sides all exactly 144" by tape? That would mean you trimmed the joists to make up for the thickness of the two rim joists.


Shifting one of the beams one way or the other is a great thought. If you have any luck at all that may be a dandy solution.


I don't want to sound like I'm being a nit picker, but I'm not clear on how this can be straightened out without cutting a lot of nails. If the joists were not nailed to the beams I can see how the parallelogram form could be slide into a squared up shape. At the very least I'd remove the rim joists and cut at least one of the two 'end' joists free. Then I'd make those two form a 'perfect' square or rectangle with the two diagonals tape measured to within 1/8". After that you see how much all the other joists would have to be shifted. I don't think there is an easy solution. But that's just my opinion.

[JavaMan]

I got to thinking and it may be that I can simply slide one of the beams a couple inches lengthwise and have the parallelogram straighten out sufficiently. 

But I think that might be a long shot.  I do think there will be nails that have to get cut.  And yes, I trimmed all the joists. All the sides are 144" exactly, by tape. (a 1", 25' Stanley, to be exact  )

I'll be reporting back here after the weekend of the 15th and 16th to let you all know how it went!

[soomb]

For future reference for anyone reading this... assuming one is building on a post and beam foundation, the place to start when setting up for a square floor is to square up the posts and beams to perfection. My beams were not absolutely parallel due to a large rock I preferred to leave in place. (It was found when digging for post 8 or 9) So I went with an out of square pair of beams and squared the joists on the beams and going on from there. I made the beams over length to begin with. As illustrated I began with the first and last joists on the beams and squared the ends of those up before going any further. I got the diagonal to within 1/8" using steel measuring tape. I trimmed the beams to length later.

For other foundations there will be some differences in the approach, but get the basic foundation square first is usually the best.




Another direction of attack would be to square up the beams first,

Perfect morning to check in on the site.  I am building my first project. A 10' x 10" office on a post and pier foundation in my back yard in Phoenix, AZ.  I have my foundation of 3 piers on 4' centers per side (2 rows = 6 total) and the piers are 8' OC from each other, from the first row to the second.  this design will allow 1' cantilever on all sides when measured from the center of the beam.  I have a 10' PT beam set and ready to go.  Everything is level.  I pre-nailed Simpson Strong ties to the beam to be able to set the 2x6" joists rather quickly.  My question is: Don, could you explain the setting of the far outer joist first as the way to progress?  I want to end up square from the start.  I was also considering pr cutting the joists to exact length (117"), should I avoid that?  I have yet to nail the beam into place or place the lag bolts.

Thank you in advance.  Hopefully this project will improve my very low skill level to a point where I can build a cabin on my Northern AZ land, so all framing tips are welcomed!

[NM_Shooter]

I'm sure Don will chime in... I followed his lead also.  

Cutting those two joists first and placing them allows you to get your 4 corners set perfectly square.  Just remember to plumb the joists when measuring for square.  

Tack a 1" shim or 1.5" shim or whatever consistent thickness stock on the ends of the two joists, and stretch a string from one side to the other, sort of how the rim joist will run.  Then just start laying joists, and remember to hold the end of the joist back from the string whatever your end shim thickness is.  

The shims will keep you from bumping the string out as you go.  Floating it off the end keeps it from getting pushed around.

Remember that the second joists in from the ends center on exactly 16" (or 12 or 24) from the outside end of your beams.  All others center up on that 12/16/24 measurement.  

I'm sure you have this already, but be sure to remember the thickness of your rim joists when cutting your floor joists to length     117" is correct for a 10' width.

[soomb]

NM,
thanks for the tips.  You brought to light some very good tips for me.

Craig

[NM_Shooter]

Couple of other quick things...

1)  Make sure that those two end joists are as straight as possible.  You really want the corners as perfectly placed as you can get them.

2)  I mentioned to make them as plumb as possible too.  I nailed some alignment boards attached to the beams... these alignment boards are plumb and attach to the joists and the beams.  You can use them to lever the joist around a little too.  I placed the end joists, then screwed a couple of boards to the beams that allowed me to temporarily attach the joists to the beams using clamps.  (did this make sense?  Think of 4 alignment posts sticking straght up at the corners that hold the end joists plumb.) http://countryplans.com/smf/index.php?topic=4782.msg94723#msg94723

3)  The simpson clips that are diamond shaped work real well for helping to get everything lined up on the beams as you lay out the joist locations. 

4)  I hate to admit this, but I cheated on the blocking.  I've found that I can't just use calculations and get everything lined up.  I set the blocking in the joists as I was laying the first row of floor sheeting to make sure that I got the best placing of the floor sheeting on the center of the top of the joists.  I don't fully understand why this was, I suspect that not all 1.5" thick material is 1.5" thick, and some of the joists were twisted too.  As I was laying the sheeting, I would use large pipe clamps to pull / push the joists into position (some were mildly bowed).  This takes a little longer, but everything is lined up right on the joists.  I'm no pro.  I had to cheat a lot of stuff to make it strong / straight.  I used the heck out of all my clamps...I especially like the 4' long pipe clamps.  BTW... I found that a manual post hole digger makes a great tool for twisting joists and studs while you are nailing.  A 13 year old kid can easily put enough twist on a board while you nail 

5)  Remember to put the crown side up on the joists. 

[MountainDon]

My question is: Don, could you explain the setting of the far outer joist first as the way to progress?  I want to end up square from the start.  I was also considering pr cutting the joists to exact length (117"), should I avoid that?  

Well, here's how I did it, not to say it's the right or the only way.  Let me start by stating my beams were not absolutely parallel because of a couple rocks run into during the digging of the last few posts. In the photo the left beam was the first and what I base all references off.  I made the beams overly long to allow for adjustments. There was going to be some waste anyway in order to get the beam 2x joints to fall over the posts, so it made sense to me to trim them later.

I did precut my joists to their finish length which was calculated to take the rim joists into account as frank mentioned.

The nearest joist was place first. I used a Simpson H1 on each beam to hold the joist. I used a couple screws to hold and allow easy removal for adjustments. I placed the H1 on the left beam first, then placed the joist in it. We took some time to use the 3:4:5 method to get it set at a right angle to the left beam, then secured the other H1 with a couple screws.

Next we used a steel tape to measure along each beam to obtain the correct distance for the last joist at the other end. The beams were only out of parallel by a couple inches so I decided it was safe to ignore the slight error that would introduce. Don't sweat the small stuff, in this case I deem that small stuff.We measured along the top of the beam, not the top of the joists as that could introduce errors due to joist lean. I marked the top of the beams at the far end with pencil, then installed a couple H1's and dropped the last joist back in place. We double checked the two length measurements.  Note that I used a large pair of pliers to gently adjust the flanges that contact the sides of that end joist so they were tight but it was still possible to slide the joist.

I then set the first joist with equal overhangs over each beam. Close to a 1/4 inch or so. Again, don't sweat the small stuff. With that set and temporarily secured with a couple screws I firmly set a nail neat the end of the first and last joists. These were carefully measured to be set in one inch from the end of each joist. I used 16D finish nails and set them far enough in to ensure they would not easily move. I used a square to make them as close to vertical as possible.

We used a steel tape to measure the corner diagonals. Karen would hook the tape on the nail right down at the joist face. I pulled it very tight, Karen verified the nail did not shift. We were off several inches on the first run through. The joist at the far end was bumped along and the measurements repeated. And repeated. Repeated. Time to sweat the small stuff.    We got the diagonal to within 1/8 inch of each other. Running the a² + b² = c² equation (3:4:5) on the measurements proved the real world diagonal measurement. That last joist overhung the beams by slightly differing amounts due the the non parallel beams. However the difference was not large. If need be the first beam could be slide one way of the other to help with equalizing the overhangs.

I then nailed those H1's into place with the Simpson short nails, replacing the temporary screws with nails. Then measuring from the near joist I set the position for each subsequent joist. The center of the second joist was placed exactly 16" from the outside edge of the first joist. A nail placed temporarily in the beam was used to hook the steel tape on. Then the "16-32-48----" marls on the tape were used to mark the other joists. My method is to measure from the "left" side of that second joist. Then the 16" mark is the left side of the third joist. I make a mark line on the beam and place an X to the right of that line. The X is where the joist is placed. And so forth down the beam. The next to last joist will almost always end up with odd spacing to the last joist. Not a big deal. Don't sweat it. But after to layout the joist placement second beam if that distance is different by more than 1/8" something funky is going on. Check it out and correct before nailing anything more in place.

I then nailed H1's to hold the other joists. Frank is right on with the idea of the spacer blocks. For each side you need five blocks. At least that's what I used. Here's how. One block was temporarily nailed to the ends of the first and last joist. A string was tightly stretched and tied along each side over that block. My method on doing that is to pull the string around the corner and tie to a nail placed in the side face of the joist. That get the string tight against the spacer block. The string was placed close to the beam.

All the joists had been cut to length using a square as a guide for the circular saw. BTW, the saw was a Ryobi 18VDC model. It's light weight made to easier for me to handle, the thin kerf carbide tipped blade worked excellent. And my generator could take the afternoon off.

With the rest of the joists loosely place in their H1's I used the fifth spacer block to set the side to side position of the joists. As Frank mentioned using this spacer block method makes it much easier and more accurate to position the joists. I used the block and string on the south side when I set the joist and nailed in the first couple nails. Then I ran down the other side and verified that the block spacing worked out there as well. Maybe that was sweating small stuff?  If a block method is not used any one of the intermediate joists that is slightly out of place can/will throw off the subsequent joists.

I set all the joists before moving on to the blocking that runs down the center of my joists span. However, before settinmg the blocking I installed the rim joists. These also required a little up/down pry bar use to have their upper edge aligned with the ends of the joists. They lined up quite well as I selected and set aside some very straight 2x10's for that use.

I cut the blocking from some of the joists stock that I deemed not up to being used as a joists before installation. They are all exactly the same length, 14.5 inches to fit between the 16" joists centers. As Frank mentioned an adjustment tool is necessary. I used one of my 18" Bessey bar clamps to twist some of the joists into place. I snapped a chalk line down the center of the floor, across the joists. The blocking was nailed in place alternating on either side of that center line. I used a piece of 2x4 about 24 inches long as a gauge to level the top of the blocking with the upper surface of the joist. I used an air nailer; watch where you place your left hand if you hold the air nailer with your right.

Sometimes you may have to hammer the blocking piece into place, other times you will need a bar or pipe clamp to help pull the joists together. And frequently the "twisting tool" is required to get the nailing edges all together.

And as Frank mentioned joists go crown up. I eyeball them all while trimming to length. Then I place a X near one end, on the edge that goes up.

Hope that helps.  

[soomb]

Don,

That is an OUTSTANDING description and explanation.  I am building a 10 x 10 office as my first project and this will make things much easier.  at tip of the hat to all those on this site who take the time to help those of us who have great enthusiasm but lack the experience.

Craig

PS- I will try to set up a post for the 10 x 10 to not hijack this post.