Determine the length of your shingles from top to bottom. Shingles typically measure 1 foot, but the brand and style you are using may differ.
Shingles protect a roof deck from water damage and help prevent leaks. The shingles provide a water-tight barrier by overlapping layers. For the layers to correctly provide a leak-proof seal, the layers must be put on straight, ensuring that the next layer covers the nail holes and seams in the top of the last layer. From time to time, shingles will blow off or become damaged and need replacing. The shingles can be put on by the homeowner, but must be installed correctly, and straight.
Measure for the first row of shingles. The end of the shingle should overhang the eave of your roof by one inch. If your shingle is 12 inches from top to bottom, measure 11 inches. Measure at both ends of the roof, marking the point on both edges.
Hook the end of the chalk line on one edge, and carefully unspool the line down the length of the roof.
Pull the chalk line taut at the opposite edge of the roof. Place the line on the mark you measured on this end. Use a staple or tack to hold the line in place.
Snap the line every one to two foot the entire length of the roof. Simply pluck the line between forefinger and thumb and let go. When you have snapped the entire length of the line, you will have a straight chalk line the length of the roof.
Install the first line of shingles with the top of the shingle lined up on the chalk line. This ensures that the shingles are going on straight.
Repeat the process for each row of shingles remaining. Since these rows of shingles need to overlap the preceding ones, you will need to measure 10 inches up from the last chalk line with most shingles.
- “Measuring, Marking, & Layout: A Builder’s Guide”; John Carroll; 1998
- “Fine Homebuilding”; Laying Out Three Tab Shingles; John Carroll; August/September 1994
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