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how do you figure shingles for roof ?

stitan06

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so just bought our house last july and it needs a new roof im doing myself i have done roofs before but my boss figs how much we need i know it l X w to find square footage but my question is i have a porch roof that butts into my house roof how do i fig for the valley and that part of the roof :confused:
 
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NUTTSGT

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Find the square footage of the roof. Length x width = sq ft. 100 square feet equal 1 square.

3 bundles (normally unless you buy some dimensional shingles) = 1 square

I'd add 10% for scrap and that should get you close for the waste on the valleys. The porch roof will be the same figuring for the rest of the roof, l x w = sq ft
 

TommyK

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Don't forget to account for the starter course on the eave and rake and extra shingles for the ridge cap!
 

Spudland_Dave

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Don't forget to account for the starter course on the eave and rake and extra shingles for the ridge cap!

Do yourself a favor and get Starter Strip and Ridge Cap seperately as a standalone product. Dont do the "piece upside down" for the starter and cut all your own caps. Getting the right stuff is cheaper and WAYYY easier..

Figure out how many squares you need and buy plenty extra. Just return what you dont need. ESPECIALLY if its an odd color or something like that. Grits can vary from lot to lot...
 
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stitan06

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Thanks yeah I know starters and ridge cap that I all know I also know what I need for the whole roof only thing I was confused on was how to fig valleys and the area of the porch part the bottom is maybe 4 ft and the top 10 ft or so I read some on the internet just fig there might be some more experienced roofers on here thanks for any and all help

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Steevo

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Thanks yeah I know starters and ridge cap that I all know I also know what I need for the whole roof only thing I was confused on was how to fig valleys and the area of the porch part the bottom is maybe 4 ft and the top 10 ft or so I read some on the internet just fig there might be some more experienced roofers on here thanks for any and all help

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If you could clarify what you are trying to share here, maybe with a diagram, it would help us help you.
Based on what you wrote above, I am guessing that you have some areas that are not rectangular, and don't know how to calculate the square footage of them.
Post a picture or two, and make it more clear what you are asking, and there will be plenty of help here.
 

RECox286

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OK, we all have to start someplace. You do roofs for a living. Ask the boss

if he will let you figure some jobs, or if he will help you figure some jobs.

You can talk to him about maybe expanding the business, putting you in

charge of a crew now and again. Make it sound as if it were going to be

a good thing for him. It's a thought. We had more than one job going at

a time, so I know what it means to have a guy you can trust.

Uncle Bob
 

NUTTSGT

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OK, we all have to start someplace. You do roofs for a living. Ask the boss

if he will let you figure some jobs, or if he will help you figure some jobs.

You can talk to him about maybe expanding the business, putting you in

charge of a crew now and again. Make it sound as if it were going to be

a good thing for him. It's a thought. We had more than one job going at

a time, so I know what it means to have a guy you can trust.

Uncle Bob

Good advice to ask the boss, he can show exactly what he's doing.
 
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stitan06

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No I dont do roofing I work at a cemetery we do all our own maintenance and building . I fig pics would help and yes the areas im asking about are not square thats how why im kinda confused .

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BWS

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Unless theres a reason that you have to figure it "tight"....and there may be.

Whats wrong with running back to shingle store and gettin a sq or so to finish?
 
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stitan06

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Nothing actually im gonna order for my shed roof also . so I will have extra im not that worried about it I just ask

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hockey88fan

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Do yourself a favor and get Starter Strip and Ridge Cap seperately as a standalone product. Dont do the "piece upside down" for the starter and cut all your own caps. Getting the right stuff is cheaper and WAYYY easier..

Figure out how many squares you need and buy plenty extra. Just return what you dont need. ESPECIALLY if its an odd color or something like that. Grits can vary from lot to lot...

This ^^^
 

santagary

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No I dont do roofing I work at a cemetery we do all our own maintenance and building . I fig pics would help and yes the areas im asking about are not square thats how why im kinda confused .

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Stitan, thanks for your courage in asking a question about a topic outside of your experience and expertise! There are no silly or stupid questions, just silly, stupid, judgmental and smart *** critical answers. Good on you for enduring the criticism....that's what this and all forums are about! :thumbup:
 

spy604

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To calculate triangular areas, if one corner is a 90 deg angle measure each side off of the 90, multiply, then divide by two.
For example, starting at the 90, one side is 12' and the other is 15'
12 * 15 = 180 / 2 = 90 sqft

Just divide up the roof into rectangles and triangles and you should be able to calculate it.
 

NUTTSGT

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No I dont do roofing I work at a cemetery we do all our own maintenance and building . I fig pics would help and yes the areas im asking about are not square thats how why im kinda confused .

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"not square"


The term square (sq) when used in roofing refers to 100 square feet. 100 square feet are normally covered by 3 bundles unless you are buying a higher dollar designer or architectural shingle. So if somebody tells you that they need a square of shingles, they need 3 bundles.

It has nothing to do with the roof being a true square (all four sides the same), rectangle or triangle.
 
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Spudland_Dave

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Where will you be buying your shingles? If you go to Home Depot or Lowes, your on your own....but I know if I had a sketch of what I was trying to do, my lumberyard would do all the calculations for me. I know they did all the calcs for ALL of my materials on my garage... Works good in 2 ways...they know what product your looking for and will calculate accordingly (as mentioned some shingles are not 3 to a Square) AND if they short you or over you, they are always good to help. They calculated me 3 sheets short on my roof sheathing..when it looked like we were short I made a call and they apologized many times and sent a guy literally right over..I lost no time.
 

barks

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This discussion was missed by Abbott and Costello when they did "Who's on First". The 'square' discussion would have provided all the material needed.
 
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stitan06

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thanks we looked at home depot and liked a shingle there. i have seen some roofing supply places around im gonna try and see if you need an account with .
 
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stitan06

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To calculate triangular areas, if one corner is a 90 deg angle measure each side off of the 90, multiply, then divide by two.
For example, starting at the 90, one side is 12' and the other is 15'
12 * 15 = 180 / 2 = 90 sqft

Just divide up the roof into rectangles and triangles and you should be able to calculate it.

the " old man " who i work with told me kinda the same thing i just wasnt getting it. i trust in what he said and how to do it hes worked for them for 41 years and has done most of there building . just thought there may be an easier way i would understand this helped
 
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stitan06

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I guess no one reads books anymore.

if i didnt like to read i would have not become a member here to sit and READ all of this. i read about stuff i have no use for just to read and learn about diff stuff
 
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stitan06

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Stitan, thanks for your courage in asking a question about a topic outside of your experience and expertise! There are no silly or stupid questions, just silly, stupid, judgmental and smart *** critical answers. Good on you for enduring the criticism....that's what this and all forums are about! :thumbup:
well thats what forums are about asking other ppl that know more about on subject than others. i can put the shingles on and do all the grunt work thats what i do its the other part im fuzzy on ppl have helped me here
 
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stitan06

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yeah im fortunate enough to live on the back side of where i work. and have full access to all there equip when i want we have a skidloader with forks on it so not caring anything up the ladder thats to hard. WORK SMART NOT HARD
 

jwhcars

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You work in a cemetery and I bet people are just dying to get in.
I hear its a dead place to work.

Sorry I couldn't resist.
 

NUTTSGT

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I never thought that carrying shingles up a ladder was that hard. :dunno: Now stepping off the roof (with a bundle) onto the ladder, I'd rather throw the bundle to the ground.
 
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stitan06

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I here those a lot im used to it lol . I agree not hard caring up either down diff story . 5 gal buckets of rubber roof glue ***** to take up and down ladder . Like I said before we do all our own work I have learned a lot since working at this job . Before this job I worked as a hvac installer so now having a house I dont have to hire anyone to do anything saves me a lot of money

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boiler7904

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Unless theres a reason that you have to figure it "tight"....and there may be.

Whats wrong with running back to shingle store and gettin a sq or so to finish?

Color can vary greatly from one production run to another in any man made building material - tile, roofing, carpet, etc. Always buy enough to finish the job with some left over for future repairs. I'd rather return 10 or 15 unused bundles than be 10 or 15 short.

When my house was built 7 years ago, I couldn't get the builder or roofer to leave an extra bundle or two for me. A year later, we needed to have a 4' x 4' section of sheathing replaced and re-roofed - it was a PITA for them to find shingles that matched my roof but they finally did after 2 or 3 weeks.

Been down that road with tile and carpet on commercial construction projects too where the sub didn't order enough and we had to separate the material by production run for different rooms, keeping a few pieces of each run for future repairs.
 

sophijo

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Color can vary greatly from one production run to another in any man made building material - tile, roofing, carpet, etc. Always buy enough to finish the job with some left over for future repairs. I'd rather return 10 or 15 unused bundles than be 10 or 15 short.

When my house was built 7 years ago, I couldn't get the builder or roofer to leave an extra bundle or two for me. A year later, we needed to have a 4' x 4' section of sheathing replaced and re-roofed - it was a PITA for them to find shingles that matched my roof but they finally did after 2 or 3 weeks.

Been down that road with tile and carpet on commercial construction projects too where the sub didn't order enough and we had to separate the material by production run for different rooms, keeping a few pieces of each run for future repairs.

....same with brick BTW.
 

RECox286

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Not to be ignorant, but this is where high school geometry class

is supposed to click in. Break the roof into easy to figure "pieces"

add them all together, add 10% for waste.

I have found it pays to use the heaviest (measured by year) overlay

shingle, Ice and Water Shield, 30# felt, starter strip, and real double

dipped galvanized (not zinc plated) nails. Also, do not use the flimsy

rubber stack flashings, instead get a tinbender to make up copper

stack flashings that you can curl into the stack. For valleys, if you

can't afford copper, next best thing is painted aluminum coil stock

(painted both sides) as wide as can be had, and put down first on the

bare roof deck, entirely covered over with felt. "The roof shingle should

only be there to make the roof pretty, while everything underneath should

be there to keep the water out" is a good way to build a roof that will

stand the test of time. There should be How-To books at the big box

store, or at the bookstore that will help you out.

Good luck

Uncle Bob
 

aabirdman

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Don't worry about "bundles" Just go by square footage. Add at least 5-10% for cuts an loss. if its a hip roof add 10-15%. nothing like being short the lass row or two.
 

csp

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the " old man " who i work with told me kinda the same thing i just wasnt getting it. i trust in what he said and how to do it hes worked for them for 41 years and has done most of there building . just thought there may be an easier way i would understand this helped

Draw a rectangle on a piece of paper of lets say 4" by 10". Total area is 40 square inches.

Now draw a line from one corner to the opposing corner. What do you have now? Two triangles that are each 1/2 of 40 square inches.
 
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stitan06

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thanks guys all this is helping i forgot on of the guys i work with has autocad and is gonna fig it up that way but im gonna try myself see how close i get
 

BWS

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3 completely different ways to run valleys......All 3 take different amts of shingles.

Yes there are lot numbers......yes theres colour changes....Heck,install your roof and throw some "leftovers" up there a cpl years down the rd and see how bad the originals faded.Whatcha gonna do now....

I'd see how big a pile the supplier has....and still,get them to bring what I thought would do the job.Then simply go back in a day or so and snag another sq.

Been puttin roofs on for 40+ years....it ain't rocket science.Good luck.
 

JimVonBaden

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Stitan, thanks for your courage in asking a question about a topic outside of your experience and expertise! There are no silly or stupid questions, just silly, stupid, judgmental and smart *** critical answers. Good on you for enduring the criticism....that's what this and all forums are about! :thumbup:

I agree. I am also interested in this subject as I intend to add a workshop to my garage in a couple years. I think asking these types of questions is good for everyone.

Jim :cool:
 
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