# Cutting asphalt shingles



## dielectricunion (Feb 27, 2013)

I know this is an incredibly basic question but what do you use when face cutting asphalt shingles?

I just cut a gas vent into my roof at home and used a fresh blade on a standard razor knife. It wasn't easy to keep the blade from wandering all over the grit and took a lot of passes.

Just wondering if you guys who deal with this all week do anything different or maybe I just need to learn to use a razor knife!


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## Inner10 (Mar 12, 2009)

Roofer's knife.


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## Texas Wax (Jan 16, 2012)

Circular Saw (preferred) or sawzall ... get everything in one shot :whistling Not mother approved tho, but time tested :clap:

Gas vent ? You mean sanitary vent correct?


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## Warren (Feb 19, 2005)

A hook blade will fit into a standard utility knife. Makes a big difference.


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## jb4211 (Jul 13, 2010)

I would buy a cheap circ saw and use that. The asphalt heats up, gums up and makes a mess out of a good saw.

I made that mistake and had to use gasoline and about an hour or so to get mine clean.


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## jlsconstruction (Apr 26, 2011)

Hook blade, or hole saw


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## skillman (Sep 23, 2011)

Be Carefull with those hook blades . They like fingers and I got stiches from that bad boy .


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## dielectricunion (Feb 27, 2013)

Texas Wax said:


> Circular Saw (preferred) or sawzall ... get everything in one shot :whistling Not mother approved tho, but time tested :clap: Gas vent ? You mean sanitary vent correct?


Haha, not that kind of gas. I mean a B vent and flashing for my furnace and water heater. Used to have a brick chimney, which literally collapsed!


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## jb4211 (Jul 13, 2010)

dielectricunion said:


> Haha, not that kind of gas. I mean a B vent and flashing for my furnace and water heater. Used to have a brick chimney, which literally collapsed!


A small hole, hook blade


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## Walter Secore (Jun 2, 2012)

A old pair of tin snips. Works great and will work for years. As I yell down to the grunt where are my shingle sheres


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## TimelessQuality (Sep 23, 2007)

:thumbsup:


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## Tom M (Jan 3, 2007)

I use dull siding shears for dimensional. Hook blades for regular.


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## skillman (Sep 23, 2011)

Tom M said:


> I use dull siding shears for dimensional. Hook blades for regular.


 Shears are great for cold shingles .


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## shanekw1 (Mar 20, 2008)

X 4 or 5 on the hook blade.

X2 on they will rip stuff out from deep in your finger or hand if you get them in the way.


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## Randy Bush (Mar 7, 2011)

For sure hook blades and old pair of siding snipes.


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## hdavis (Feb 14, 2012)

dielectricunion said:


> I just cut a gas vent into my roof at home and used a fresh blade on a standard razor knife. It wasn't easy to keep the blade from wandering all over the grit and took a lot of passes.


Drill a pilot hole to get a blade through and sawzall out. Then it's just a minor trim for the boot. Hook blade for fitting the boot. If I'm not wearing gloves, I usually wish I did.

If I'm cutting a rake edge, I have a cheap circ saw with demo blade that I use for demo and cuts like this one.


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## 1985gt (Dec 10, 2010)

Probably should call in a professional. :whistling


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## Red Adobe (Jul 26, 2008)

hook blade or the cheap "double cut" saw ( 2 4" counter rotating blades ) I bought it just for roofing work


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## hdavis (Feb 14, 2012)

Red Adobe said:


> hook blade or the cheap "double cut" saw ( 2 4" counter rotating blades ) I bought it just for roofing work


How is the double cut working for you? I noticed Harbor Freight has a cheap one.


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## Tom M (Jan 3, 2007)

I can't believe people use a circular saw to cut roof edges.


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## jb4211 (Jul 13, 2010)

Tom M said:


> I can't believe people use a circular saw to cut roof edges.


I have. Worked great


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## Tom M (Jan 3, 2007)

With dimensional, I run a soldier course up the edge and use it as a guide for my shears. I cut and fill in the steps as I go. The clean cut gets used on the next row. Nice waste.


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## Mr Latone (Jan 8, 2011)

dielectricunion said:


> I know this is an incredibly basic question but what do you use when face cutting asphalt shingles?
> 
> I just cut a gas vent into my roof at home and used a fresh blade on a standard razor knife. It wasn't easy to keep the blade from wandering all over the grit and took a lot of passes.
> 
> Just wondering if you guys who deal with this all week do anything different or maybe I just need to learn to use a razor knife!


Use a straight blade to cut shingles from the back (non granular) side. All it takes is a decent score and a fold and the shingle comes apart. Laminates may require a second score to cut the second layer

Use a hook blade to cut from the granular side. They behave a lot nicer if they are warm from the sun.

An old pair of tin snips do work very well, particularly on cold or very heavy laminates. Something like a well worn and somewhat loose pair of Malco MC-12 work great, but even an old pair of aviators do the trick. Once you start to cut shingles with them their metal cutting ability quickly diminishes.


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## KennMacMoragh (Sep 16, 2008)

dielectricunion said:


> It wasn't easy to keep the blade from wandering all over the grit and took a lot of passes.


Flip the shingle over.


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## Calidecks (Nov 19, 2011)

I use my roofer


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## Red Adobe (Jul 26, 2008)

hdavis said:


> How is the double cut working for you? I noticed Harbor Freight has a cheap one.


It works great on all roofs so far to cut thru.... its like working with a cutoff wheel on a grinder except no kick back

I thought we was talking about making a hole in a roof not trimming edges


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## dielectricunion (Feb 27, 2013)

Hopefully I won't have to mess with another roof for a while, but when I do, I'll get some hooks and my beater snips. Thanks!


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## ZachNewberry (Oct 1, 2014)

I like to use my hook blade on warmer shingles. I break out the all purpose snips in the morning or when its cold to save my pretty knuckles and hook blades!


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## flippinfool (Jan 6, 2009)

Tom M said:


> With dimensional, I run a soldier course up the edge and use it as a guide for my shears. I cut and fill in the steps as I go. The clean cut gets used on the next row. Nice waste.


:thumbup:

I also use a shingle shear for starters and fill course.


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## muskoka guy (Nov 16, 2013)

Maybe I am missing something here, but how do you cut in a vent with a skil saw through the shingles. Don't you need a flashing boot tucked up under the shingles above it. I have installed plenty of plumbing vents and chimneys ect. I generally use a flat bar and remove a few shingles in the area where the penetration is. I then cut the hole through the plywood with either a cordless skilsaw or sawzall, then install the boot onto the lower shingles. Reinstalling the removed shingles is basic, just cut around the boot putting the upper shingles on top of the flashing boot. Cutting the shingles is easily done from the face with a hook blade as shown or turn them over and cut them with a standard razor knife. Tar any exposed roof nails on the lower edge of the boot.


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## Roofcheck (Dec 27, 2011)

Shingle Shear all starter rakes. 8 +/- off a shingle leaves 31 +/- and then 16 +/- leaves 24 + / -


Full shingle, 31, 24, 16, and 8. Cut two at a time makes fast clean rakes. \


Use hook blades to cut around pipes or mark and shear.

I never cut shingles with a circular saw. Ridge is cut when there is no paper on the deck. Doesnt make any sense to do it after.


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## dvdrobb (Dec 10, 2013)

Right, and not only on the rakes, but valleys as well, that blade must affect the integrity of the shingle


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## hootrod351 (Jul 3, 2013)

mostly a roofers knife. ill also use tin snips around pipes, dimensional shingles, bought the rigid air shingle cutter and have to say in the winter its sweet for cutting valleys.


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