Concrete ferrules are cast into the concrete panels to allow connections without drilling after installation. Threaded ferrules are often used for starter bars, steel connections and sometime props to hold the structures in place. The ferrules are cast in either face down or face up un the panel. If the ferrule is cast face down a ferrule locator will be required and if cast face up, a ferrule support chair will be normally used.

Concrete ferrules can be broken down into several key characteristics.

The material of the ferrule is made from solid steel or tube steel, solid steel offering the greater strength.

Solid ferrules have a thread that is drilled and then tapped where the tube ferrule is just tapped tube. There is also a course threaded ferrule that accepts a coil bolt which reduces the chance of clogged threads and increases installation time.

The solid ferrule can have a foot on the bottom of the ferrule to increase pull out loads where the tube ferrule can have a bent end. The footed ferrules have names like Qwikfoot (the old Klikfoot ferrule), Elephants foot and Big foot.

Coatings are zinc plated and hot dipped galvanised, the hot dip galvanised ferrule needs to be tapped after the plating process to clear the thread, so no coating on the inside of the ferrule. The galvanised ferrule will also have an oversized thread in most cases to accept a gal bolt.

Materials include mild steel, high tensile steel and stainless steel in several grades such as SS304 and SS316.

Sikaflex Pro from Sika Australia, Nitoseal PU250 from Parchem, Seal N Flex from Bostik Australia and Fulaflex 550PU LM from HB Fuller are flexible, durable, weather resistant low modulus, one part, elastomeric polyurethane joint sealants which all have excellent adhesion to a wide range of substrates and in some cases don’t require priming. These products cure using the moisture in the atmosphere.

Sika Pro is easily applied using a barrel gun or caulking gun and finish off nicely. Battery powered caulking and barrel guns are available for larger applications. Sika Flex Pro, Seal and Flex, Nitoseal PU 250 and Fulaflex 550 PU are one part or component product, so no mixing or mess.

Common uses include Construction joints between concrete precast panels and slabs, external wall and cladding joints, curtain walling, sealing around windows and door frames, retaining walls, brick work and block work.
When filling an expansion joint, backing rod is normally used. The two main reasons are to get the right shape or geometry and the other is to use less product. Backing rod is split into two materials, open cell polyurethane foam and closed cell polyolefin foam. These are available in round, square and rectangular shapes. We recommend round be used.

Each supplier has a number of colours, please refer to the colour Sika, Bostik, HB Fuller and Parchem colour charts

Cleaning should be done before the product is cured. Remove the bulk of the product using a scraper and then clean the scraper with the recommended cleaner. Cleaning your hands and skin will require a different product to your tools. Sika recommend Colma Cleaner for your tools and Sikaflex hand cleaner for your skin. Parchem you should use Fosroc solvent 10 for your tools, HB Fuller recommend Toluene, xylene, methyl ethyl ketone, acetone or mineral turpentine and a cloth and Bostik recommend their handy wipes.