Hey all-
I’m teaching a class to our apprentices about plumb, level and square. What is it you wish every carpenter knew about these things. What are some tips for using a laser? Which one is the best and for what? What do you use your laser for. What are some uses that someone has come up with that might be unconventional? Are those water level and laser products worth it when $3.50 worth of plastic hose does the same job?
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Replies
A self-leveling rotary laser is key for my projects, leveling and lifting houses. I used a water-level before and would only go back to it if forced to. The water-level theory is elegant and simple--each water surface will automatically be at the same elevation-- but much can go awry: spills change the calibration, algae grows in the water if in use for a length of time, there is friction in the line that impedes free movement of the water, air bubbles will add to this friction and can really mess up readings, and most importantly, it has to be moved from point to point to check and recheck each elevation. (People can step on the tube, it gets tangled in stuff when you need to pull it around...) The laser gives a level plane, continuously visible at every location needed, at least in theory. But it can't project through obstacles or around corners, so there can be "dead zones" where the beam is shadowed by posts or other items. Then there is a battery issue; I've been running mine from a cobbled-up AC transformer rather than keep changing the batteries a couple of times daily sometimes. Might be safe to say I'd keep a water-level for use on a remote project or when my laser is down, but otherwise...
I do interior framing with cf steal and use my little line laser all the time to plumb my track on the floor with the one on the ceiling. I wasn't sure at first if it would be worth the cost, now I,ve got it I love it, use it for everything. I havn't had to yet, but I would suggest that you check the level every once in a while to see if it needs to be callibrated. Hilti does it for free I think. My PLS costs me 20$ to callibrate at the store where I got it.
On another note. About 15 years ago I worked with a carpenter who would check square with his tape measure, take a few measurments from point to point or something. I'd love to remember how he did it. Perhaps its basic carpentry, is anyone able to share this mystifying technique.
On another note. About 15 years ago I worked with a carpenter who would check square with his tape measure, take a few measurments from point to point or something. I'd love to remember how he did it. Perhaps its basic carpentry, is anyone able to share this mystifying technique.
3-4-5 right triangle? With sides of 3 and 4 whatever (inches, feet, furlongs) the hypotenuse will be five. I lay out decks using this right triangle.
Another one is the 1-1-square root of 2 right triangle. With equal sides, the hypotenuse is the side times the square root of two, or about 1.4. So a right triangle with one foot on each side would have a diagonal (hypotenuse) of 1.4 feet.
Is this what he used?
"I am the master of my fate, I am the captain of my soul." Invictus, by Henley.
Edited 8/16/2006 7:02 pm ET by NickNukeEm
A 45° right triangle's hypotenuse equals one side x the square root of 2. 1.4 may be close enough or carry it out as far as your calculator can figure square roots. For some reason I can remember the square root of 2 easier than 1.41421…
No basic math. 3,4, 5 makes a right triangle multiples of that also is a right triangle 3 x 2 = 6, 4 x 2 = 8, 5 x 2 =10 so 6, 8,10 = right triangle also
There is also this Pythagorean theorem a, sq + b sq = c sq will give you a right triangle. A little more work.
It's the Pathagoran (sp.?) Theorem a2+b2 =c2. 3'x3' [=9] + 4'x4' [=16] [ 9+16=25]= 5'x5' [=25] If you want to know if a wall is square, measure 3' one direction from the corner, 4' from the other, and the diagonal between the two points should be 5'
Thanks guys, thats perfect. I love square rooms, but rarely see them. I also install drywall, (hence the name), that stuff just jumps right out at you if it's off square or out of plumb. It seems to be a mistery to many, or people just don't care. "No one will see that."
A small point of clarification.
Doing a 3-4-5 where you are actually measuring 3' and 4' sides and a 5' diagonal will only tell you if the very small corner you measured is square. Better to go for a 9'-12'-15' so that you have a bigger sample if you're looking at a room.
But doing so at one corner only tells you about that corner, not the others. The room will only be square if the diagonals between equal lengths of plate are also equal.
Getting them into the habit of checking for plumb, line and level at appropriate times - i.e. before everything gets pinned down and nailed together - will save their bosses time and money.
Getting them into the habit of keeping eyes open - even when relying on instruments - and their thinking cap on at all times, sure helps in the plumb, line and level depts.
Getting them into the habit of checking their squares and levels, and calibrating their lasers, will pay off in spades.
There have been some extended discussions in the past on Breaktime about the virtues and vices of the various lasers and water levels. A search of the archives using the appropriate search terms should give you enough to keep you occupied for several hours. One thing I remember was someone commenting that the water level gave them a false reading when one side was in the hot sun and the other was in a cool shaded area. Hot water being less dense then cold water, the water on the hot side will be some fraction of an inch higher than with the cold water.
I have one of the older David White whirly gig lasters that takes forever to try to get level. The line it projects is a bit weak in bright areas. I also have an older I-beam style level/laser that has a really strong beam that will project for over 500 feet after dusk - of course the spot at that distance is about six inches in diameter...
the Pythagorean theorem is A squared +b squared = c squared. but i find most poeple dont understand its proper use. 345 is the same thing but if you have a 30 ft wall butting into a 80 ft wall, this is too small a triangle to work with. the advantage of pythag is you can make points any where along the line. eg... getting the 30' point correct is great, but your wall might be curved. using pythag you can set as many points along that 30' line as you want to insure a straight wall. same as you can use it to square something 6" long too. also the equasion can be used for plumb.
as for lasers. i like and use the 5 way laser alot. up, down, front, both sides. i find sometimes you have to improvise for it to be a help. eg... i like to layout pot lights on the floor first then shoot the marks to the ceiling. if i measure off one wall chalk a straight line then set a box or object at one end of the line putting the corner of the box on the line, the laser at the other, shoot one line onto the box corner the laser will give me perfect square. i lay out the room, mark my pot locations, then laser them to the ceiling. perfect straight rows every time. they are great for fence post layout, outlet box layout, tansfering marks around or up a building, leveling over long distances, plumbing up tall items, they are magnetic so they attatch to steel stud or steel columns. you just have to think and improvise and it will do alot more than you realize.
hope this was help
Tmaxxx
Urban Workshop Ltd
Vancouver B.C.
cheers. Ill buy.
Apprentices??? You've got apprentices!!!??? I thought that was an extinct concept!! :)
I would stress to your apprentices what Pierre1 stressed on:
"But doing so at one corner only tells you about that corner, not the others. The room will only be square if the diagonals between equal lengths of plate are also equal."
You can have equal diagnals and still not have a square room. An example would be if your room looked like this:
Teach them not to assume anything is plumb, level or square, especially if they are remodeling, but also in new construction. Always check before beginning a new phase of the project. In new construction, how many times have you seen a foundation out of level, plumb and/or square? Or a wall? And maybe it's not straight, either! (Those dang subs! Hey wait a second, I did that!!) How about hanging flush-mount upper cabinets to a ceiling that's not level? Or at a corner that's not square? It's enough to drive a guy nutz! And thats new construction!!
My background is primarily in remodeling, and I learned early on to assume nothing is plumb, level or square (or straight). It's nice when it is, but unusual in my experience.
Also, kudos to tmaxxx regarding the Pythagorean theorem. Thinking 345 is handy but too limiting. You have to remain flexible in your thinking. A squared + B squared = C squared is much more useful, even if it takes a little more time. Also, remember when using it one needs be mindful of which edge of the tape you are measuring along. It only works properly if the lines you are measuring along are of infinite thinness, so be sure to use the same edge of the tape.
One last thing: education is only good when it takes, so it is ultimately up to your students to make use of what you have to offer. And good on you for teaching them!
Lot of good advise, especially from the mathematicians. I would make sure that the students learned " old ways" first. When the high tech fails, nothing works as well like thinking on your feet. I once was trying to plumb a two story wall in a high wind, my father came along and said " take that plumb bob off and use a 3 pound sinker".
I
Sawduster - Years ago an older carp showed me something similar. He used a pocket weight from an old style double hung window. Made for a great heavy plumb bob.
Then he had it land in a 5 gallon bucket of water. Water acted as a dampener against the wind. "Old tech" simple and works really well...Buic
I use a five-beam laser to mark plumb for balusters on curved stairs, also use it to make sure the chassis isn't too far out of whack on the old race car after a crash. Jim Devier
That is an excellent idea! I have been building for 12 yrs now and have never seen that. So simple!
Thanks for the great tips everyone, keep 'em coming. I have until August 30th to prepare for this class. What is everyone's favorite brand of laser, there is a lot to choose from. Which would you recommend for a first time purchase? Does anyone use a transit or builders level anymore?
JCM
Let me preface this comment by saying that it is not in any way meant to be sarcastic.
It's a little surprising that someone who is asking such basic and wide ranging questions is the one who will be teaching a class.
I think your enthusiasm and willingness to do it is great.
And you're filling an important need. These basic concepts are a part of a carpenters' work for life.
A little more about the class and your background might help get you more of the information you need.
Is this mainly for exterior or interior work?
Rough or finish?
Residential or commercial? (that you have a class of apprentices makes me wonder.)
- The laser you use for a wall layout might not be of much use for tile.
They should understand the relationship between plumb, level, and square and be able to apply it to whatever they are doing.
Levels, bobs, lasers, water levels, squares all work.
How you use them often makes the difference.
If you have some specific applications in mind posting them will make it easier to answer you...Buic
Right on.
I believe that the difference between a carpenter who can be a lead carpenter and all the rest is that the lead knows his high school geometry.
Ron
Yeah, I stayed awake in math class.
Well, I have been a carpenter for about 12 yrs, in new construction and remodeling. From 1997 - 2002 worked in remodeling exclusively as a lead carpenter in the Seattle area. The economy went south here after Sept. 11 and the company I was with at the time went through some lay-offs. Spent the next couple of years as a framing sub working on all kinds of projects, everything from ground up small additions to framing and siding on million dollar homes. Now I find myself working as a superintendent on a 6 million dollar residential project. The company I work for has over 100 employees, and long ago they decided to hire based on work ethic, we can teach them the rest. The job market in Seattle right now is pretty tight and good carpenters are hard to find.
I have built some pretty cool buildings with nothing more than a plumb bob and a water level. Gravity doesn't lie. The only laser I had was a checkpoint torpedo. It required two people and the beam wasn't very bright. A lot of what I know is self-taught, or was something I read in Fine Homebuilding, so I am looking to get as much info as possible from as many people as possible. I was picked to teach these classes for my ability to teach and communicate complex ideas, as well as my experiences on the job. The tasks we require our guys to do are pretty wide ranging. Most of what we do is oversee sub-contracted work. There is still a lot of pickup on projects of this scale. We install all of our windows and doors, all the millwork and cabinets, and assist our subs when they are short on staff. Everything has to be to the gnats ####, our tolerance here is quite short.
Much of the feedback I have gotten from this post has all been stuff I knew. As many years as I have been building ( I know 12 isn't much, I'm 32), nobody showed me and I didn't think to use the bucket of water trick. So, honestly your tip has been the most helpful. Thanks.
"We install all of our windows and doors, all the millwork and cabinets"
If this is a large part of what they do, then consider this.
Any company of size will not have enough of everything for everyone at all times.(I've never seen it) Be sure they know how to do things more then one way.
For instance, you're about to install kitchen cabinets. You want to know where the high spot in the room is. If you have a line laser like a PLS 2, you'd just set it to shoot across the space and measure to the line as needed. Smallest # off the tape is your high point.
Without the laser could they do the layout? With only a 4' level, or a water level. Would the counter height of the island in the middle of the room match the base cabinets against the walls?
Teach them how to check their levels. Set it on any surface and mark where the ends are and read the bubble. Turn end for end and reset on the marks, bubble should read the same or the levels out. I do mine after every drop (it happens) or every week.
Keeping them in a case helps alot too.
Use braided fishing line on their plumb bobs so they don't spin as much and the thin line makes it easier to be accurate.
The new bobs with the self winding line in a case with a hook, steel pin, and magnet for attachment are worth the money.
For your water level, have 3 quarts of water and 1 quart of anti-freeze in a gallon jug. Siphon out of the jug to fill the level and you'll never fight with air bubbles. You'll also see the level more easily, it won't freeze on you, bacteria won't grow in it,and if you keep the jug and tubing together they'll be at the same temperature and work better. Drain the tubing back into the jug when your done.
There's alot more but my typing takes forever. If you want, e-mail me with your phone # and we could cover a lot of ground...Buic
>>"Does anyone use a transit or builders level anymore?
About 6 months ago I decided I needed a transit so I bought an old, used total station that came from a local college surveying class. To make a long story short, once I figured out how to use it and what it can do I now have a modern autolevel and a modern chinese made total station accurate to within less than an inch over a mile. I got so interested with it that I learned everything I could about surveying methods which are really just measuring bigger things, but it's all still about measuring.
In the process of learning the geometry and statistical methods used for surveying it changed the way I measure anything, even with a tape. I now measure geometric shapes rather than just dimensions to determine the fit of anything that has to go in a place that's not perfectly square or straight (which is just about everywhere). It's really been a new way of looking at things for me.
For your class, in squaring for example, I'd recommend you include basic geometric identities that describe what is "square." For example, if you need a line square to a spot on a wall plate for interior framing, you can use an angle bisect technique. Make two marks equal distant from the spot on the wall plate. Swing an arc of radius longer than "spot to mark" distance from each of those marks. Draw a line from spot to intersection of the arcs. You get a perfect 90 degree square line in a few seconds of careful work. Include everything you can about the geometry of triangles. It's a simple shape that most of the things we work with are composed of.
For most layouts, I use the total station to check it and I admit for the shorter distances I use the total station to shoot marks which I then run string lines from. Fast, easy and often fun.
Same thing for plumb -- optical plumb is PLUMB, period. Optical level is LEVEL, period. For grading I use a self-leveling laser. Faster and the slight loss of accuracy compared to the autolevel is negligible.
"Let's get crack-a-lackin" --- Adam Carolla
Great idea, Phila. Thanks for the input.
I've used many lasers that I thought were the best but today I purchased a Porter Cable self leveling laser that really works for my application.
I'm a deck builder and need to lay out many beam runs and calculate the the post height from the saddle of the pier block to the finished height of framing for each pier. Today I had eighteen piers to measure.
You set the self leveling devise on a tripod. Line the laser dot at the door , measure from the dot to the bottom of the door jam, add the thickness of your decking and today that was 20".
Now add the thickness of the joist 2x8 (71/2") and beam 71/2"= 15".
now add 15" and 20"= (35") subtract this number from each pier measurement
Now the cool thing about the new laser I purchased is it has a remote. Each time I put my tape measurer on top of a pier I can push the arrow on the remote to bring the laser dot to each pier block without going back and forth to aim the laser at the pier from the tripod.
My first measurement is 38 3/4"minus 35"= a 3 3/4" block from pier saddle to bottom fo beam.
Next measurement is 43 1/8" minus 35"= an 8 1/8" block from pier saddle to bottom of beam.
This a a model LR1100 self leveling remote controlled laser level.
Hope this helps,
"Rather be a hammer than a nail"
Bob
I wuz in highrise commercial curtainwall work for a while, back before lasers were in use like they are now.
Saw the crews using plumbobs stretching over many stories, using small diameter braided wire cable for the line, huge steel or lead weights on the bottom, and dampened in 55g drums filled with water.
Then he had it land in a 5 gallon bucket of water. Water acted as a dampener against the wind.
I like this, ...old school practical thinking!
My neighbor an old plumber, pipefitter in his 80's and retired told me about the plumb bob trick. He used a metal coffee can though.
I gave it a shot and it worked very good. I know you don't owe me but I wish you'd let me, ask one favor from you.
I use the 5 line laser to set up for wire shelving installations. I setup a block at the right height for the shelving on the jamb of the closet and then place the laser on top of the block for a level line, then proceed to mark the wall at 12" increments. Mark the ends and move on. Then I go back and drill and install all at one time. Works really well for walk in closets as the line can be shone on all walls . I originally got it when I had to do 80 shelves in a student residence (6 units) So my guy did all the shelves in 1 day - installation cost was 9.50 per shelf. Laser cost $ 170. Overall good deal Now I install as many shelves as I can for all my customers and it's one less contractor for them
I have also used it to layout wainscotting in a largish room
First we get good- then we get fast !
I'd like to see a $3.50 water level give me a plumb spot twenty feet down under my bearing point.
I haven't used a plumb bob for years since I got my laser. It is less important for newbies to know what kind since they won't be buying it. They do need to know how not to break it, and how to avoid knocking the stand over once it is set up.
They need to know some trig to do layouts square, starting with a basic 3-4-5
They need to know how to buy a basic four foot level. At least a third of the ones in the stores are not reading true on all bubbles. It is easy to test right in the store. I can remember once going to three hardware stores to find one good level.
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That's so right. I recommend and own only Stabila. And also, the apprentices who want to advance up the chain will be buying their own tools, we have a tool purchase program so they can do just that. Having your own stuff shows that you are serious about homebuilding as a career and not just "getting by for now."
J,
I've been doing kitchen cabinetry installs , trim carpentry, and renovation construction for some time. never went through any formal apprenticeship but had some great teachers along the way. The key to anything is understanding the concepts. Why is level and plumb important? When building upon existing things math only works when things offer no variations (ie- level and plumb).
First have them understand the difference between level and plumb. then review margins of error and how to minimize them. (multiple readings, flipping levels end for end to eliminate level inaccuracies, etc.). then review the basics of plumb bobs, water lines, hand levels (2',4', 8',plate levelers, etc.) then break out the lasers. lasers are excellent tools when cared for, when calibrated, and when the batteries are working. sometimes in a pinch one must revert back to the old standbys when the laser is not functioning or perhaps on another job.
explain how plumb and level projects make things progress smoothly start to finish from the plywood sheathing (which is square) to the cabinetry and trim.
nothing looks worse than tapered reveals between door trim and an out of plumb corner or a tapered reveal between the ceiling and the kitchen wall cabinets from an out of level ceiling. not to mention getting stairs to fit when the overal riser hight changes across the width of a set of wide stairs. perfection is not nescessary, but accuracy and being as close as one can matters. teach them well so we will hire them.
JASON
Level, plumb and square are great concepts and should be the rule when working, but remodeling takes on a different approach...sometimes its better to "skew" your work ever so slightly so that your work "blends" in with the existing surroundings.
Examples...if the floor has a slight slope or sag, its better to trim off the door bottom in the same manner . Cutting the door bottom off in a level (straight) cut will call more attention to the sloping floor angle. Window trim should be equi-distant from ceiling trim. If a window head casing is attached perfectly level, but the crown moulding above slopes with the ceiling contour, then things will look out of wack. Better to slightly skew the head casing so that the margins between the casing and the ceiling are equal.
Door jamb casings that abutt an adjoining wall need to be equi-distant from the wall if that whole wall is out of plumb. Tacking on a plumbed casing a few inches away from an out-of-plumb wall simply causes things to look bad.
Teach your apprentences about how to "split the difference" on measurements in order to slightly skew something so that as a whole, the end result won't look out of place.
Please go over the concept of using stringlines to check for straightness of wall studs, concrete formwork and the like. The simple string has many uses and should not be overlooked. Stringlines work well when installing suspended ceilings, or placing bolts in specific locations for concrete work, or when checking a door opening for crosslegs, or checking to see if joists and beams are in proper alignment.... etc. etc.
And .....my pet peeve...please teach your apprentices the proper terminology. My skin crawls everytime I see a guy holding a level in the vertical postion against a wall or jamb leg, and say "Yeah, its level!"
Davo
Preach on Brother Davo!
I absolutely agree. Good craftsman should always think on their feet. Each situation is different, and sometimes things should be adjusted for the benefit of appearance.