Laser levels

[Dan Hartung]

Another barn question. I have a two-story city barn with a sagging wall, and I would like to first determine the amount of sag, the amount of tilt, and any other out-of-square, out-of-level conditions, before proceeding with any remediation. Ultimately this may include replacement of corner posts, sill plates, and repair of a foundation. I'd like to do as much of this work myself as possible.

From reviews such as Amazon, I find that the consumer-priced laser levels are said useful mainly for things like shelving, as they project a line on a flat surface.

I would like to use a laser level for this job, but would it help? Would I have to buy a pro tool that costs hundreds of dollars to be of use? Am I stuck using squares, bubble levels, plumb bobs, chalk lines, and other tools?

[Pop Rivet]

I've got one of the cheapies, but I don't see how I'd use it for a large wall. First off, one wouldn't be enough, the cheapies lasers are good, but ... the mechanics of the use elude me for a wall. I tried to use it to level a mobil home shed I have and ended up putting some clear tubing in the ends of a garden hose and using that. Even with a tripod for the laser, I couldn't keep the tripod level enough to get a good line. Personally, I'd stock up on a few plumb bobs and a lot of tough string (kevlar type) so you could lay the whole thbing out at once and then just keedp truing until the wall comes into plumb.

But, I'm a complete novice, too, so ... FWIW!

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[Greg]

I have one of those $20 Harbor Fright lasers and it is a toy. You still need another level to set up the straight line feature (the clip on) and if you don't shoot it absolutely level from laser to the wall it will "belly". The beam is too weak to use outside. If you are just putting up pictures or shelves it can work but not any better than a yardstick and some string. If you are laying out a foundation or grading your yard use a hose and water.

[Robert Barr]

Have you searched for any similar projects on Usenet? Not too long ago I saw a website detailing some guy's efforts at restoring a really out - of - square building. Pretty interesting approach. Not that you'd have to use his techniques, but it could plant some fresh ideas.

With the geometry involved here, I'd be tempted to pick up a used surveyor's theodolite. Sell it when you're done.

Why bother with lasers at all? You'll still need to measure distances manually, either way.

I have one of those 'Strait Line' lasers, and on the package, they mention "Accuracy: +/- 1/2" at 20 feet". 1 part in 40. Now THAT'S impressive! Extrapolated over the kind of distances you're working with, and you could match that precision by throwing darts!

With the kind of expenses you're looking at, you want precision. I know which way I'd go: I'd pick up good used equipment, and sell it afterward. Consider any difference as the equivalent of rent on the gear.

Sounds like a fun project, except for the expenses...

Dan Hartung wrote:

[Dan Hartung]

Yeah, there's quite a few barn restorations on the web (fewer with pictures, alas). The tricky part is bracing for corner post replacement. If you have any more hints on that article, though ...

That's a great idea. My dad actually happens to have one (historic collectible, not sure I'd want to use it for this, nor do I know if it's

100% working).

Bleagh! Well, that's the kind of thing I'm finding. Very disappointing. The hype suggests they're so good they do your laundry too.

Yeah, it's a challenge ... I wish we had the money to do it right, but I've been around historic preservationists all my life, and I've seen buildings almost as bad get turned into swank living spaces. In some cases, though, it took decades!

(My favorite would have to be the old farmhouse out in the country that was being restored sort of one room at a time. The sophisticated owners had a wine party that was elegant except for the plastic sheeting defining the bathroom, and the room with no floor, marked off only with string. In those days caution tape hadn't been invented ...)

[Chris Lewis]

According to Dan Hartung :

1/2" at 20 feet isn't 1 part in 40. It's 1 part in 480 ;-)

Lee Valley occasionally sells an inexpensive laser level (when they get a shipment of them, for about $23 CDN) and they've tested it and found it to be 1/4" in 100'.

I have one, and tho I haven't used it much, I believe it.

It's really a matter of how accurate the bubble is and how well you read it. It's not as if laser light bends much (unless you have a black hole handy ;-)... If you can calibrate it or slave it off a better level (like a tested-and-known-good four footer), it would do just about as good as anything else possibly could. Within range of the spot of course.

[R Barr]

Yeah, I really blew that one. I need more fingers to calculate with...

Is it threaded for a tripod? Just curious.

Still, a decent theodolite, positioned at the exact center of the building, could tell you a lot more about the geometry than a level could.

[Murray Peterson]

Dan Hartung wrote in news: [e-mail]:

A laser level is wonderful for "drawing" a straight line over a distance, and you can then use that line as a reference point anywhere. Be sure to buy a unit that draws a plane (or "sheet") of light, not just a circular beam. Something like this one:

For measuring absolute level over a large distance, buy a water level:

Use the water level to mark some perfectly level endpoints, and then use the laser to draw a perfectly straight line between those two points. You can then use a tape measure to see how far your walls or floors are out of true.

[Chris Lewis]

According to R Barr :

I think so. If not, you could always duct tape it to something with a hole in it, and bolt it to a tripod. With some calibration checking, it'd work.

A decent theodolite would do the trick of course. But one would usually not be cost effective for just one or two jobs. Whereas, a laser level has somewhat more flexibility/use, vastly cheaper, and with a little ingenuity/perserverance would probably do about as well.

I figure for less than the cost of renting a theodolite, you get something to keep and use for other things too...

Not something a pro would want to screw around with, but...

[Amuzed2death]

Here's a cool water level that gives you a bit of sophistication. Maybe not laser sophistication, but easier to use and a whole lot more accurate.

I used this grading my patio (pavers) and I was amazed at how accurate the tool was and how perfectly graded the site ended up being. I improvised a bit, taping the working end of the tube onto a stick (making sure it could still slide a little, inside the tape). I marked level on the stick and then marked it in quarter inch increments up the stick, to easily establish and check grade. For every foot, I would line the water level a quarter inch higher. Worked quick, easy and accurate.

It won't work for sagging walls, but certainly helps for measuring level (not plumb) over longer distances.

[Murray Peterson]

[e-mail] (Amuzed2death) wrote in news: [e-mail]:

Nice for working alone -- I might buy one of those.

Unless you use them on a daily basis, you don't need the fancy featured laser levels. High accuracy, auto levelling and rotating laser levels are very nice (and expensive), but the only time it's worthwhile is if you are a contractor and time = money. Joe Homeowner can get the same accuracy with a water level and a cheap laser level -- they just take a few more minutes to set up.

[MC]

I bought a laser level from home depot about four years ago ?

Anyway, setup one of those above group 25' pools. Used the square paver stones as a base for each post section installed set on very stable dug not filled dirt. I used a few of the pavers stacked as a platform for the laser level as I did not have a tripos at the time. Took a very acurate regular level, checked the pavers for level from corner to corner. Then moving the laser level horizontally took a ruler an measured each of the base pavers for hight took the lowest one and dug out to level all other to this hight, used a regular level to level each from corner to corner. Also setup this same jig from opposite direction just to make sure all is same hieght.

The results when finished the pool, I was expecting to still be off maybe at best 1/8 of and inch.

Wehen we were filling the pool we used a water source that had a high rate of flow (two inch line from a deep well used for irrigateion at 75 gal/min rate.

We ended up not realizing how quick the pool would fill, was not apying attention and over filled to the rim!

When we shut off the water we noticed that the eater was beading perfectly around the entire diameter of the pool at the rim. I was amased at how level from one side to the other it was and that also must mean very good tolorences in the materials used in the pool.

At first thought would be overkill to use the laser level, was going to use the old string level method but wanted to play with the toy. I glad I did and I do not call it a toy anymore, Use it all the time now!

[Wayne]

"MC" wrote in news:BphQc.7819$Ns.1909 @bignews5.bellsouth.net:

You don't know whether you bought it?

Congratulations! Good job!

[MC]

Just can not remember exact yearI bought it, not if I bought it. I did notice all the spelling mistakes but spell checker is broke and was in a hurry, Sorry.

I was always one to take after dear old dad and do things the old fashion way most of the times, seemed to work and did not want to spend a lot of money on all the new gadgets.

But I have really go a lot of use out of that laser level.

However I have made one mistake on these gadgets. I bought one of those lasers that put the line on the wall, hang pictures, etc. I knew better but went right out of the box to using it. Several pictures was looking kinda uneven after using it. I got a standard level out and was off a good 1/4 inch on a big picture. Did several tests and found the build in level was way off, no way to adjust. I ended up making new marks on each side to use depending on with way the level was orientated and works so far. I will always take something out of a box and try it out before I buy next time.

MC

[Wayne]

"MC" wrote in news:7PBQc.2290$ [e-mail]:

I was just ribbing you.

I've learned the hard way on more than one occasion. I try to remember to check something out in the store, but not always. :-(

I have to say again, great job on the pool! I don't think I could have done it myself.

[MC]

I had helped setup a few of the smaller around 18 foot diameter pools for a few freinds before, Thought that a 25 footer couln't be too much worse, Boy was I wrong, It was a bigger job than I wanted to do.

Never again !