GETING THE HOUSE SQUARE

[eighthdoctor]

Hi
One of the things that I am worried about is getting the house square to begin with any videos or detailed web sites that do this for dummies I know this is basic but it is the starting point that every thing is built on we are doing the 1 1/2 story cottage with the pier and beam foundation we are going to lengthen It to 40' and keep the 20' width

[UK4X4]

3-4-5 ft to make triangles that are right angles any multiple of these numbers work

ie 6-8-10 so you can make a huge  "square" for layout

Then measure the diagonals- they should be the same..if they are not your making a Rombus house

[Squirl]

two words

Batter boards.

I preferred to use 2x2s for the posts with 1x3s for the cross boards.



You can use a right triangle calculator to find the cross angle.  A^2+B^2=C^2.
http://www.csgnetwork.com/righttricalc.html

A 20x30 has a cross diagonal of 36ft 3/4 inches.



A water level is best over long distances.

[alex trent]

When it is all said and done, the house will be square when the diagonals are equal.  That takes a bit of time but is not that difficult.

1. Lay the house out so the four sides are the distance you want them (a rectangle, I presume). Eyeball it as best you can.
2. Run a tape from one corner to the opposite corner.
3. If you only have one tape, note the distance to the inch.
4. Then measure the other corner to corner and note that distance. Adjust the sides to make the diagonal equal.  Takes a bunch of back and forth.
5. If you have two tapes, adjust the sides until they are equal. Same result as ## but easier with two tapes.

# 4 and 5 are easier said than done because as you adjust one side, you also have to make a corresponding adjustment on the other side to keep the distances along the sides equal.  but with some trial and error you can figure out which side needs to move in what direction.  I am not really good at this visualization, but I had someone who was, so when the diagonal was off 6", she know what had to move to get it square and also keep the side equal.  A piece of paper and a pencil to draw it out really helps.  You keep messing with it until the diagonal are equal and the lengths of the opposing sides are also equal. If your diagonal is off by a foot, you move both sides to keep them the same  and if you get closer on the diagonal, do more...if father off on the diagonal, move the other way. Pretty soon you will hit it.

Then you put in your corner stakes. Measure again.

Then you put in the batter boards, which have nothing to do with getting the diagonals correct or the house square, but allow you to work in the corners while maintaining you hard fought fix on the exact corner.

[Squirl]

Then you put in the batter boards, which have nothing to do with getting the diagonals correct or the house square, but allow you to work in the corners while maintaining you hard fought fix on the exact corner.

Batter boards are traditionally used to find the exact corners. Depending upon the slope of the land with high spots and low spots, to get a level even measurement batter boards are set up and leveled with a water level.  This way when you are finding diagonals, they are even and level.  Even on mildly sloped terrain over a 30-40 foot distance without measuring from a level surface, it can put your corners off up to a couple of inches.

[alex trent]

Squirl makes a good point...you need to measure on the horizontal, not following the slope of the land on the diagonals as with a slope that will be off...longer where you have a sloped side/diagonal. You could use a water level but on a short run like you have  using a level on the tape or a line  works fine if you do not want to do that and you will be every bit as accurate if you do it carefully.  You can put in a temporary corner post, marked with the level spot...you'll have to have one ready anyway to set when you get the diagonal figured. as you need to be. But what he says about batter boards is confusing. Yes you need them. But the batter boards are done after the corners are accurately set.....they only define where the corners are set so you can work at the corner and still know where it is. They really have nothing to do with finding the diagonal...in fact you cannot set the boards until you have the corners defined. So, its the next step...do the diagonal correctly first and don't worry about the roof right then.

[Squirl]

Another nice thing is once you square one corner the other corner should be square just by finding the sides.

Say you measure a 20 ft and 40 ft sides.  The diagonal should be about 44 ft 8-5/8th inches.

Now just take the corner you measured square and with a 20 and 40 ft tape measure on each corner, where the two meet will be the fourth corner.  Of course, double check the fourth corner with the first.  Measure twice.

[alex trent]

HA..I measured 5 or 6 times...would wake up at night and wonder if I really squared it! And I confess, when we got to the finish, it was off 2 inches. Made it work, but was a simple design and mattered a lot less than in another type....like a two story!

[SouthernTier]

Any tips for setting up batter boards on a sloping lot (cabin will have a walk-out basement)?  I haven't come up with any options other than just really tall stakes on the downhill side.  And would need plumb bobs to set the corner stakes on the two downhill corners.

[alex trent]

Just speculating, not done by me on #1.

1.  You could extend the batter boards up to the top on the place where that would be level with the other set.  My problem with this is at more than a couple of feet elevation it gets to be a minor construction project and it knocked could be easily thrown out of line as they are tall and likely not all that firm.

2.  Do them at  a foot or so off the ground (like normal for flat ground), but align the strings to be where the top of the corner stakes are when they  are perpendicular to the ground (this means the ground level diagonal will not be the same as the real one). You can still run strings as you need them which is until you get the real posts/corners set. Takes a bit of jockeying, but seems to be a solution. My error came when I did not do a good job of adjusting the string intersections (diagonal corners) to were the top of the corner stake was when perpendicular...so I was off a couple of inches, even though I started out right with the correct and matching diagonals.

[flyingvan]

If you're going to have a basement, couldn't you dig that first with rough dimensions, then use the flat surface you've created to mark your corners more exact?  If the basement isn't under the entire house, just do that first then measure off that

[MushCreek]

The guy that did my excavation has a cool laser thingie that sets up square corners, among other things. My 33' X 44' foundation checks out within 1/4"- good enough for me. I'd hate to find out what that little gadget cost, though!

[flyingvan]

I bought a small version--it's a foot long bubble level with x,y,z tangent laser that's dead on.  I'd just mount it upside down on my camera tripod so one beam pointed at a corner and the other two went off at right angles.  It's only as accurate as the bubble level though.  I paid $80 for it.  Easiest to use at dawn or dusk
The mentioned above water level---you might already be familiar but here's mine---I paid a few bucks for some clear vinyl tubing, and it's as accurate as anything out there, no matter how expensive


   Just drive a few stakes near corners, fill the tubing with water (NO BUBBLES) and secure tubing to stakes.  Mark where the water is and take your measurements off that



   My foundation is exactly half the size of yours.  The trenches were close, so after building the forms I squared them up using 3-4-5 and screwed a crossbrace in across the corner to hold them in place

 

[Squirl]

A friend of mine owns an excavation company. 

I borrowed one of those fancy self leveling lasers with a grade stick for my excavation.  Those things cost in the thousands.

I would personally probably raise the line a few inches to get a measurement without dips or high spots.  Then I would measure the elevation between the two points with a water level.  I would then plug in the values of the elevation and the distance needed into a right triangle calculator to get the distance of the measurement with the slope.

Say if I had a wall 30 ft long over an elevation change of 6 ft.  So when measuring at ground level the line would be 30 ft 7.08 inches.  It can even be used for the diagonal measurements.  It should get you within .5 to 1 inch of square.  That would be good for the excavation and probably the footing.  The walls can usually be adjusted over the footings.

That Pythagoras was sure onto something.

[SouthernTier]

If you're going to have a basement, couldn't you dig that first with rough dimensions, then use the flat surface you've created to mark your corners more exact?  If the basement isn't under the entire house, just do that first then measure off that

That would be one way.  However, while I plan to do just about all the building of my cabin myself, one of the few things I will sub out is the foundation excavation and construction (blocks, not poured since can't get a cement truck up there; also, it will be just half the cabin as you suspected, the rear half will just be crawl space).

But since this will be subbed, I would like to be able to be really really accurate where I want them to put the corners of footers.  But I suppose I could get close enough fudging it somewhat, and then tell them the dimensions I want.

Note, I did use a water level for setting the elevations of the sonotubes for the shed I have built first, also on sloping ground:



I handled getting the columns on square by doing some tall corner stakes and diagonal measurements, and then over-augering the hole so I had some leeway as to where I placed the tubes.  And then as a final measure, I made this jig (note, those aren't the sonotubes it is sitting on, those are just the tops I cut off after water-leveling):



which I squared using the diagonal cables with turnbuckles to get the final placement right.  However, I can easily pick up an place a 10x10 jig.  That would be much harder for my planned 22x26 cabin.

And it didn't really work all that well.  While the Simpson brackets for the beams were in the right place thanks to my jig, the tallest tube (yes, it is too tall, but it is rebarred and is sunk nearly 4' below ground so it isn't about to topple over) still ended up off-plumb in order to line up with the jig:



Being off plumb drives me crazy.  I am thinking of putting a deck there just so I don't have to look at it!

But the fact that that corner had the highest off-the-ground corner stake is why it ended up being off, and why I asked this question.

But the water level worked great.  The floor was quite level.

[SouthernTier]

I would personally probably raise the line a few inches to get a measurement without dips or high spots.  Then I would measure the elevation between the two points with a water level.  I would then plug in the values of the elevation and the distance needed into a right triangle calculator to get the distance of the measurement with the slope.

Say if I had a wall 30 ft long over an elevation change of 6 ft.  So when measuring at ground level the line would be 30 ft 7.08 inches.  It can even be used for the diagonal measurements.  It should get you within .5 to 1 inch of square.  That would be good for the excavation and probably the footing.  The walls can usually be adjusted over the footings.

That Pythagoras was sure onto something.

I think I will try this.  Excellent idea.