ARCH FORMER INSTALLATION GUIDE
- The opening ready to receive an Expamet Arch Former. Where a previously plastered wall is involved, the plaster surrounding the opening should be cut back. This will result in a flush joint of new with existing plaster. Arch Formers are not designed to carry structural loads. A Lintel must always be used when forming new openings.
- The component parts ready for installation.
- Fix the first part on an Arch Former with masonry nails or plug and screw. The Arch nosing should be 13mm proud of the wall face to which it is being fixed.
- Lightly pinch the nosing of the arch over a cut galvanised nail (not supplied), which acts as a link between sections. If the pvc nosing is being used the arch former should be set back approximately 1mm from the angle bead to allow for nosing thickness
- Arch Former sections in position on both sides of an opening. A galvanised wire tie has been inserted to securely unite the Arch Former sections.
- Twisting the wire tie to secure it. The end of the tie is then bent inwards between apertures of the lath. Alternatively, self-tapping screws may be used.
- Start at the bottom junction, where the arch and angle bead should touch. Clip on the pvc nosing over the metal nose with guiding thumb pressure action. Work completely round the arch. Liquid soap can be used to aid application if required.
- A render coat of Thistle Bonding or Thistle Hardwall plaster should be applied to the Arch Former to a thickness of approx. 6mm from the surface of the lath. This should be deeply cross-scratched to key a floating coat of the same plaster. The floating coat should be ruled evenly to the Arch Former nosing and lightly scratched to key the finish plaster. Proprietary one-coat plasters now available can be used. Follow suppliers instructions.