Shingles made simple

Daniel Redfern of manufacturer Marley Eternit says that installing a timber shingle roof is not as hard as you might think, and offers a step-by-step guide

From summer houses and self- builds, through to holiday homes and heritage projects, the demand for a natural timber aesthetic means there is growing opportunity and demand for builders and roofers who can install shingles.

Although often thought of as a specialist roofing material, with the right tools shingles are actually very easy to fit and can be done by anyone who can fix roof tiles. However, the way that you install shingles and the type of ventilation required will depend on what type of underlay you use – non- breathable (traditional) or breathable (vapour-permeable).

This guide shows how simple it is to install shingles, using the ShingleFix staple system as an example, with two different underlay methods.

Step 1a: Non-breathable underlay with 25 mm eaves vent system

Install a continuous rafter roll, over a fascia ventilator and felt support tray, to direct airflow below the underlay into the roof space. Dress the underlay down to bottom edge of the felt support tray and fix using a self-adhesive tape. Then continue to install the underlay in the normal manner.

Step 1b: Vapour permeable underlay with 25 mm eaves vent system (batten space vent)

This method does not require a continuous rafter roll. Instead install the felt support tray first, and fix the over- fascia ventilator over the top to direct airflow into the batten space, above the underlay and below the slates. Dress the underlay down to the bottom edge of the felt support tray, behind the over- fascia ventilator and fix using self- adhesive tape. Then install the underlay in the normal manner.

Step 2a: Non-breathable underlay – battens

Non-breathable underlay does not need to be counter battened. The position of the first batten should be the batten gauge plus half the thickness of the batten. The batten gauge thereafter is based on the pitch of the roof.

Step 2b: VP underlay with counter battens

Vapour permeable underlay needs to be counter battened to allow ventilation of the batten space above the underlay and below the shingles. The position of the first batten should be the batten gauge plus half the thickness of the batten. The batten gauge thereafter is based on the pitch of the roof.

Step 3: Setting out

When setting out the first course, care should be taken to ensure there is a minimum overhang of 38 mm at the verge and either a 38 mm overhang at the eaves, or if a gutter is to be used, at least the centre line of the gutter. A double course is required at the eaves and a broken bond pattern should be maintained.

Step 4: Fixing

Shingles should be twice nailed or stapled. You can use a 31 mm x 1.8 mm silicon bronze nail or stainless steel ring shank nail, but it can be a much quicker method to use a product-specific staple with a Paslode gun. Fixings should be positioned 19 mm in from the edge of the shingle to avoid splitting and 38 mm up from the butt of the course above.

Step 5: Installation

As there will be no visible roofing batten during the installation, use a chalk line to highlight the batten position to aid nailing/stapling in the correct position. Ensure the broken bond pattern is maintained throughout the roof and a 5 mm gap is left between each shingle.

Step 6: Ridges

When you reach the ridgeline, you will need to cut the shingles to maintain the 125 mm gauge – the shingles can be cut with a handsaw or by using a Stanley blade to score them. A double ridge course is required at the start of both verges and these should be fixed with a 45 mm x 2.65 mm nail, due to the thickness of shingles underneath.

Step 7: Finishing touches

Use the same gauge as the shingles at the ridge to give a more uniform appearance. This means ridges may need to be cut when they meet at the central point. A site formed decorative finishing piece can be installed in the centre of the ridge where the shingles meet.

Daniel Redfern is marketing campaign manager – residential roofing at Marley Eternit