b'2.4 INSTALL: Primelok2.4.4.3 JOINING: CONCEALED JOINERWeathertex also provides the Primelok Concealed Joiner accessory. This concealed joining method requires a 9.5mm gap between the ends of each weatherboard in order to accommodate movement. The concealed joiner accessory provides a flashing at the rear to prevent water penetrating into the cavity. Check 1.4.5 Length of Wall Requirements when using concealed joiners as they are not permitted for use on continuous walls greater than 11m in length (for walls greater than 11m in length, consider using the Large Long Vertical Joiner accessory, or traditional joiners).For concealed joining using the Primelok Concealed Joiner accessory, primer must be removed from the weatherboard ends to ensureadequate long-term sealant bond strength.Sealant requirements:Durometer 25 or lessBest colourmatch to proposed top coatHigh quality flexible paintable polyurethane1.Remove primer from weatherboard ends to be joined, then clean these ends with sandpaper and remove any dust. Do not prime cut ends, leave as unprimed.2.Apply a release agent to the front face of the concealed joiner such as a sealant lubricant, or release tape. This ensures the sealant does not stick to the concealed joiner and only sticks to the weatherboard ends. Ensure this release agent is only applied to the to the front face of the concealed joiner and not where you want the sealant or paint to stick.3.Insert the unprimed end of the weatherboard into the concealed joiner. Rest the bottom edge of the weatherboard on the base and lock into position under the top flange. The edge of the weatherboard should be in moderate contact with the centre nibs within the joiner. Do not force ends tightly together. The top flange will be hidden by the overlap of the weatherboard.4.Insert the unprimed end of the next weatherboard into the other side of the joiner against the centre nibs. Use a small offcut of 9.5mm thick Weathertex to set a 9.5mm gap between the plank-ends within the concealed joiner.5.Fasten the weatherboard to the wall at each stud in accordance with product requirements. Ensure nails do not pass through joiner and joins are staggered.6.Apply masking tape to board faces either side of join.7.Using a caulking gun, run a line of suitable, quality, highly flexible, paintable polyurethane sealant up the length of the concealed joiner, ensuring that the entire unprimed surface of each weatherboard end is completely covered with sealant. Always follow the sealant manufacturers application instructions. Ensure the chosen sealant has a durometer of 25 or less and the colour of the sealant is as close to the topcoat colour as possible. When using sealant, movement in the planks may result inFastener 15mm visible bulging or concaving of the sealant. In some cases,down from the such as where extreme changes in moisture have occurred,Concealedtop edgethe sealant may pull away from the board leaving a crackjoinerbetween the sealant and the board. This movement will not affect the performance or water tightness of the join, though it may be aesthetically displeasing. If this would cause an issue, Weathertex recommends the use of Traditional Joiners or the Large Long Vertical Joiner accessory.Release AgentSuitable sealantConcealed joinerWeathertex26'