In Southern England, the most common slate size is 500 x 250mm, and in the North of England and Scotland it is 400 x 250mm. Slate head lap

Electro-galvanized steel will eventually rust and will not last as long as stainless steel, but is a good choice for asbestos-shingle roofs or for a roof with around 25 years of life remaining. In centre-nailed slating, the gauge is the spacing at which the battens are fixed to the rafters, trusses or counter-battens to provide the required head-lap. The margin is the exposed length of the slate measured in the same direction as the gauge. The lap and margin will be the same. When opting for hook fixing method, it is important to know that hook fixings may not be suitable for large slates, which experience a greater wind uplift than smaller slates, and for pitches above 75º or below 25º. Slate hooks are available with straight or crimped shanks. However, crimped shanks reduce the capillary action and should be used for roof pitches below 30º. The method of using stainless steel point slate hooks is very cost effective which is why it’s an increasingly popular choice in the United Kingdom as well as across Europe. Because the slate is supported at four different points, these hooks can be used in even the most exposed locations without sacrificing resistance to wind uplift.The British Standard Code of Practice (BS 5534) specifies two ways of installing slates: nailing or hook fixing. These fasteners fix the slates to either batten, which is by far the most common English method, or to sarking board, which is commonly used in exposed areas in Scotland. Founded in 2004, Essex based Samac Fixings is a market leading distributor known for supplying nails, screws, rivets, fixings and slate hooks to a variety of specialist shops all over the United Kingdom. While they originally only offered nails, Samac Fixings currently boasts a wide range of nearly 6000 high quality products that are a favourite among merchants, builders, and contractors. When hook fixing, additional nail fixings should be used at eaves, ridges and top abutments and, to prevent lateral drift, at verges, hips, valleys and side abutments.

There are two type of Slate Hook, an over batten type and a drive in type. The use of over batten type is very limited with the majority being drive in type (shown in picture). With the hook fixing system, the slates are secured at the tail, thus providing strong resistance to wind uplift. To comply with BS 5534, hooks should be stainless steel, 18/10 or 316 (marine) grade, 2.7 mm gauge and at least 5 mm longer than the minimum lap required.

Features & Benefits: 100mm Bright Stainless Slate Hooks Point Driven - 316 Grade (Box of 500)

Nails should be copper (to BS 1202 part 2) or aluminium (to BS 1202 part 3). In corrosive or marine atmospheres copper nails are preferable and in severe conditions silicone bronze nails should be used. The nail head diameter should be at least 10mm to comply with BS 5534 to minimise the risk of the nail head pulling through the slate. A 10mm head is only possible where the nail shank is 3mm diameter or greater. There are a number of advantages and disadvantages which one should consider before using natural slate. On the plus side, natural slate has an aesthetic appeal and will stay looking good for many years. As such it may not need replacing. Other types of roofing slates such as concrete will lose colour and not wear so well visually, making slate more cost effective. The Hall Hook is a permanent, secret and fail safe device that should be used when replacing a broken slate. With a bright stainless steel coating for a purely decorative finish, this coating does not impact the corrosion resistance of the core material. The bright finish will typically last ten years or more unless in very abrasive settings for example salted winds.