Love this man. It’s nice to see older guys try to get young guys involved in plumbing. It’s a great trade if you really take pride in your work because it really feels like art a lot of the time.
For all that's curious. He used 1.41 because that's the secant of theta 45 degrees..... If you have a different angle that needs to be made, use your calculator and type in that degree of angle you want then the (sec) button. The number you see you then multiply by your, "center to center" measurement.
If you don’t have the sec button, like on calculator in iPhones, then just input the angle and press cos. Then press m+ (make sure your memory is cleared by hitting mc). Then press 1, then press divide, then press mr which will recall the cosine of the angle you just input.
GREAT JOB!! As a union journeymen plumber in chicago who didnt take the whole 5 yrs to get state license i was taught the first 6 months of apprenticeship the formulas for all offsets. My instructor use to call ppl that eyeballed measurements clowns and would roast them. For the ppl that say you'd be fired for doing math obviously dont know how to do math because while your eyeballing fitting to fitting ive figured out every cut piece just by pulling measurements. But each their own i understand some may not be mathematically inclined but keep up the great videos mr. Wakefield im sure your helping alot of ppl
For an experienced plumbing contractor like myself, all you need is a tape measure and a good eye, no math required! Done it enough times over the last 35 years 👍
as a Plumbing contractor of 23 years, I just use the old school method, "eyeball it" I'm good enough at my profession to do that! have never used the formula since I took the plumbing test! great video non the less! All apprentices need to know how to do the math too! 😁👍
Right on, where you ever taught how to use the formulas? While eyeballing does work for most people...I think it's a good foundation that everyone at least knows the formulas
@@RogerWakefield I have always (or almost always ha) use the formula. I was taught to memorize what 1.4 times 2 through 9 is. 1.4 is close enough unless you are welding. That way, you can do the math in your head. If eyeballing it works for ya, more power to ya. Just know that the numbers don't lie.
Never got taught this, loved it! Stovepiping with the "magic eye" gives instantaneous measurements though, the foreman I trained under was like this. Crazy fast with dwv, his eye was so well trained he'd set up pipes or fittings without a torpedo and ask us to check it later. Always level or on mark. Would only see him pull a 2' foot level to set grade in ground. I'm not as good so thanks alot for showing us this video. Really appreciate the knowledge and insight, still hooked on stove piping but will start memorizing the percentage of 1/16ths and see if the noggin can keep pace.
Awesome, plumber here and I forgot how to do a 45 offset using 1.41. I’ll probably end up using it now to make those 45s crisp and less room for error. I’m used to eyeballing now but always trying to improve
I am old school and was taught math early on as well as marking locations and dropping a plumb line and snapping chalk lines. Then adding fittings and drilling hangers. To be a good plumber you need to spend about 4 years in all types of plumbing and then pick which one to stick with or do like we did and just do all of it
Okay, I can certainly apply the Pythagorean Theorem to calculate the length of the center to center offset for both. Let’s back up and refigure the two 45 degree ells first. We have to visualize a right triangle in the stud bay to visualize it. Go to 8:30 in the video and then superimpose the horizontal tape measure visually and you will see a triangle. That is a 45-45-90 right triangle and can even be drawn in the stud bay with pencil to make it easier to explain. We know the length of the tape measure side is 12”. We will call that side A and by definition the other leg of the triangle (which is mostly covered by 2” vertical PVC on the right that is about to be cut off) must also be 12”. There’s our A and B sides and the center to center length of the diagonal pipe (plus a bit of fitting on either end) is C, our hypotenuse. Apply the Theorem. A squared plus B squared equals C squared. 144” + 144” = 288”. C squared equals 288, so find the square root of 288 for the length of the diagonal, which is 16.97”. That is closer to 17 by a hair, but we could call it 16 31/32” to split the difference and be very close. Subtract off the 1 1/2” from both sides for the fitting and that pipe is cut a smidge shorter than 14”. Same result different paths. Go back to that same imaginary triangle to get our difference in height. That leg of the triangle is 12”. Add 1 1/2” fitting allowance on both sides to get an extra 3” and there is your 15” vertical difference. Figuring that part is tremendously easy now. To solve the problem of a two 22 1/2 degree fittings making the offset go back to 8:30 on the video. That 45 degree angle between the two pipes that form the bottom of the triangle is now bisected. What that does is the pipe travels half as far to the left in that 12” vertical, so the vertical leg must be doubled to bring the diagonal all the way over 12”. This makes it an inconsequential 22 1/2 - 67 1/2 - 90 degree right triangle, but what is important is understanding A still = 12” and now B = 24”. Square those both and add them together for 720 = C squared. The square root of 720 is 26.8328”. A 16th of an inch equals.0625 so we are just a hair over 26 13/16” total. With 11/16” fitting allowance for the 22 1/2 degree ell on both sides, I am thinking that piece of 2in PVC needs to be cut a hair over 25 5/8”. Anyway that’s my Euclidean Geometry offset math because remembering the Pythagorean Theorem is easier than memorizing trigonometry coefficients. Admittedly we weren’t allowed to use calculators on the exam so that means squaring the multiple choice answers and comparing them to the C squared calculation on scratch paper if you aren’t good at pulling square roots out of your hat. The 1/6 bends are even easier to figure because a 30-60-90 right triangle is also called a 3-4-5 right triangle and it makes figuring out lengths a matter of ratios and that can be done in your head without thinking about square roots. And for the bored silly folks I lost with that one, two words: exploding piñata
I'm with you, that's how I did it doing pipefitting with my grandfather. You can do it that way or figure out the hypotenuse by doing adjacent (12in) x 1/cos(45°) [where the 1.414 number comes from]. That should spit out 12 * ( 1 / ( sqrt(2) / 2 ) ) aka 12 x ( 2 / sqrt(2) ) which comes out to 24 / sqrt(2) or 16.971 Not sure if everyone has a calculator that can do sin, cos, tan, etc on the job site, though.. Hoping people know where the 1.414 number comes from now.
I used that same logic when figuring an offset with 22.5s. Though it seems logical, this isn’t the correct length of pipe you’d need. The constant for figuring a 22.5 offset is 2.613, which gives you 31.356, subtract 11/16 for fittings and you’re looking at roughly 30-5/8. After scratching my head on it a while, I realized even though you’re doubling the angle, it doesn’t double your rise.
@@jordanchaplin1334 Thanks for setting me straight if you’re right. I’ve been wrong before and I will be wrong again. It’s been four months so I don’t care enough to double check it. I was just being a know-it-all because the jerks at massage school put me in the remedial class and fed me test answers. It was an insult to my intelligence therefore the online persona overcompensated-which is better than mowing a bunch of people down.
Math based off center to center. 22° set x 2.6 = travel, 30° set x 2= travel, 60° set x 1.15 = travel. These numbers will get you closer than your eyeball. All your multipliers for every degree are on the trigonometry. Want to really have fun get into the minutes of the degree. Good video Rodger 👍
an oscillating tool works great for cutting 1-1/2" pipe in tight spaces, I use mine all the time! if they made longer blades it would work on Bigger sizes of PVC pipe!
Solid video, reminds me of the journeyman i was taught under, plumbing since he was 13 as his uncles were both plumbers, guy use to be spot on with eyeballing measurements made it look easy lol
Roger just wanted to say thanks. Also 5 year commercial plumber. I started out with a guy that did no math but I can tell you that 9/10 times he got his cut without math. And he would always get compliments from everyone because he’s been doing it for long he could eye ball
Coming from a combined local of plumbers and pipe fitters a lot of times the pipes that we were dealing with were much much bigger and also many feet in the air and welded pipe so of course in that situation you have to do the layout with plum bobs on the floor figure out the piece needed and then take it up and weld it in place the tolerance is critical and there's no room for mistakes on a welded six or eight inch chilled water pipe or a ten inch cast iron roof leader perhaps this is a easy way to teach the guys how to do it but the real reason to learn is that
The chicago license exam we had to do a rolling offset using math only,, a regular 45 set that isn't to log you can use a square edge say 12" mark 12 one way And 12" the other wayand measure 2 end points minus your 2 take offs for 1/8 bends
Been using this trick now since this video came out. I do central vacs, not plumbing, but this situation definitely applies. Even down to the dimensions of the tubing fittings. It definitely goes quite fast when you’re just doing it and not explaining.
I had done a small offset about a year ago in my laundry room to modernize the plumbing to in-wall laundry box faucets and drain. I had used Roger's method to do the offset correctly- most difficult part was finding the offsets at the HD.
This was a great video for basic Plumbing. I think you should also put one out there of how to properly use the transmission and motor switch on a sewer machine to send and retract the line properly. Many people buying the snake inside the drum just an idea.
do American plumbers not have fitting handbooks ? Up here in Canada we get given a book in our first year of plumbing that outlines the throw, pressure ratings ID.OD and engagement of any plastic, black iron, welded , copper, plastic pipe ect I know this as i just today finished my first bout of plumbing school.
I use this to find where to start a wye so its diagonal lands perfectly at a fixture or stack that's at the end of that section. If you're really good at this, it makes a big underground so fun. Other guys are using more fittings... guessing at perfection... never quite hitting it. While I'm smoking them by slamming waste and vent groups fast and clean and tight as a gnats ass... ah, good times 😊
I also use this to turn a horizontal 45° ell right before a closet bend... if I know the offset distance I can Calc backwards and add the fitting take off to land the 45 Tits on a Ritz
I know many of them don't have enough fingerings toes to count them. Just like home owners that can do the job,they just don't have the time to do the own diy's
I learned i am oldschool from this video lol. Spent 10 years plumbing in the oilfield if eyeballing ia good for 10kLbs of pressure. Its gooding enough for drain line. If things pool or siphone throw a brick on it or under it lol.
I would call it geometry and the simplified version pythagorus theorem when an and b are equal. So basically take the length and multiply by sqrt of 2 which is 1.4. The length is 10? The length you cut is 10 * 1.4 = 14.14 or about 14 1/8.
Definitely a good way to figure out the length for that offset but realistically you'd only do this if you were an hourly worker. Like Roger showed, the first way is way faster and usually just fine😄
I'm not a plummer, but I've known a lot of very good turd wranglers in my life. Without watching the video I wrote down 13 3/4". My thinking was 12 squared plus 12 squared equals 288. And 17 is the squareroot of 269, Acouple of things I've know for nearly 50 years. Then my guess was the fittings would take up about 3" subtract that from the 17" minus a little more and you will be close. "CLOSE ENOUGH CONSTRUCTION" As far as the 22.5 degrees I'd need my framing square and figure it like a rafter. BTW I a vintage carpenter and will check more of your videos.
The length of the pipe is the offset of the vertical pipe (in this case 12 in.) divided by the sin 22.5 (which is .38) which equals 31.36 inches. Or of you want a multiplier then take the inverse of .38 which is 1/.38= 2.61 and then multiply by 12 and get 31.36 inches. Most smart phones have a calculator with the sine function.
It’s time companies make rotary lasers, with an 45 angle option. We do a lot of concentric piping for gas boilers. Those pipes have different beginning and ends. We made a bracket/adapter to fit on the gas boiler pipe-end, so the laser is centred. So we can measure mid-air to our exit point. We made a table/formula to calculate how much pipe we need to ‘add’ for a specific rice of height. The laser produces 2 centre lines, perpendicular to each other. It works fast and precise.
Pro tip: take your set measurement in this case the side to side measurement, ADD the take off then cut the vertical distance that number. Then when you put your 45’s on the take off will bring it back the correct distance that matches the side to side measurement
Its not cheap, but I have used it every day on every cut of PVC for the past 6 months . Then I hit the inside with a pencil deburrer, and everything glues up way nicer.@@23tracy91
The answer to your question regarding the 22.5 degree angle is 1.08 x the horizontal distance, assuming like the physicist says that it is really a 90 + 45, or 90 + 22.5 angle in this case. The angle that we are computing from is the horizontal, and thus we can subtract 90 and work with either 45, or 22.5..The right triangle trigonometry approach from my high school days is: We know the horizontal distance, which is 12, and we know the angle down from the horizontal, 22.5. We want to know the length of the hypotenuse. The cos 22.5 = the adjacent over the hypotenuse. Solve for the hypotenuse. Multiply both sides by the hypotenuse, and divide by the cos 22.5. This will yield 1.08 times the adjacent. The vertical drop from the horizontal will be computed from the Tan 22.5 = opposite(vertical side) divided by the horizontal. Multiply both sides by the horizontal, and the vertical = horizontal times tan 22.5, or .4142 times the horizontal.
The math might seem onerous for a 2” chunk of PVC, but it it’s an 8” cast iron rain drain and it’s 20 feet in the air, doing the math makes a lot more sense.
I would use the 1.41 equation when running an offset in larger size pipe or if I was working with cast iron, its much easier that way. But I never bother with 1/16” increments
An old school plumber would already have that cut and glued before you did any of those calculations. And it would have looked good too! If you do a lot of rough ins and top out its quicker to "eye ball" it. I have seen this method a long time ago, but I just didn't use it.
Find C2C x 1.414 whatever number that is subtract your fittings thats your cut length, thats basic pipe fitting, constant moving rate of 45 degrees is 1.414
for the record, I googled hypotenuse ratio on a 22.5, 90 triangle I knew it was a ratio of angles, which could also be applied with sin but I did it the lazy way 1/sin22.5 degrees
Your answer is correct, if you are multiplying by the vertical distance shown in the video, and then the multiplier is 2.613, however we don't know the vertical distance. I believe the the question was based on the horizontal distance between the two pipes, then the answer is 1.08, or (1 divided by the cos 22.5) times the horizontal distance between the pipes.
For those saying eye ball works everytime. That may be almost true over a foot, but if you have to do this an arms length or more away youre just throwing darts at a dart board. If you can eyeball two 45s 5 feet away from each other and get both ends of the pipe ALL the way inside both hubs, kudos youre considerably more psycic than me.
O tambien puedes hacer A al cuadrado + B al cuadrado y sacas la raiz cuadrada. (12 x 12 )+ (12 x 12)= (144)+(144)=288 y sacas la raiz cuadrada =16.97" menos 3" =13 31/32
If pvc pipe cost the same as solid gold pipe, this would make sense, but it’s just pvc if it’s a little long trim it, if it’s short cut another, use the piece somewhere else. Also use a chop saw, smooth clean cuts every time.
Rolling offset 45 x1.414 22-1/2" x 2.613. Honestly this is more for pipefitters. Its good information to know but In the time it takes to make the calculation and execute, I could have completed job.
It's not a rolling offset bud. It's a 45° offset. You need a whole other mathematical equation to figure a rolling offset. A offset just changes width along the same plane. A rolling offset changes in width and elevation. Nice attempt at trying to flex though.
As a physicist that dwells in mathematics from time to time, LOL, I have to say that that's 135 degrees, not 45. Now another thing that I know from mathematics is that when you measure a center point on a round shape like a pipe, it can be pretty hard to find the actual center. It's much easier to measure from corner to corner if you have something up against it. That will actually give you the same measurement. Inner corner to inner corner or outer corner to outer corner.
It’s an offset angle, it’s measured from the position the pipe would be in if it continued on a straight alignment. On measuring centre to centre, if you find the point your straight edge contacts the object you are measuring you have found the point perpendicular to the centre of the object in the orientation of the direction between the two objects. If you want to get fancy, and go three dimensional, use a jigger, measure three or more points on the circumference of the pipe, use software to create a circle of best fit and extract the centre coordinates.
@@samwilliams1517 Yes, I do know that it's based on cutting the circle in half to 180 degrees and then measuring from the offset of the resulting line. That works fine in plumbing but I was just giving a bit of trivia as in math we measure from two divisible lines and the angle between them. Here you are suggesting that we measure from a non-existent line to a splice which is not how mathematics are done. You measure between the lines you can determine. So in this case it would be 90 degrees plus 45 which is 135. And then the offset angle that is missing to get to 180 is 45 but the angle is technically 135 and 225 respectively. Thank you.
Ok, let’s go with your assertion that we cannot measure to a line that we would have if we extended the pipe. What you are missing is that pipes have a flow direction, hence you are not measuring the angles between two ‘lines’, but instead two ‘vectors’ they have a direction, if by your assertion the water is to flow back on itself to conform to your view that we cannot assume the pipe continues, then the flow vectors are reversed, meaning we measure a 180degree angle between them, hence we must remove 135degrees and end up at a 45 degree angle between the flow vectors . Hopefully this makes more sense from a mathematical viewpoint.
@@samwilliams1517 I understood it without you having to explain it. I know where the 45 is coming from I'm just saying that that technically is no 45 degree angle
I just take my two 45s line em up with my eagle vision havent been wrong since. Could be off like 1/32” maybe, but hey whats that. I was blessed with eagle eyes.
Pythagorean theorem kids. Your high school teacher couldn’t give you any practical application for trigonometry because that high school teacher had no life experience to relate a curriculum lesson to real life. A2+b2=c2. It’s that simple to get that hypotenuse.
Yep, but unless you have adjustable angle connectors like HVAC, it’s only going to be 30s, 60s, or 45s. So most people only need to memorize the ratio 1 :sqrt(3):2 or 1:sqrt(2).
Easy way to do this glue your 45 on and a long enough piece running to the other pipe. Once you get that done cut the other pipe to fit into hub and your done
Great idea for an educational video brother. I hear this question all the time. But I'm old school. You lost me when you pulled out the tape measure and started talking math. 😂 just kidding 😂
Yeah it's really quite easy and if you did not fall asleep in math class in like the 6th grade you should know how to do it because if you don't know how to find the area of a square and you don't know how to divide that by two then you need to go back to school.
I think this method what's more useful important when working with copper galvanized or cast iron piping. Pvc has made it a cakewalk.. Hell I cut it three times and it's still too short😂😂
Would have been fired thirty seconds not having that done in residential here in alberta. Important to know if you ever fit for welders or use expensive materials
Love this man. It’s nice to see older guys try to get young guys involved in plumbing. It’s a great trade if you really take pride in your work because it really feels like art a lot of the time.
(𝖦𝗈𝗈𝖽 𝗆𝗈𝗇𝖾𝗒 𝗍𝗈𝗈)😂
Thank you so much. I have always loved this trade. All the trades really. But I think plumbing is the most amazing profession…
Im 24 and i always feel accomplished after work
For all that's curious. He used 1.41 because that's the secant of theta 45 degrees..... If you have a different angle that needs to be made, use your calculator and type in that degree of angle you want then the (sec) button. The number you see you then multiply by your, "center to center" measurement.
If you don’t have the sec button, like on calculator in iPhones, then just input the angle and press cos. Then press m+ (make sure your memory is cleared by hitting mc). Then press 1, then press divide, then press mr which will recall the cosine of the angle you just input.
You could also do 1/sin(angle)
45 are the 2nd most common in any construction piping trade
I did that on my phone using a 22.5° angle
I put "1÷sin(22.5)= 2.61
What does that 2.61 mean or for?@@deserthandz7145
I needed this info! Thank you!
GREAT JOB!! As a union journeymen plumber in chicago who didnt take the whole 5 yrs to get state license i was taught the first 6 months of apprenticeship the formulas for all offsets. My instructor use to call ppl that eyeballed measurements clowns and would roast them. For the ppl that say you'd be fired for doing math obviously dont know how to do math because while your eyeballing fitting to fitting ive figured out every cut piece just by pulling measurements. But each their own i understand some may not be mathematically inclined but keep up the great videos mr. Wakefield im sure your helping alot of ppl
Was that instructor frank from the 130 school?
@@jakekennedy9161yep uncle frank probably one of the smartest ppl I've ever meet
@courtneyelkins2366 are you still in Chicago... im always looking for a good plumber.
You could eyeball it, screw up, do it again to do it twice to fix it and still be done faster than this guy! A chain vise for PVC, give me a break!
@beingmoody7577 yes I'm still In Chicago
For an experienced plumbing contractor like myself, all you need is a tape measure and a good eye, no math required! Done it enough times over the last 35 years 👍
It's never too late to learn to do it the easy way. math is a tool don't be scared of it
I'm a plumber in NC and I have never seen this method i will try it it next time i come across a 45° vent situation. I love your videos Mr.Wakefield.
Once you learn and practice plumbing with math, it really speeds the job up. You can use it a lot of different ways, with a lot of different fittings.
as a Plumbing contractor of 23 years, I just use the old school method, "eyeball it" I'm good enough at my profession to do that! have never used the formula since I took the plumbing test! great video non the less! All apprentices need to know how to do the math too! 😁👍
Right on, where you ever taught how to use the formulas? While eyeballing does work for most people...I think it's a good foundation that everyone at least knows the formulas
@@RogerWakefield I have always (or almost always ha) use the formula. I was taught to memorize what 1.4 times 2 through 9 is. 1.4 is close enough unless you are welding. That way, you can do the math in your head. If eyeballing it works for ya, more power to ya. Just know that the numbers don't lie.
Here we go again having yet another plumber with zero confidence blowing his own horn to let the world know that "YOUR THE MAN".
@@RogerWakefieldyou have to tilt your head a little bit for the eyeball method lol.
I love the “it’s ok it’s in the wall.”😂
I hope they don't pay u in hours
More practical videos like this please.
I'm an electrician and got more out of this compared to other vids for emt 😂 Got what I wanted here, thanks! You're a great teacher.
Glad I could help!
Never got taught this, loved it! Stovepiping with the "magic eye" gives instantaneous measurements though, the foreman I trained under was like this. Crazy fast with dwv, his eye was so well trained he'd set up pipes or fittings without a torpedo and ask us to check it later. Always level or on mark. Would only see him pull a 2' foot level to set grade in ground. I'm not as good so thanks alot for showing us this video. Really appreciate the knowledge and insight, still hooked on stove piping but will start memorizing the percentage of 1/16ths and see if the noggin can keep pace.
Great vid, teaches how it works AND why it works, a MUST for a tradesman even though it may be eyeballed most of the time.
Awesome, plumber here and I forgot how to do a 45 offset using 1.41. I’ll probably end up using it now to make those 45s crisp and less room for error. I’m used to eyeballing now but always trying to improve
I am old school and was taught math early on as well as marking locations and dropping a plumb line and snapping chalk lines. Then adding fittings and drilling hangers. To be a good plumber you need to spend about 4 years in all types of plumbing and then pick which one to stick with or do like we did and just do all of it
Okay, I can certainly apply the Pythagorean Theorem to calculate the length of the center to center offset for both. Let’s back up and refigure the two 45 degree ells first. We have to visualize a right triangle in the stud bay to visualize it. Go to 8:30 in the video and then superimpose the horizontal tape measure visually and you will see a triangle. That is a 45-45-90 right triangle and can even be drawn in the stud bay with pencil to make it easier to explain.
We know the length of the tape measure side is 12”. We will call that side A and by definition the other leg of the triangle (which is mostly covered by 2” vertical PVC on the right that is about to be cut off) must also be 12”. There’s our A and B sides and the center to center length of the diagonal pipe (plus a bit of fitting on either end) is C, our hypotenuse.
Apply the Theorem. A squared plus B squared equals C squared. 144” + 144” = 288”. C squared equals 288, so find the square root of 288 for the length of the diagonal, which is 16.97”. That is closer to 17 by a hair, but we could call it 16 31/32” to split the difference and be very close. Subtract off the 1 1/2” from both sides for the fitting and that pipe is cut a smidge shorter than 14”. Same result different paths.
Go back to that same imaginary triangle to get our difference in height. That leg of the triangle is 12”. Add 1 1/2” fitting allowance on both sides to get an extra 3” and there is your 15” vertical difference. Figuring that part is tremendously easy now.
To solve the problem of a two 22 1/2 degree fittings making the offset go back to 8:30 on the video. That 45 degree angle between the two pipes that form the bottom of the triangle is now bisected. What that does is the pipe travels half as far to the left in that 12” vertical, so the vertical leg must be doubled to bring the diagonal all the way over 12”. This makes it an inconsequential 22 1/2 - 67 1/2 - 90 degree right triangle, but what is important is understanding A still = 12” and now B = 24”. Square those both and add them together for 720 = C squared. The square root of 720 is 26.8328”. A 16th of an inch equals.0625 so we are just a hair over 26 13/16” total. With 11/16” fitting allowance for the 22 1/2 degree ell on both sides, I am thinking that piece of 2in PVC needs to be cut a hair over 25 5/8”.
Anyway that’s my Euclidean Geometry offset math because remembering the Pythagorean Theorem is easier than memorizing trigonometry coefficients. Admittedly we weren’t allowed to use calculators on the exam so that means squaring the multiple choice answers and comparing them to the C squared calculation on scratch paper if you aren’t good at pulling square roots out of your hat.
The 1/6 bends are even easier to figure because a 30-60-90 right triangle is also called a 3-4-5 right triangle and it makes figuring out lengths a matter of ratios and that can be done in your head without thinking about square roots.
And for the bored silly folks I lost with that one, two words: exploding piñata
I'm with you, that's how I did it doing pipefitting with my grandfather. You can do it that way or figure out the hypotenuse by doing adjacent (12in) x 1/cos(45°) [where the 1.414 number comes from]. That should spit out 12 * ( 1 / ( sqrt(2) / 2 ) ) aka 12 x ( 2 / sqrt(2) ) which comes out to 24 / sqrt(2) or 16.971
Not sure if everyone has a calculator that can do sin, cos, tan, etc on the job site, though..
Hoping people know where the 1.414 number comes from now.
I used that same logic when figuring an offset with 22.5s. Though it seems logical, this isn’t the correct length of pipe you’d need. The constant for figuring a 22.5 offset is 2.613, which gives you 31.356, subtract 11/16 for fittings and you’re looking at roughly 30-5/8.
After scratching my head on it a while, I realized even though you’re doubling the angle, it doesn’t double your rise.
@@jordanchaplin1334 Thanks for setting me straight if you’re right. I’ve been wrong before and I will be wrong again. It’s been four months so I don’t care enough to double check it. I was just being a know-it-all because the jerks at massage school put me in the remedial class and fed me test answers. It was an insult to my intelligence therefore the online persona overcompensated-which is better than mowing a bunch of people down.
@@Zildjian0321 thanks for explain this!
Math based off center to center. 22° set x 2.6 = travel, 30° set x 2= travel, 60° set x 1.15 = travel. These numbers will get you closer than your eyeball. All your multipliers for every degree are on the trigonometry. Want to really have fun get into the minutes of the degree. Good video Rodger 👍
2.6 multiplier. Great video!
an oscillating tool works great for cutting 1-1/2" pipe in tight spaces, I use mine all the time! if they made longer blades it would work on Bigger sizes of PVC pipe!
Solid video, reminds me of the journeyman i was taught under, plumbing since he was 13 as his uncles were both plumbers, guy use to be spot on with eyeballing measurements made it look easy lol
Roger just wanted to say thanks. Also 5 year commercial plumber. I started out with a guy that did no math but I can tell you that 9/10 times he got his cut without math. And he would always get compliments from everyone because he’s been doing it for long he could eye ball
Coming from a combined local of plumbers and pipe fitters a lot of times the pipes that we were dealing with were much much bigger and also many feet in the air and welded pipe so of course in that situation you have to do the layout with plum bobs on the floor figure out the piece needed and then take it up and weld it in place the tolerance is critical and there's no room for mistakes on a welded six or eight inch chilled water pipe or a ten inch cast iron roof leader perhaps this is a easy way to teach the guys how to do it but the real reason to learn is that
. When we ran cast iron, b&s, we always had to lay it out with 1.414 for a 45 . Thanks for sharing this
The chicago license exam we had to do a rolling offset using math only,, a regular 45 set that isn't to log you can use a square edge say 12" mark 12 one way And 12" the other wayand measure 2 end points minus your 2 take offs for 1/8 bends
Been using this trick now since this video came out. I do central vacs, not plumbing, but this situation definitely applies. Even down to the dimensions of the tubing fittings. It definitely goes quite fast when you’re just doing it and not explaining.
You should also show how to calculate for rolling offsets and equal spread offsets.
Lastly, we use a sawsall, but I prefer using a miter saw to cut.
I had done a small offset about a year ago in my laundry room to modernize the plumbing to in-wall laundry box faucets and drain. I had used Roger's method to do the offset correctly- most difficult part was finding the offsets at the HD.
This was a great video for basic Plumbing. I think you should also put one out there of how to properly use the transmission and motor switch on a sewer machine to send and retract the line properly. Many people buying the snake inside the drum just an idea.
do American plumbers not have fitting handbooks ? Up here in Canada we get given a book in our first year of plumbing that outlines the throw, pressure ratings ID.OD and engagement of any plastic, black iron, welded , copper, plastic pipe ect I know this as i just today finished my first bout of plumbing school.
I use a stick rule. It gives you the hypotenuse. Then you just gotta do the fitting take off. Stick rule is the best.
I use this to find where to start a wye so its diagonal lands perfectly at a fixture or stack that's at the end of that section. If you're really good at this, it makes a big underground so fun. Other guys are using more fittings... guessing at perfection... never quite hitting it. While I'm smoking them by slamming waste and vent groups fast and clean and tight as a gnats ass... ah, good times 😊
I also use this to turn a horizontal 45° ell right before a closet bend... if I know the offset distance I can Calc backwards and add the fitting take off to land the 45
Tits on a Ritz
If you do this on a construction site ,it will be your last day. Boss" wheres johnny?" Foreman" he spent 2.5 hours to run a 2" vent x 3' long
😂😂
I call it bs. Because these"smartguys" measure once cut 8 times and still short
I know many of them don't have enough fingerings toes to count them. Just like home owners that can do the job,they just don't have the time to do the own diy's
I really appreciate the time you take out of your day to gives us a little brain food
Facts this is for the test they make it more difficult than it is time is money on the field.
I learned i am oldschool from this video lol. Spent 10 years plumbing in the oilfield if eyeballing ia good for 10kLbs of pressure. Its gooding enough for drain line. If things pool or siphone throw a brick on it or under it lol.
I would call it geometry and the simplified version pythagorus theorem when an and b are equal. So basically take the length and multiply by sqrt of 2 which is 1.4.
The length is 10? The length you cut is 10 * 1.4 = 14.14 or about 14 1/8.
Definitely a good way to figure out the length for that offset but realistically you'd only do this if you were an hourly worker. Like Roger showed, the first way is way faster and usually just fine😄
I'm not a plummer, but I've known a lot of very good turd wranglers in my life. Without watching the video I wrote down 13 3/4". My thinking was 12 squared plus 12 squared equals 288. And 17 is the squareroot of 269, Acouple of things I've know for nearly 50 years. Then my guess was the fittings would take up about 3" subtract that from the 17" minus a little more and you will be close. "CLOSE ENOUGH CONSTRUCTION" As far as the 22.5 degrees I'd need my framing square and figure it like a rafter. BTW I a vintage carpenter and will check more of your videos.
That's funny
Much appreciated. Thank you for sharing.
My pleasure! Is this how you measure an offset?
@RogerWakefield I'm new school, but apparently, I've been doing it old school the entire time. 😅
That formula also works on sheet metal 45 * elbow , been using this formula for years on duct ells !!
2.613 been a plumber for 5 yrs
“Make up” is where the pipe stops in the fitting.
“Take off or Take out” is the distance from center of the fitting to the end of the pipe.
The length of the pipe is the offset of the vertical pipe (in this case 12 in.) divided by the sin 22.5 (which is .38) which equals 31.36 inches. Or of you want a multiplier then take the inverse of .38 which is 1/.38= 2.61 and then multiply by 12 and get 31.36 inches. Most smart phones have a calculator with the sine function.
It’s time companies make rotary lasers, with an 45 angle option. We do a lot of concentric piping for gas boilers. Those pipes have different beginning and ends. We made a bracket/adapter to fit on the gas boiler pipe-end, so the laser is centred. So we can measure mid-air to our exit point. We made a table/formula to calculate how much pipe we need to ‘add’ for a specific rice of height. The laser produces 2 centre lines, perpendicular to each other. It works fast and precise.
Pro tip: take your set measurement in this case the side to side measurement, ADD the take off then cut the vertical distance that number. Then when you put your 45’s on the take off will bring it back the correct distance that matches the side to side measurement
@5:23 Roger, I'm runnin' circles around ya with the Reed DEB4! I quit packing files in my tool caddy after getting one.
Thank you so much for this comment. I've been looking for a tool like that for so long.
Its not cheap, but I have used it every day on every cut of PVC for the past 6 months . Then I hit the inside with a pencil deburrer, and everything glues up way nicer.@@23tracy91
The answer to your question regarding the 22.5 degree angle is 1.08 x the horizontal distance, assuming like the physicist says that it is really a 90 + 45, or 90 + 22.5 angle in this case. The angle that we are computing from is the horizontal, and thus we can subtract 90 and work with either 45, or 22.5..The right triangle trigonometry approach from my high school days is: We know the horizontal distance, which is 12, and we know the angle down from the horizontal, 22.5. We want to know the length of the hypotenuse. The cos 22.5 = the adjacent over the hypotenuse. Solve for the hypotenuse. Multiply both sides by the hypotenuse, and divide by the cos 22.5. This will yield 1.08 times the adjacent. The vertical drop from the horizontal will be computed from the Tan 22.5 = opposite(vertical side) divided by the horizontal. Multiply both sides by the horizontal, and the vertical = horizontal times tan 22.5, or .4142 times the horizontal.
Bad ass 💯. Only thing I'd add would be one of them fancy cone shaped ream / chamfer cutters. 😉
Nice tip!
Eyeball and dry fit. Then grasshopper measure center to center and subtract takeoff/makeup.
Are u gonna have to cut travel piece and and glue this for journey man test or just find the offset with the 1.41 equation
Good video sir,you could use a metal cutting blade instead of that wood blade, will cut a lot smoother.
sin(22.5) = (horizontal run)/hypotenuse.
Hypotenuse = horizontal/sin(22.5) = 2.613 x horizontal.
The math might seem onerous for a 2” chunk of PVC, but it it’s an 8” cast iron rain drain and it’s 20 feet in the air, doing the math makes a lot more sense.
Guessing it works the same when going from a horizontal to vertical piping?
Cool video
I would use the 1.41 equation when running an offset in larger size pipe or if I was working with cast iron, its much easier that way. But I never bother with 1/16” increments
Good info thank you for the video.
It is always the rise or the run which should be equal times the square root of 2. Special right triangle.
An old school plumber would already have that cut and glued before you did any of those calculations. And it would have looked good too! If you do a lot of rough ins and top out its quicker to "eye ball" it. I have seen this method a long time ago, but I just didn't use it.
Find C2C x 1.414 whatever number that is subtract your fittings thats your cut length, thats basic pipe fitting, constant moving rate of 45 degrees is 1.414
3 weeks to rough in a 2 bathroom house with this pace lol
That's how hourly guys get their money
lol that is one way of looking at it. thank you for your videos roger! i have learned alot, and applied the knowledge to my business.@@RogerWakefield
We call the measurement technique 'Leading edge to leading edge' in the electric business.
Eyeballing gets it for me every time 😂 25 years strong
How do you set up your sale items?
Good info.
Thanks! Are you an eyeballer or a math genius?
for the record, I googled hypotenuse ratio on a 22.5, 90 triangle
I knew it was a ratio of angles, which could also be applied with sin but I did it the lazy way
1/sin22.5 degrees
Your answer is correct, if you are multiplying by the vertical distance shown in the video, and then the multiplier is 2.613, however we don't know the vertical distance. I believe the the question was based on the horizontal distance between the two pipes, then the answer is 1.08, or (1 divided by the cos 22.5) times the horizontal distance between the pipes.
I thought I was gonna learn something. I’ve used the eyeball it method since I started plumbing and will be sticking to it.
It's not for everyone. If you struggled with math in fifth grade you should stick to eyeballing it.
I got lost when you measured the hubs. So horizontal offset is 12", and vertical is 16"? What was the 2 1/2" and 1" make up hubs?
For those saying eye ball works everytime. That may be almost true over a foot, but if you have to do this an arms length or more away youre just throwing darts at a dart board.
If you can eyeball two 45s 5 feet away from each other and get both ends of the pipe ALL the way inside both hubs, kudos youre considerably more psycic than me.
Measure the horizontal run. Take that number + 1/2 that number & add it. The nearest whole # go back that many 16ths.
Man I just close my lazy eye and make the cut like I’m pulling the trigger
How often does that work for ya? 😅
😂😂😂
O tambien puedes hacer A al cuadrado + B al cuadrado y sacas la raiz cuadrada. (12 x 12 )+ (12 x 12)= (144)+(144)=288 y sacas la raiz cuadrada =16.97" menos 3" =13 31/32
I’ll just stay eyeballing it thanks
Is there a purpose to the offset?
the most impressive part of this vid was that straight sawzall cut... rogers a freaking laser
Teach about rolling offset
Done it
If pvc pipe cost the same as solid gold pipe, this would make sense, but it’s just pvc if it’s a little long trim it, if it’s short cut another, use the piece somewhere else. Also use a chop saw, smooth clean cuts every time.
I believe it’s 2.613 for 22 offsets
I wish I knew this the first time I did a water main offset. Eye balling 12" water main 10' down in the ground doesn't work the best.
I’m sure you know that the offsets and cut sheets are in the code books
Can you use a laser of some sort?
Great way to doit right, What's the app name?
If the multiplier for 45 degrees is 1.41 then the multiplier for 22.5 degree should be .705, no?
Rolling offset 45 x1.414
22-1/2" x 2.613. Honestly this is more for pipefitters. Its good information to know but In the time it takes to make the calculation and execute, I could have completed job.
There is a reason why you need these calculations. You need the proper amount of air per cubic foot to vent a drain RIGHT
It's not a rolling offset bud. It's a 45° offset. You need a whole other mathematical equation to figure a rolling offset. A offset just changes width along the same plane. A rolling offset changes in width and elevation. Nice attempt at trying to flex though.
As a physicist that dwells in mathematics from time to time, LOL, I have to say that that's 135 degrees, not 45. Now another thing that I know from mathematics is that when you measure a center point on a round shape like a pipe, it can be pretty hard to find the actual center. It's much easier to measure from corner to corner if you have something up against it. That will actually give you the same measurement. Inner corner to inner corner or outer corner to outer corner.
It’s an offset angle, it’s measured from the position the pipe would be in if it continued on a straight alignment.
On measuring centre to centre, if you find the point your straight edge contacts the object you are measuring you have found the point perpendicular to the centre of the object in the orientation of the direction between the two objects.
If you want to get fancy, and go three dimensional, use a jigger, measure three or more points on the circumference of the pipe, use software to create a circle of best fit and extract the centre coordinates.
@@samwilliams1517 Yes, I do know that it's based on cutting the circle in half to 180 degrees and then measuring from the offset of the resulting line. That works fine in plumbing but I was just giving a bit of trivia as in math we measure from two divisible lines and the angle between them. Here you are suggesting that we measure from a non-existent line to a splice which is not how mathematics are done. You measure between the lines you can determine. So in this case it would be 90 degrees plus 45 which is 135. And then the offset angle that is missing to get to 180 is 45 but the angle is technically 135 and 225 respectively. Thank you.
Ok, let’s go with your assertion that we cannot measure to a line that we would have if we extended the pipe.
What you are missing is that pipes have a flow direction, hence you are not measuring the angles between two ‘lines’, but instead two ‘vectors’ they have a direction, if by your assertion the water is to flow back on itself to conform to your view that we cannot assume the pipe continues, then the flow vectors are reversed, meaning we measure a 180degree angle between them, hence we must remove 135degrees and end up at a 45 degree angle between the flow vectors .
Hopefully this makes more sense from a mathematical viewpoint.
@@samwilliams1517 I understood it without you having to explain it. I know where the 45 is coming from I'm just saying that that technically is no 45 degree angle
Same mulitipliers we use for conduit offset.
I just take my two 45s line em up with my eagle vision havent been wrong since. Could be off like 1/32” maybe, but hey whats that. I was blessed with eagle eyes.
A gift very few have ever received
What app are you using sir? 4 year apprentice and taking my journeyman test at the end of this month
Its called tech tools on the app store...its a red and black circle
How did it go ? Did you pass ? I take mine next month
Pythagorean theorem kids. Your high school teacher couldn’t give you any practical application for trigonometry because that high school teacher had no life experience to relate a curriculum lesson to real life. A2+b2=c2. It’s that simple to get that hypotenuse.
Yep, but unless you have adjustable angle connectors like HVAC, it’s only going to be 30s, 60s, or 45s. So most people only need to memorize the ratio 1 :sqrt(3):2 or 1:sqrt(2).
Easy way to do this glue your 45 on and a long enough piece running to the other pipe. Once you get that done cut the other pipe to fit into hub and your done
Great idea for an educational video brother. I hear this question all the time.
But I'm old school. You lost me when you pulled out the tape measure and started talking math.
😂 just kidding 😂
Just dry fit and dont cut too short and that will make eyeballing easier
You need to do it this way, say you’re working in a sewer treatment plant and it’s 36 inch pipe, then you absolutely have to do it this way
Yeah it's really quite easy and if you did not fall asleep in math class in like the 6th grade you should know how to do it because if you don't know how to find the area of a square and you don't know how to divide that by two then you need to go back to school.
I had to guess the offset when I took my exam in Austin....everything else was ez
CM for 22.5° is 2.6
22.5 COSECANT is 2.6
I think this method what's more useful important when working with copper galvanized or cast iron piping. Pvc has made it a cakewalk..
Hell I cut it three times and it's still too short😂😂
Why you don't get a PVC cutter way easier @RogerWakefield
Lol 😂
Great video! 2.61
Would have been fired thirty seconds not having that done in residential here in alberta. Important to know if you ever fit for welders or use expensive materials
Ok, how do you do a 22.5?
This Electrical apprentice who loves bending emt pipes says the multiplier for 22.5 offsets is 2.6
You should do a plumbing school channel, I bet it would be hugely popular