Installing metal roof tiles: the steps, the batten spacing and what not to do

Metal roof tiles are installed on timber battens of 25×50 mm, set 350 mm apart, on roofs with a pitch of at least 14°. First come the gutters and the flashings that collect the water, then the anti-condensation membrane and the battens, then the tile sheets, from the eaves towards the ridge. Below are the steps from the BELPROFILE installation principles, in the order in which they are done.

What to check before installation

• The roof pitch. BELPROFILE metal roof tiles are installed from 14°, that is 25%.
• The length of the sheets. The length of the roof is measured between the eaves line and the ridge line, and the sheets are ordered as a multiple of the length of one module, 35 or 40 cm.
• The angle between the eaves and the gable. It is measured before the first sheet. Where the edge and the eaves are not perpendicular, the verge underflashing takes the water from the edge.

How far apart are the battens set for metal roof tiles?

350 mm apart, measured from one batten to the next. This is the batten spacing of all five BELPROFILE models: Nordic, Royal, Riviera, Sierra and Monaco. The battens are timber, with a section of 25×50 mm.

Can metal roof tiles be installed without battens?

The BELPROFILE installation principles specify battens. They hold the sheets at the step of the profile and leave the gap under the metal through which the air circulates, from the eaves to the ridge. A metal roof is installed as a ventilated build-up: anti-condensation membrane, ventilation gap and air circulation. Without this gap, condensation stays under the metal and on the timber.

The order of installation

1. The gutters and the eaves flashing. The components that collect the water are installed before the tile sheets. The eaves flashing goes on the timber board that supports the gutters, after they are installed and before the anti-condensation membrane, with an overlap of 5 cm over the gutter.
2. The anti-condensation membrane and the battens, at 350 mm.
3. The valley, at the junction of two roof slopes. It is fixed with clips; drilling it is forbidden.
4. The verge underflashing, on the edges of the roof, after the eaves flashing and before the tiles. It takes the water from the outer sides of the roof.
5. The tile sheets. They are laid from right to left, starting from the bottom.
6. The verge trim, over the tiles and over the board that borders the roof (the fascia board). It is fixed with self-drilling screws, every 70 cm.
7. The ribbed ridge. It is fixed with self-drilling screws at the points where it touches the tile sheets. The ridge end caps close its ends and are perforated, for the ventilation of the roof.
8. The snow barriers and the snow guards. The snow barriers go on roofs with a steep pitch, 70 cm from the bottom edge of the roof. The snow guards are installed in a triangular pattern, so that they gradually break up the sliding snow.

What are metal roof tiles fixed with?

With self-drilling screws. The 4.8×35 mm ones fix the sheets to the battens. The 4.8×20 mm ones fix the sheets to one another and fix the accessories to the sheets.

What are metal roof tiles cut with?

With metal shears, electric or hand. Cutting with an angle grinder is strictly forbidden: it burns the coatings that protect the metal, and the edge rusts. The filings left after cutting are removed with a soft brush. Scratches and cut edges are covered with touch-up paint, only locally: on large areas, differences in colour can appear.

How are the sheets transported and stored?

• On wooden pallets, so that the sheets do not bend or get knocked.
• In dry, ventilated spaces, protected from sun, damp and aggressive substances: acids, salts, wet concrete.
• At most three pallets one on top of another, of 150 sheets each.
• Outdoors, only temporarily: at most 72 hours, on a surface inclined by at least 10°, covered but ventilated.
• The sheets are pulled onto the roof on two beams set as an extension of the battens, down to the ground.

What tools are needed?

Spirit level, tape measure, carpenter’s pencil, power screwdriver, seaming pliers, electric jigsaw, hacksaw, metal shears and Teflon mallet.

In short

A pitch of at least 14°, 25×50 mm battens at 350 mm, the water-collecting flashings before the sheets, the sheets from right to left and from the bottom up, cutting with shears only. The steps are those in the technical data sheet of each model, which can be downloaded from its page. For the parts your roof needs, see the accessories for metal roof tiles or request a quote: the advice is free.