How to board out a loft

Summary: Learn how to lay loft boarding.

The first task is to inspect your loft to calculate how much insulation (assuming it is not already insulated) and chipboard you will need. Usually access into the loft is limited so make sure you have sufficient room to get your chipboard in before starting. If need be you might have to make the loft access bigger.

Boarding a loft

You should aim to buy 8'x 2' (2400mm x 600mm) lengths of water resistant floor grade chipboard. This is usually green in colour.

  • Lay your loft insulation to the required depth; see our insulating a loft project. Make sure you wear a mask, gloves and goggles to do this.
  • To work safely while boarding a loft use one or more lengths of chipboard as a mobile platform instead of trying to balance on the joists.
  • The chipboard is fitted directly to the joists, when boarding a loft ensure that the lengths of chipboard are laid at right angles across a number of joists and not laid astride. Laying the chipboard across the run of the joists will add plenty of strength.
  • Starting in one corner, first measure 8 feet along the joists (the length of your board). Undoubtedly it will not fall square on another joist so measure back to the centre of the next joist. Proceed to cut your chipboard ensuring that you are wearing your mask, gloves and goggles.
  • Lay the first board onto the joists making sure the tongue is nearest to you, i.e. furthest away from the wall. Screw the boards into place making sure you are not driving the screw anywhere near cabling or piping and that the screws are not closer than a couple of inches from the edge of the board.
  • Once the first board is secured, run PVA glue into the end groove of the next board. Push the second board flush with the first. Ensuring the joint is tight by tapping with a hammer. Complete the first row in this fashion, cutting each board to length as required.
  • The next row is begun by running the PVA into the full length of the groove on the first board before pushing it flush into the already secured first row board. Then simply carry on the same procedure with the rest of the boards remembering to run the PVA into the full length of the groove as well as the butt end of the board.
  • The final piece of boarding will probably need to be cut to size and forced into position with a pry bar.

When boarding a loft in this fashion you may want to consider cutting an access hole in one or more of the boards to allow easy access to cabling or piping.