Plasterboard Jointing & Finishing | Video 4

Video 4: JOINTING AND FINISHING PLASTERBOARD

WHAT YOU WILL NEED

USG Boral Total Joint Finish
USG Boral Paper Jointing Tape

TOOLS

150mm & 100mm broad knives
200mm broad knife or plasterer's trowel
Corner tool
150-grit sanding sheet & hand sander
Soft sanding block for small patches
Dust mask
Eye protection

JOINTING PLASTERBOARD

  1. 1.Ensure that any adhesive holding newly installed plasterboard is completely dry, then remove any temporary fixing blocks (walls) and screws (backblocked ceilings).
  2. 2.Measure the lengths of paper tape you'll need for each joint.
  3. 3.Fill the joint recess formed by the recessed edges of the plasterboard using Total Joint Finish and a 150mm broad knife.
  1. 4.Place the paper tape along the centre of the joint and press it into the compound using the broad knife.
  2. 5.With the broad knife held at 45 degrees, draw it along the joint with enough pressure to remove excess joint finish and air bubbles. Leave enough compound under the tape to achieve a good bond.
  3. 6.Immediately apply a skim coat of Total Joint Finish over the top. This can reduce the possibility of the tape edge curling and wrinkling.
  4. 7.Allow the jointing compound to dry fully. Drying times are approximately 24 hours in normal conditions or 48 hours in cool conditions.
  5. 8.Apply a second, thin coat of Total Joint Finish approx. 200mm wide with the 200mm broad knife or plasterer's trowel. Feather (thin out) the edges of the coat to create a smooth transition between the joint edges and the plasterboard sheets.
  6. 9.When the second coat has completely dried, scrape or sand back any build-up of compound along the joint, for a smooth and level surface.
  7. 10.Then add a third and final coat of Total Joint Finish approx. 250mm wide, using either a 200mm broad knife or a plasterer's trowel, remembering to feather out the edges.
  8. 11.When thoroughly dry, sand the joint lightly to a smooth finish with a hand sander held diagonally across the joint. Use 150-grit sandpaper and take care to sand ONLY the jointed areas and not scuff the surrounding plasterboard.

HELPFUL TIP!

Try and avoid butt joints, which is where two sheets of plasterboard join end to end. But if they're unavoidable, refer to the USG Boral Plasterboard Installation Manual for the correct procedure for finishing them.

FILLING NAIL AND SCREW-HOLES

Apply three coats of Total Joint Finish to nail or screw heads, at the same time as you finish the joints. Overlap each coat by approximately 25mm, and when each is thoroughly dry, sand lightly before applying the next coat. (A soft sanding block is ideal.)

SQUARE-SET WALL/CEILING FINISH & INTERNAL CORNERS

  1. 1.Apply USG Boral Total Joint Finish to both sides of the internal angle with a 100mm broad knife at approx 75mm wide.
  2. 2.Fold the joint tape along its centre crease and push it into the compound with the broad knife or a corner tool. Apply a skim coat of compound over the tape.
  3. 3.When completely dry lightly scrape or sand if required.
  4. 4.Then apply a finishing coat of Total Joint Finish, ensuring edges are feathered and lightly extended beyond the first coat.
  5. 5.When thoroughly dry, sand lightly to a smooth finish using 150-grit sand paper - taking care not to scuff the surrounding plasterboard.

MORE INFORMATION

Where your ceiling meets the wall, you have a choice of creating a square-set finish or installing cornice. Find out more about cornices.

EXTERNAL CORNERS

  1. 1.To finish corners which are covered with an external bead, apply a 150mm coat of Total Joint Finish to both sides using a 150mm broad knife, forcing it into the perforations of the metal.
  2. 2.When dry, lightly scrape or sand to a smooth surface.
  3. 3.Apply a second 200mm wide coat of Total Joint Finish with a 200mm broad knife or plasterer's trowel, making sure edges are feathered and smooth.
  4. 4.Allow to dry fully, then apply a third 280mm wide coat of Total Joint Finish, remembering to feather out the edges.
  5. 5.When thoroughly dry, sand lightly to a smooth finish using 150-grit sand paper, taking care not to scuff the surrounding plasterboard.

SAFETY FIRST!

  1. Ensure any ladders, scaffolding, trestles or planks you use are adequate and safe
  2. Read cautionary notes on all product packaging
  3. Wear safety gloves when using sharp tools
  4. Wear a dusk mask and eye protection when sanding
  5. We recommend you consult with a licensed electrician and/or plumber about any electrical wiring and/or plumbing requirements, prior to installing plasterboard

WATCH NEXT

Video 5: Installing a cornice

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