by R. Haggerty

Created on: April 27, 2009

Before starting on any roofing project you must know the pitch of your roof. Roof pitches can range from a flat to very steep. Pitch in the roofing world is expressed in two numbers. The first refers to vertical and the second refers to horizontal. The number would is formatted like this, 4/12. That means that the slop of the roof is 4 units vertical for every 12 units horizontal.

It is important to know your roof pitch because not every roof product works on every roof pitch. A roof product could be the roofing material itself, a roof flashing used to seal around things penetrating the roof, a roof curb or skylight. The manufacturer of these products will be very explicit about what pitch of roof there product will work on. You will void a warranty if the product is installed on the wrong pitch.

Finding roof pitch is easily and you can do it it with tools you already have. 3 items you will need are: a right sized ladder, a 12" to 48" level, and a tape measure. This method assumes you are finding the pitch of a shingled roof.

Let's get started:

1) Select level solid ground to set up your right sized ladder safely so it does not tip over.

- Guys it is perfectly okay to ask your significant other to hold the base while you work, no one will think any less of you.

- Maintain a 3 point contact on the ladder that means always have 3 of your 4 appendages on the ladder as you work. Beer bellies don't count as an appendage.

- Keep your belt buckle within the rails of the ladder

- Never use the top step of the ladder. If you can't reach your target without having to use the top step, your ladder is too short. Take the time to go get another one. Again guys swallow your pride and ask to borrow your neighbor's ladder if you need to. Honestly we don't mind.

2) Pick a spot for your measurement

- The sunny side of the roof is the best place to do this. Moss can build up under shingle edges which could hinder an accurate measurement.

- Make sure your roof is solid and has no sags in it.

3) Break out your tools

- Put a mark on your level 12" from one end.

- Place the marked end of your level in the middle of a shingle, marked side down. Do not place the level on the edge of the shingle. Even shingle on the sunny side of a roof can get dirt and moss build up under them.

- Bring the other end up so the bubble shows level.

- At the 12" mark on the level, slide your tape measure down until it touches the roof.

- Note the measurement from the bottom side of the level to the roof.

You're done! Remember the vertical number is first the horizontal is second and that is typically always 12. Now you can confidently take that ladder back to your neighbor and tell him in as manly a manner possible "Yeah. I've got a 6/12 pitched roof. I thought it might be a 4 or a 5/12 but nope it's a 6/12. Got any beer?" It's always okay to borrow a beer.

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