BELGIUM - YOU DON’T HAVE YOUR VERTICAL SHINGLE CUT-OUTS STRAIGHT?
DO NOT WORRY... WITH THE “RANDOM SPACING” INSTALLATION METHOD YOUR ROOF WILL LOOK MAGNIFICENT ODD

Probably everybody has seen a roof with shingle cut outs not aligned vertically straight. It might happen when the length of roof shingles is different or when the roofing job was not done properly. The length tolerance of roof shingles is +/- 3 mm according to European CE norm and IKO roof shingles is the best performer in this range.

SO. LET'S START

As you know, the roof deck must be flat, firm, dry and securely nailed. Wooden deck can be made from plywood, OSB or wooden boards. The entire roof deck must be covered with proper underlayment which acts as a safety waterproofing barrier. Base flashings should be in place before the roof shingles are applied.
Sufficient chalk lines should be snapped to ensure accurate vertical and horizontal alignment of roof shingles.

For Superglass 3Tab shingles use galvanized 25 mm long roofing nails. The nail position is described below.

Prepare the starter by cutting off the tabs from a Superglass 3Tab shingle.

Cut half a tab from the 1st starter and nail down to the drip edge. Starters must be overhanged about 1 cm over the drip edge and sealed with mastic.
Random spacing can be achieved by removing different amounts from the rake tab of succeeding courses compared to classic installation method where there is removed ½ a tab.

You have to follow these general rules:
1.    The width of any rake tab should be at least ¼ a tab.
2.    Cutout centerlines of any course should be located at least ¼ a tab laterally from the cutout centre line in both the course above and the course below.
3.    The rake tab widths should not repeat closely enough to cause the eye to follow a cutout alignment.