How and why to use or snap a chalk line

What is a chalk line?

Chalk lines are the fastest way to mark straight guidelines on flat surfaces. They are used extensively in the building and construction industry to speedily and accurately ‘draw’ straight lines between two points.

Chalk lines are inexpensive tools, easily bought from your local DIY store. They can look slightly different but are essentially coils of string in a plastic casing or compartment. The casing contains chalk that is often purchased separately. When the compartment is filled with chalk, the string in the coil becomes coated in the chalk.

How to use a chalk line?

Using or snapping off a chalk line is simple. Here is a quick guide on how to do it:

1. Mark the two end points of the line you are trying to draw. You may need a measuring tape to set these points.
2. The end of the chalk line is tied to a loop or clip. Hammer a nail or drive a screw into one of the end points.
3. Hook the chalk line clip over the nail head or screw and reel out the string to the other end point along the straight surface.
4. Once you have the chalk line over the second mark, lift off the string and allow it to snap back onto the surface. The chalk will mark a straight line along the surface between the two points.

Get your chalk reel here.

Buy Red or Blue chalk in an easy-application flask.

Sometimes, you may not need to fix a nail or screw at the first mark. In that case, if you are working with a partner, simply asking them to hold the string at the mark will be adequate to ‘fix’ the string at the first end.

Chalk lines and roofing

You will probably make great use of your chalk line tool if you are installing your own roof, particularly when you are shingling. Straight lines will help you set and finish your roof correctly so be sure to include a chalk line in your kit list.

How to chalk line a roof for shingles?

If you have opted to take on the task of laying your own roof shingles, you will want to make sure that the shingles are laid out correctly along horizontal and vertical lines. (This is especially critical when your roof installation includes valleys, hips and gables). To do this you need to chalk out your horizontal and vertical lines prior to installing the shingles. Failing to properly mark out the lines where your shingles will go will lead to an improper and quite possibly an unattractive install.

Marking horizontal lines

To ensure the shingles are laid out straight and in line with your roof edge, you need to mark horizontal lines to guide where each course of shingles should go. To do this, start at the bottom edge of your roof and using a tape measure, mark the first lot of end points up the side of the roof. (Note, there will be variation in the way shingles should be laid depending on the brand and the type of roof you are installing, so be sure to follow the manufacturer’s instructions and recommendations). Do the same at other end, starting again, from the bottom. You should now have a series of end points on both side of your roof. Then, with the help of working partner, go up the side of the roof, and snap off the each of the lines.

Chalklines can be used for a variety of roofing projects.

Marking vertical lines

You will need vertical lines to guide you in correctly aligning your course of shingles to form a stepped or staggered look. (Again, there will be manufacturer instructions to follow as regards the placement of shingles and the recommended overlaps between adjoining shingles). To lay your vertical chalk lines, start as before by marking points first at the top of the ridge, and then at the bottom edge of the roof. Then go along the side of the roof, and snap of your vertical lines.

Once your lines are in place, you can begin to lay your shingles.

Taking the time to properly mark chalk lines will ensure a proper installation and an attractive finish on your roof, so do not miss this critical step.