How to Install a Slate Roof: Insights from a Winfield Roof Installation Company

Installing a slate roof requires advanced knowledge and skills. Below, we’re going to discuss how to install a slate roof for your Winfield, Illinois home:
1. General Working Practices3
Do not walk on the slates during installation. Always work off roof ladders and roof scaffolds. This is to avoid slipping slates, i.e., slates that break or fall off after installation.
Chalk your slates. Install every slate along a permanent chalk line on the surface of the roof. Do not chalk on the slates themselves. The lines mark the top edges of the slates. Measure where to put your line from the bottom of the roof to ensure accuracy and consistency. Do not lay the slates without chalk lines, as you can easily lose your headlap and ruin the roof.
2. Starter Slate
The starter slate is one of the most important shingles on a slate roof. First, nail a wooden or copper cant or shim under the bottom edge of the starter slate so that it’s at the same angle as the other slates.
Install the starter slate, and the first shingle of field slates at the same time. Do not run the starter slates ahead of the first shingle unless your starter slates are the same width as the field slates and only have nail holes on the top edge. This way, you will have correct side laps and ensure that no nail holes in the starter slates in the joint between the first course slates can create a leak.
3. Side Laps
Make sure you create the correct side laps, i.e., the lateral overlaps between the side butts of the starter slates and the first course of slates.
4. Headlap
Every slate needs to overlap the two shingles below, and it’s important to ensure that you install the correct headlap to keep the roof watertight.
5. Underlay
Slate underlay should always be installed.
6. Ice-damming
Slate roofs do not need an ice and water membrane. If you’re concerned about ice-damming, you may want to double the amount of decking felt along the eaves. You can spread roof cement between the layers and increase the headlap along the eaves to 13 cm.
7. Slate Nailing
It’s important to get your nailing technique right, or you could damage to the slates. Nails should only be driven to a depth where the nail head lies within the counter-sunk nail hole crater. Doing it correctly will ensure that the nail heads will not rub excessively against the overlying slates and wear a hole in them.
Do not over-nail or under-nail the slates. Over-nailing means the nail is driven too far and breaks through the slate. When the nail is sticking out of the nail hole, this is known as under-nailing.
8. Flashings
It’s important that you install flashings with the correct overlap, or they will leak. Corner flashings must either be correctly folded or soldered to prevent leakage.
Folded flashings can be used on positive slopes, whereas soldered flashings are required when the slope is so low that the direction of the water flow cannot be controlled by gravity alone. Soldered flashings need to be installed with cleats or expansion joints to prevent strain on the solder joints.
9. Hips and Ridges
Make sure the field slates meet tight at the roof hip and form a straight, weather tight, close-mitered junction.
Professional Slate Roof Installation in Winfield, IL
Installing a slate roof may be slightly more difficult than installing other types of roofs. However, as long as you hire an experienced roofing contractor in Winfield, Illinois, they will be able to successfully install a slate roof on your home. If you want to leave your roof installation in the hands of licensed roofing professionals, contact us today!