How To Cut An Ellipse For A Round Pipe Through A Pitched Roof

[@vnrkain1169]

Thank you for this most helpful video. I am a retired guy living in a rural village in northern Việt Nam. Nobody, and I mean NOBODY, has or had any understanding of what I wanted to do so the chimney could go through my roof. " cut hole, push pipe through, drink tea". So now there is a nice elliptical hole around the chimney which means nothing to anyone except me. Sigh😊

[@colomacountry]

Beautiful, the only times I enjoy math is when I can apply them to real world tasks. If only school mathematics was this fun! Thanks! Every video out there, skips this step when installing the stove pipe.

[@geddins14]

Thank you sir for this video. Very informative.

[@roadking6414]

Awesome! I might have to get "The Steel Square". Appreciate the post.

[@aidanpowell175]

Everything you need and nothing you dont. Cheers for the quality content!

[@Robby4Jesus]

Awesome video, Thanks. I couldn't have asked for a better tutorial.

[@TaipanTex]

Excellent video. Very well done and exactly what I needed to know for an oval hole I needed to cut in my metal roof. Thanks.

[@carybrief5874]

Excellent explanation, no bs, just clear, excellent information, no doubt you have done this before

[@OlTrailDog]

I need to run a temporary flue through a window at a 45. This is what I was needing to layout my ellipse. Thanks.

[@allenro1]

I was a form carpenter for a short time and this "formula" was always interesting to me. I had forgotten how i was tought which led me to this video. Very informative. Thank you sir...🖒

[@DenBeans]

Thanks Mr. Herrick Kimball, I appreciate your time and effort.

[@Robby4Jesus]

Thanks for the book recommendation. I found it for under $20 at my favorite online used book vendor.

[@ramhornjoe]

Thanks a million, getting ready to install a 6inch chimney through a 3/12 pitched metal roof and needed this info very helpfull.

[@vincebrown8040]

Absolutely brilliant! Exactly what it was looking for. Thank you.

[@justamusta]

This is excellent. I'll be on my roof next weekend using this method.

[@TobiasMetalArt]

This videos saved me tons of time! Thanks!

[@EugeneHKrabs-by5vc]

Literally at work watching this lmao ur a life saver my guy 👍🏻

[@rudyrangel5910]

Thank you for this video. I have a job Monday on a exposed ceiling and this is going to make me look like the man! 💪🏽😂. God bless

[@johndrazic7665]

Brilliant! Thanks for sharing your knowledge!

[@chuggns]

I shine my laser tape from the 4 sides of the pipe and mark each point. Circle and cut from inside

[@jacksak]

This video is very interesting, useful and fun. Thanks.

[@anpier926]

Thank you, helpfull and simple!

[@TheEvilOnePlus1]

I used this method to put an 18" piece of spiral duct through a 45° wall. The fit is so snug it will barely need any caulking. Thanks for the instruction.

[@lukassteipe8679]

Thank you sir! Very helpful.

[@TrainerSteveRKC]

Awesome. Thank you🙏🏼

[@valeriemckay7064]

I have to put the hole in the roof for a chimney pipe this week. Odd shallower pitch though but this will be perfect. I love it when my kids old ma can baffle them, thanks. Ordered the book too, a little over 10 dollars, a steal.

[@Highintensityhealth]

Great video! Thanks so much

[@kennydieu2694]

Great video and thanks for sharing .

[@cyril111111]

This is most helpful. I’m still a bit unsure as how to determine my center in the roof. I saw a comment below about using a plum line, but I am not confident in how to use this method. I am going straight up with 6” duct from a range hood.

[@herrickkimball]

I hope it worked out for you. Lacking a plumb bob I would plumb up using a 4ft level. But the plumb bob is a great tool. You can achieve the plumbing effect by hanging any kind of weight on the end of a string. In other words, an actual plumb bob is not a necessity.

[@jimlthor]

I would put a laser level on the side of my pipe and pull a tape measure the radius of the pipe to mark center. Then do the same from the side 90° away. Don't forget to take off for the height of your laser on your level. The other way would to be hang a plumbbob and have someone measure where it lands in the pipe until you find the center, then mark it

[@nomadicoasis9260]

Thanks for that , rather genius.

[@jonathandowie3008]

Excellent video! Thank you so much! Liked and subscribed!

[@Matt-zz6ul]

Great video, does anybody know how I can use this method if I have the angle of the roof in degrees. Aussie here and we're all about metric system and degrees. Any help appreciated. So far I've just been converting angle into pitch

[@scottdieboldsr.3594]

What would the A and B be for 10.50 diameter chimney be without adding the 2 inches for space please?

[@bobbysilver272]

That's a great explanation. I was hoping there would be a quicker way, buy hey ho....At least this way, it will be 100% correct. Thank you.

[@jimlthor]

There is a quicker way.. but you'll still have to lay it out. Take the diameter of your pipe, divide it by the cosine of your angle. So it'll look like this w= d/cos(angle) A 6 inch pipe going thru a 45 degree surface would be W=6/cos(45) So the long point of your ellipse would be 8.48" and the narrow part would be 6"

[@rksg2003]

My second time watching this first off Thank You for making this video.. Second tell me how to align both those holes (ceiling & roof) when i do my install..

[@herrickkimball]

Use a plumb bob. Or a string with a small weight on the end. 👍

[@rksg2003]

@@herrickkimball thank you. I’m ordering that book

[@kyleroberts6451]

the part in the box is the cofusing part, can you explain

[@tregrad]

I noticed that with your 1/4 elipse template you flipped it over after you drew the first 1/4. you used one side of the template on opposing 1/4ers and the other side for the other opposing corners, is this necessary?

[@Lex-pq9bl]

Thanks for most interesting lesson. Question for you. The 12 inch X axis and 6 inch Y axis are stimulating the roof pitch yes? Hence you say it's always 12 on the X axis correct?

[@herrickkimball]

Yes, and yes to both questions. 👍

[@philgraves7814]

Thanks bro

[@mikemike7397]

Can you please make a video showing the next process?

[@kyleroberts6451]

does anyone have th etable from the book. I have a 8" pipe and need that data

[@frankwoodman7901]

Will this method work on a 2/12 pitch

[@herrickkimball]

Yes. But your ellipse will be nearly round with a pitch that low.

[@frankwoodman7901]

@@herrickkimball thank you sir for your response and and information

[@schwinnbiking]

what if its 6" rise and run, 45 degrees.. so both holes at 6" and you get a circle, that wont work

[@SillySatire]

Nifty. 👍

[@rodneyhall1435]

Great video but I was hoping you would explain how to determine the pitch of the roof.

[@dwills135]

How did you mark the hole centerline on the underside of the roof? plum line?

[@herrickkimball]

Yes. I started at the stove on the first floor and used a plumb bob to locate the location of the ceiling bracket. Then, after that was in, I used the plumb bob to find the location if the ceiling cutout on the 2nd. floor. Then I again used the plumb bob to determine the center on the underside of the roof sheathing. "Plumb bobs don't lie." :-)

[@dwills135]

Herrick Kimball Great! Thanks for the reply!

[@banburys]

Really helpful video but I am sorry but I am being a bit thick in not quite understanding how do you calculate from pitch to the measurement. I have a 30 degree pitch so how do I get the one measurement??

[@herrickkimball]

Your 30-degree angled roof has a 7/12 pitch. As shown on this web page: www.pole-barn.info/roof-pitch.html

[@tas_wild]

I wish I could make sense of this in millimetres. 🤦🏼‍♀️

[@tedperzanowski113]

Thanks I wish you would of showed the difference between a 12 inch template and the elliptical.

[@scottdavidson6371]

One question. When you make the hole in the trammel for the pencil you say it doesn't matter where it goes. Just at the end somewhere. Wouldn't this matter as if the pencil hole is in a different spot the radius would change?

[@scottdavidson6371]

Wouldn't the pencil have to go in a notch at the end of the trammel so the correct radius is maintained?

[@herrickkimball]

Hi Scott, If your A and B measurements are made from the pencil hole correctly, it makes no difference where the pencil hole is in relation to the end of the trammel stick.

[@scottdavidson6371]

Thanks mate. That makes sense now. I thought you were measuring from the end of stick. Thanks for the advice. Just doing this work now in Australia in lockdown to keep busy.

[@colomacountry]

Either I'm using the wrong terminology or it's just not online, but how the heck do you cut a square/rectangle hole in an angled ceiling for a support box?

[@herrickkimball]

If your square support box is installed level and you need to make a square hole to match in an angled roof above it, I would just drop a plumb bob down from inside the roof to the four corners of your level box. That will give you your outside dimensions. That is, if I understand your question correctly. Best wishes. 👍

[@DavetheVillaFan]

I have to do same job but my roof angle is 57* - I’m not sure what a 6-12 pitch is in terms of angle - can you help please?

[@herrickkimball]

Hi Dave, That's a really steep pitch. I wonder if your angle is actually 33°, which is an an 8-12 pitch. (I came up with 33 by subtracting 57 from 90). This link may help you: www.blocklayer.com/riseruneng.aspx By the way, a 6-12 roof is really easy to walk. 8-12 is too steep to comfortably walk. Best wishes.

[@DavetheVillaFan]

Herrick Kimball thanks for swift response. It’s definitely 57* - measured with a digital level but I guess 60would be near enough to make it easier.

[@jdizzle312]

I wish I had the confidence to do this. I need to install a vent. 😳

[@TheLalooo666]

I ended up with a hole that was 2 inches wider than I wanted. Didn’t kill the project but I don’t know what I did wrong.

[@herrickkimball]

🤔. Hmmm. Sorry to hear that. Somehow you added an inch to your measurement, which would translate to 2" wider than needed. Back to the drawing board.... I hope you figured it out . 👍

[@lukeshenefield9470]

@@herrickkimball Well I did cut the paper and then went ahead and cut the hole in the roof without remeasuring the paper... that would have been good. Flashing covered the hole fine, and the chimney's in! Thank you.

[@shanejake]

From the hole in your roof. Just get a pencil on a string with a nail and go around with the string and make the dimension.

[@brownboy6844]

I apologize for my ignorance but what if the hole you needed to make was 26 inches and the radius was 13 inches how would you draw that up if the horizontal line of the roof pitch is always 12?

[@allenro1]

Good question....im guessing you double the 12 inches but obviously keep the pitch the same...i hope he responds to this. 🤔

[@themjohnsons]

Great video-thank you