To remove excess heat under the roof deck during the summer and excess water vapor during the winter, proper ventilation should be installed.
Condensation can cause damage to the roof construction and the insulation. Therefore: a vapor barrier in combination with room ventilation should be installed.
Follow your shingle manufacturers’ guidelines and local building codes.
To ventilate the roof construction covered with bitumen shingles it is necessary to establish a ventilation gap between the insulation and the roof deck.
Roof construction ^
The roof construction is designed and constructed to provide a strong functional long lasting construction on which a perfect nailable covering can be applied.
Roof deck materials ^
The type, grade, thickness and installation of materials used for roof decks should correspond to the requirements of local building codes. It is very important to use moister stable material. In particular plywood and OSB must be exterior quality. The panels have to be fixed and nailed properly, too.
Application of the underlay ^
Underlays are inner roof coverings, which protect wood construction against bad weather conditions before and during application of shingles. It also provides a secondary protection shield against capillary (rising) rainwater, wind driven rain showers and melting water (= ice damming).
These bitumen-based membranes have the advantage that they will close tightly around the nail after penetration. This certainly benefits the water tightness of the roof.
Respect the individual application instructions and the requirements of the local building codes.
Chalk lines – visual guide lines ^
Chalk lines are to be considered as guiding lines or auxiliary lines, do not consider them as application lines. Use vertical guidelines to align cutouts and horizontal guidelines to align the row of the shingles.
The place of the chalk lines depends of the size and the type of the shingles.
Shingle application ^
Start out of the centerline of the roof, moving left and right with shingles of which the tabs have been cut off (= starter strip or use special made eaves plates.). Allow these shingles to overhang approx. 1 to 1,5 cm over the roof edge. On top of this the first course of complete shingles will be applied (make sure that the joints of this first course do not match those of the starter course below).
From the second course and succeeding courses, always cut off half a tab to the left or right (depending which side has been started from). The seventh course once again starts with a complete shingle. Always mix shingles from different bundles to avoid color blocks on the finished roof!
Use the correct size and grade of nails. Use zinc coated, galvanized or aluminum nails for corrosion protection or copper nails. Use the recommended number of nails per shingle. Place the nails according to the shingle specifications. Align the shingles properly to avoid exposing nails in the course below. Drive the nails straight.
The use of staples is forbidden.
Position of nails: 2,5 cm above cutout and 2,5 cm from the side of the shingle (throughout the underneath applied shingle).
|The use of shingle mastic |
Shingle mastic is a bitumen-based cement used to bond roofing materials. Also known as flashing cement or mastic. This material is generally applied to flashings where roof meets a wall, chimney, vent pipe or other vertical surface. It is formulated to resist flow at the high surface temperatures normally encountered in summer. The cement remains pliable at low service temperatures. In general shingles do not need to be extra hand sealed, but it is recommended for some types of shingles and in high wind areas (check national regulations).
|Hip and ridge coverage |
Always ensure that, when installing the ridge covering shingle tabs, the nails of the upper shingle course (on both sides of the ridge) are covered. If this is not the case, add another shingle course on that roof section. In cold weather conditions: always store shingles for ridge capping in a warm shelter to prevent the shingles from cracking when you bend them. Always install them against prevailing winds. Cut the ridge slates slightly tapered.
When applying a round tab strip shingle or a laminated tab strip shingle shingles, be sure to order rectangular shingles in matching colors to cover hips and ridges.
You can also use prefabricated hip/ridge plates to cover the hips and ridges. There is a self-adhesive sealant on the backside of the plate.
Roof details ^
» Open valley
» Woven valley
» Close cut valley (for slope > 23°)
» Flashing against chimney
» Curved windows, dormer windows, entry's, …
» Turrets, bells