View Full Version : water level
rat52
7th September 2007, 08:57 PM
A browse through hardware stores or catalogs always turns up a plethora (I love big words:D) of electronic and optical leveling devices. Although these are coming within reach, financially, of the handyman the simple water level and bubble level still have a place as low cost but accurate devices.
<!--[if !supportEmptyParas]--> <!--[endif]--><o></o>
I will assume that everyone knows how to use a bubble level :2tsup:and even strap it to a long straight edge to achieve a fair degree of accuracy but I still meet people who denigrate the water level as too old fashioned:? and are then amazed at the accuracy and ease of use (especially around corners) of my one man only water level, which I made more than 20yrs ago.
<!--[if !supportEmptyParas]--> <!--[endif]--><o></o>
I got the idea from a ceiling fixer who used a paint bucket for the reservoir but I made mine a sealed unit using 300mm of 150mm dia copper pipe and 2 taps. I also mixed toilet blue (can you still get this:rolleyes:) to make it easier to see and stop the water from going off and staining the tube (sanitized:cool:) .
<!--[if !supportEmptyParas]-->
To use, hang the reservoir at eye height then tape or clamp a stick to the hose end with the end of the stick on your datum (pin, pencil line, existing floor, etc) . With the 2 taps open wait for the water to settle then mark the stick. From then on raise or lower the stick until the water is lined up with the pencil mark and the other end of the stick is your datum, even around corners away from the reservoir.
<!--[if !supportEmptyParas]--> <!--[endif]--><o></o>
One caution,:no: don’t spill any water as this will alter the setting and you will have to re-calibrate the stick.
Another caution:no:, be careful outside on windy days as the wind blowing over the top causes a vacuum effect and will give incorrect readings.
dennford
7th September 2007, 09:15 PM
there are many variations on the water level and all are deadly accurate if used properly - well, what more level could you get than still water?
I generally use just a single hose and operate fom one reference line marking secondary lines at that same level. With this method it doesn't matter if you spill any water because you just lift the tube so that the new level lines up with your reference point and carry on duplicating that level.
When I built my present shed (I use water levels for all building), I marked my level and my niegbour (A tradesman!) kindly came around with his dumpy level to check/correct my levels: so I let him waste a while.
Denn
pawnhead
7th September 2007, 09:55 PM
I generally use just a single hose and operate fom one reference line marking secondary lines at that same level. With this method it doesn't matter if you spill any water because you just lift the tube so that the new level lines up with your reference point and carry on duplicating that level.You need two people to do that though.
You don't need a reservoir. You can just duct tape one end of the tube to your datum (or just nail it through the top of the tube above the water level), adjust the level until it's right (perhaps with an offset to your datum), then stick a bit of duct tape to your reading end to signify the level. Hold your finger over the end as you move around to ensure that you don't loose any water, and adjust the height to correspond with the duct tape on the tube. You can do it single handed, and you don't need to have a line of site to the datum. Of course you can tape it to a stick as well if your checking a ceiling or a floor somewhere away from the walls. Basically the same as suggested in the first post.
Or as mentioned, you can just stick one end in a bucket of water, under a brick, then you don't need duct tape. Just make sure that you've got roughly the same amount of empty tube above the water each time you make a new mark. And of course make sure that there's no air in the tube, especially where it comes up over the lip of the bucket. It's splitting hairs, but you should always make your marks at the meniscus (http://en.wikipedia.org/wiki/Meniscus) which will be noticeably concave on a narrow tube.
If you want a simple old masons' level, Just get a piece of straight 100x12x1200, rule a line down the centre, cut a hole near one end, drive a nail in the centre at the top, tie a string to it and tie a rock so it hangs where the hole is. Line up the string with the pencil mark and you've got a plumb level. For a horizontal level, use 3,4,5 to nail a cross member to the bottom. A bit stone aged, but certainly very accurate if you build it right. :wink:
I saw a good illustration of this on the website of a member here who calls himself billbeee: mason's level (http://www.builderbill-diy-help.com/string-line.html#Plumb_Bob). Interesting little story underneath that as well.
dennford
7th September 2007, 10:16 PM
I'll have a look after dinner.
Denn
notenoughtoys
8th September 2007, 12:09 AM
You don't need a reservoir. You can just duct tape one end of the tube to your datum (or just nail it through the top of the tube above the water level), adjust the level until it's right (perhaps with an offset to your datum), then stick a bit of duct tape to your reading end to signify the level. Hold your finger over the end as you move around to ensure that you don't loose any water, and adjust the height to correspond with the duct tape on the tube. You can do it single handed, and you don't need to have a line of site to the datum.
I used this method today to put the guttering up on my shed. 15yo son gave me a hand to do the job and once I showed him how to use a water level, he was as keen as mustard cos he then had "a job" :U
joe greiner
8th September 2007, 01:12 AM
When you move to a new target location, re-check the water level at the datum. Theoretically, the hose volume between locations should stay constant. 'Taint so, because of flexibility of the hose. BTDT.
Joe
pawnhead
8th September 2007, 01:52 AM
When you move to a new target location, re-check the water level at the datum. Theoretically, the hose volume between locations should stay constant. 'Taint so, because of flexibility of the hose. BTDT.
JoeYeh, I'd always close by re-checking the datum, then double checking all the marks. A bit like the old 'measure twice, cut once' adage.
billbeee
8th September 2007, 01:50 PM
Thanks for the plug John. :2tsup:
rat52, as soon as I read your opening paragraph I was reminded of a typical case of technological overkill. (how's that ? nearly as good as plethora).:U
We were forming and pouring about 4M high, tapered concrete blast walls in an electrical switch yard years ago. When we had the formwork for the first one set up, (with a plumb bob) the young engineer comes out and sets up his theodolite.
He took a couple of readings, we nudged the top over 3mm for him, he mumbled a bit, then made us push it back 3mm. Same at the other end. Then said we were OK to pour.
After that we always left them 10mm or so out, so that he felt he was doing his job.
Some things are constants: Water is always level, a suspended weight is always vertical, a 3,4,5 triangle always creates a rightangle. Why make things more complicated than than they need to be?
Cheers
Bill
dennford
8th September 2007, 02:12 PM
Thanks for the plug John. :2tsup:
Some things are constants: Water is always level, a suspended weight is always vertical, a 3,4,5 triangle always creates a rightangle. Why make things more complicated than than they need to be?
Cheers
Bill
Exactly, a laser level can project a straight line but if not set level then every point on that line is a different hieght - yet I never heard of sloping water.
Denn
Groggy
8th September 2007, 02:17 PM
.. yet I never heard of sloping water.
DennOh oh, here we go into the old "the world must be flat argument" :D
I agree with the points made, and will add that if you are aware of the basic principles, and keep to them, a laser still has its place. Especially for speed and sometimes in awkward areas.
As an aside, what happens with the water level when it is setup in the morning, then the full sun hits it?
pawnhead
8th September 2007, 05:03 PM
That's another point against a dumpy. A water level is obviously superior since it compensates for the Earths' curvature across your building site. :wink: I read somewhere that that it actually comes into play with some reeeeeeeeeeally long buildings.:q
I never heard of sloping water.I think that Irish water skier is still searching for some. :)
dennford
8th September 2007, 11:43 PM
Oh oh, here we go into the old "the world must be flat argument" :D
a laser still has its place. As an aside, what happens with the water level when it is setup in the morning, then the full sun hits it?
Yes a laser certainly does have its place in fact I believe that it is one of the most effective new age tools available - don't get me wrong when I tout the advantages of old methods I still embrace and appreciate the benefits of modern technology. However wether it is space age or stone age technology if we don't use it correctly then it will do us wrong.
Oh! and as for the expanding water in you next point. I thought that it was agreed that when using the water level as with any measuring tool we are continually rechecking our reference point - so expanding water is treated exactly the same as if we had spilled some water from the tube.
It's all a bit like navigation; everyone should be able to use a g.p.s. but I really respect and believe that a navigator tht can use a sextant,clock and compass is a much more accomplished person.
Denn
Skew ChiDAMN!!
9th September 2007, 12:05 AM
I like water-levels when I want two widely seperated datum points or am "walking the wall." (ie checking that an existing structure is level by walking along it with one end of the level.) They're cheap, quick'n'easy to set up, don't need batteries and you can throw 'em off a scaffold or run over 'em with a wheelbarrow without worrying about damage.
They'll also work in places where a laser can't be set up... if your datum points are on both sides of a wall, for example. They can be awkward to use in a one-man operation though.
Now the laser, on the other hand, will provide a straight-line reference between your datum points, doing away with the need for a straightedge, and is ideal for non-level applications. You want a 2" fall over such'n'such width? Simply adjust the laser until you get the fall. No mucking around with two marks on the level and then marking up (or down) 2" on one of them. I heartily recommend their use when screeding a floor. Takes a while to get it set up just right, but once it is you can see any highpoints.
They can be aright PITA to set up though, are useless in applications where you can't find a position with line of site to where the datum points need to be, don't take kindly to hard knocks and aren't the sort of thing I'd leave lying around in plain sight in the back of the ute or on any of the construction sites I've worked. :rolleyes:
So:Both methods have their advantages. Both have their disadvantages. Both have their place in my toolbox. :p
powderpost
9th September 2007, 11:23 PM
Question.......
Are two freely suspended plumb bobs truely parallel?
Jim
pawnhead
10th September 2007, 12:00 AM
Is that a trick question? If so, then the answer is no, but the closer they get to each other, the closer they are to being parallel. They point exactly towards the centre of mass of the Earth.
Massive plumb bobs are used to align skyscrapers during construction.
The CN Tower, located in Toronto, Ontario, Canada, is the world's tallest freestanding structure on land, standing 553.33 meters
Through the pour, the vertical accuracy of the tower was maintained by comparing the slip form's location to massive plumb bobs hanging from it, observed by small telescopes from the ground.
http://www.answers.com/topic/cn-towerThat article will soon need correction (http://www.woodworkforums.ubeaut.com.au/showthread.php?t=53082&highlight=dubai).
edit:
2007.sept.03 Burj Dubai is on the way to become the world's tallest freestanding structure. At 545.7 m (148 levels), it is just 7 m shorter than the CN Tower in Toronto.
http://www.burjdubaiskyscraper.com/index.htmlIt's probably passed it by now since it's going up at about a floor a day.
That's a bit of a milestone.
dennford
10th September 2007, 12:05 AM
trick question - some finer point that we can't think of ?
dennford
10th September 2007, 12:10 AM
example a plumb bob suspended from a 100 ft tower in London would be 163 degees to a plumb bob suspended from a hundred foot tower in Tokyo.
Denn
joe greiner
10th September 2007, 01:40 AM
Works at shorter distances, too. For example, suspension bridge towers can be far enough apart to justify accounting, when fabricating the deck truss and estimating the amount of wire needed for the job.
Joe
Barry Hicks
10th September 2007, 05:41 AM
Using water to find a level is not really a new concept. The ancient Egyptians used the idea when building the pyramids and probably borrowed the idea from an older civilization.
Barry Hicks
pawnhead
10th September 2007, 03:01 PM
That's an interesting subject. Do you know how they did it specifically? Any links to read?
I suppose they could dig a long trench for water (or use clay pipes, or half-pipes), or just dig a short one and drive two sticks in it for a line of sight to use sort of like a dumpy level. :?
I suppose you could make a crude dumpy level using a short piece of water level as your sighting reference. It's amazing how accurate your eye can be over quite long distances, even when your reference distance is comparatively short.
Barry Hicks
10th September 2007, 03:45 PM
PH, I'm not sure how the pyramid builders did it but I seem to recall (from some TV documentary) they cut a channel in the stone and achieved accuracy to within 5-6mm overall.
Some of our smarter forumites may have more accurate info.
Barry Hicks
HappyHammer
10th September 2007, 04:10 PM
As a non-smart forumite can I just confirm the following....
If I am building a freestanding deck roughly 10m x 10m and I want to mark a point on the corner posts, I can use a 15m clear tube with water in it to ensure marks on both posts are level to enable me to cut the posts to the same height for instance?
No smart answers about irrelevant tollerances required:q
HH.
Barry Hicks
10th September 2007, 04:20 PM
Yes HH, it is simple and accurate. I once re-stumped (and raised) a high blocked house using water to get levels. I was too mean to buy a great length of clear plastic tube but settled for the garden hose with a metre of clear stuff at each end.
I don't know how accurate it was but all the doors and windows worked OK afterwards so it can't have been too bad.
Barry Hicks
dennford
10th September 2007, 04:22 PM
that's exactly it mark your line on the first post and fasten your tube to the second at the approximate hieght. take the other end of the tube to your first mark and raise or lower the tube untill the water level coicides exactly with the mark - if you have no one to hld it then tape it at this level, where the level is at the other end is your second level (I always recheck the first end again (akin to measure twice).
Denn
rat52
10th September 2007, 04:29 PM
Barry,
the only problem with using garden hose is that you can't have any air bubbles in the tube and clear hose makes it easier to see them.
I think the air can compress or a bubble escape without you noticing and you get wrong readings.
These are the reasons I was given but I do know that bubbles do make a difference in the accuracy.
dennford
10th September 2007, 04:59 PM
Barry,
the only problem with using garden hose is that you can't have any air bubbles in the tube and clear hose makes it easier to see them.
I think the air can compress or a bubble escape without you noticing and you get wrong readings.
These are the reasons I was given but I do know that bubbles do make a difference in the accuracy.
Sorrry, I hadn't taken notice of the garden hose bit. Rat is very much right on that. Thanks Rat
Denn
pawnhead
10th September 2007, 05:10 PM
As a non-smart forumite can I just confirm the following....
If I am building a freestanding deck roughly 10m x 10m and I want to mark a point on the corner posts, I can use a 15m clear tube with water in it to ensure marks on both posts are level to enable me to cut the posts to the same height for instance?
No smart answers about irrelevant tollerances required:q
HH.This thread may be of interest:
http://www.woodworkforums.ubeaut.com.au/showthread.php?t=44361
Barry Hicks
10th September 2007, 06:08 PM
You are right about the bubbles. The only difference with using garden hose is that you can't see them so 'de-bubbling' become an automatic thing every time the level was used.
And yes, bubbles in the line certainly do give wild readings. I was fortunate in that I had an old chippie mate look in regularly to keep me pointed in the right direction.
Barry Hicks
pharmaboy2
11th September 2007, 10:54 AM
hi guys - getting a big enough bubble into the line is no mean feat. The only way it can be a problem if you succeed isif the line is coiled and you allow the buuble (has to be a decent size) to get to the highest point in the pipe ie above datum, then that will be the new height reading given.
I have used clear pipe always, and really cant remember making a mistake, but i always use a bucket at one end - the extra volume of water in a bucket makes sure that a small spillage out the end, essentialy makes no difference as it doesnt change the level in a bucket - much better than the small amount of water in a hose where 10mls might have reasonable catastrophic consequences to your heights.
I was using one once, and young carpenter came up, and said "mate, get yourself a dumpy - water bubbles can stuff you up in a moment!" - I asked him politely to empty the line, then refill it quickly with some bubbles in it - he declined the offer and took my word for it.
So, unless you think getting the whole coiled up hose, and pushing it into a bucket and trying top fill it that way is sensible, then you'll never have a partly filled hose. via tap or suction with siphon, never going to be a problem.
BobL
12th September 2007, 12:34 AM
Some things are constants:
a) - Water is always level,
b) - a suspended weight is always vertical,
c) - a 3,4,5 triangle always creates a rightangle.
Things are not as constant as they might seem :wink:
None of the above are correct
a) if the water is rotating
b) if a suspended weight is being accelerated
c) the triangle is not on a flat surface.
Cheers
pawnhead
12th September 2007, 01:47 AM
Things are not as constant as they might seem :wink:
None of the above are correct
a) if the water is rotating
b) if a suspended weight is being accelerated
c) the triangle is not on a flat surface.
CheersOr:
d) If you warp the space/time continuum, and open a vortex (http://www.geekologie.com/2007/02/largest_drain_hole_in_the_worl.php) to another dimension (http://www.artleaguehouston.org/Inversion.htm). :oo:
billbeee
12th September 2007, 08:11 AM
I of course know that sometimes water is not always level, I've surfed mast high waves in Lancelin.
I have observed no less than six Foucault Pendulums in various science museums around the world, so I did know that suspended weights are not always plumb.
And yes, I have observed that with a few large home made squares that I have made from time to time we had to make sure they were flat otherwise they were not always square.
So why the hell did I make those silly statements? I can't understand it. I must be loosing my marbles. Thanks for the correction Bob, I'll try to lift my game.:2tsup:
Cheers
Bill
BobL
12th September 2007, 02:29 PM
I've surfed mast high waves in Lancelin. Awesome - I can't even stand up on a board!
I have observed no less than six Foucault Pendulums in various science museums around the world, That's 4 more than me!
And yes, I have observed that with a few large home made squares that I have made from time to time we had to make sure they were flat otherwise they were not always square. thats' very fortunate indeed.
Cheers
forunna
14th September 2007, 01:48 AM
If you use the long clear tube method, dont pour a bit of red cordial into one end as an afterthoguht. It is heavier than the clean water at the other end. :-(
of course this is jsut theoretical, I wouldnt ever do that. :-