How easy are they to fit?
One of the main benefits of fibre cement slates is that they are much easier to fix than traditional slates. They are man made and manufactured to uniform dimensions which means that instead of struggling to sort slates to consistent thickness and size, as would be necessary with natural slates, fibre cement slates can be easily and quickly installed on roofs with a pitch of 20° or above.
**Our Thrutone and Birkdale slates can now achieve a minimum pitch of 15° click here for further details**
Below is a simple step-by-step guide to fitting fibre cement slates:
Set out the roof battens by calculating the gauge using the formula below
Gauge = length of slate – lap required
Allow for the eaves courses of slates to overhang the fascia or tilting fillet so that the tails align with the centre of the gutter (approx 50mm).
Set out both under-eaves battens to accommodate the two lengths of under-eaves slates allowing for correct lap and gauge.
Cut the under-eaves slates from a standard slate and drill 2No 4mm dia. holes approximately 10-15mm in from the top cut edge and head nail the first under-eaves course along the eaves.
Cut and nail fix second under-eaves course to the lower eaves batten with slate and a half widths at the verge, ensuring a copper disc rivet is fitted centrally between adjacent slates (5mm gap) to align the pin with the hole in the front edge of the first course of full length slates.
Prior to fixing the slate and a half-verge slate, drill a 4mm dia. hole half a slate width distance in from the verge and 25mm up, to allow for the disc rivet to fix the first full slate course above.
At the verge, a second hole (4mm dia.) is required to allow for the copper disc rivet for the next course. This is drilled 50mm from the outside edge of the slate and 25mm plus gauge from the bottom edge, or tail.
Continue to lay the first course of full length slates, twice nailing each slate and inserting a copper disc rivet between adjacent slates aligned with the hole in the front edge of the slates above.
When the next course of slates is laid above, the rivet shank is passed through the hole in the front edge of the slate and the rivet shank bent 90° so that it faces down the roof slope to secure the tail of the slate.
At the verge a second hole (4mm dia.) should be drilled 50mm distance from the outside edge of the slate and 25mm plus the gauge distance from the tail to allow the disc rivet pin to be inserted for the next course above.
At verges and abutments, lay the first full length slate and a half slate, ensuring that 3No. 4mm dia. holes are drilled on the batten line with 2No. additional holes for the copper disc rivets.
For remaining courses, where single and slate and a half slates are used, a third disc rivet hole is needed to allow for the rivet pin for the next single width verge slate (at point C). This is drilled half the single slate width from the side of the slate and the 25mm plus the gauge distance from the tail.
Continue diagonally up the roof with standard size slates, trimming to verges, hips, valleys and ridges as required. Ensure all cut slates are placed with the edges adjacent to other slates and are not exposed. Slate and a half widths should be used if the half slate is less than 150mm wide.
At valleys and hips where slates need to be cut on the rake, wide slates must be used to maintain an adequate width and sidelap at the head or tail. At mitred hips on low pitched roofs wide slates should be used beneath the hip capping.
At the roof apex or top abutment, an additional top course batten is fitted directly above the last full length slate batten. The last full length roof slates / short courses are cut to length so that their top edges rest on the lower batten and are centre nailed as normal.
The top course slates should be cut to length and head nailed as per the under-eaves course slates with a disc rivet fitted to the tail.