Because of the way floors are made lifting a floorboard is not always as straightforward as it may appear. Older houses usually have square-edged boards. These are not too difficult to lift, although some force may be needed.
Square-edged floorboards
To lift these check the surface of the board to see if it is secured with nails or screws; the screw slots may be filled with dirt so look carefully. If it is held with screws. the board will con-re up easily once the screws are removed; if nailed. it must be levered up. Start near the end of a conveniently placed board and insert a strong lever such as a long cold chisel, car tyre lever or flooring chisel into the gap between the boards. Hammer the chisel to prise up the end until another lever, for example a claw hammer, can be inserted under the board.
Work the two levers along the board until it is free. Alternatively. put a batten under the board. resting on boards either side, and hammer it along to avoid splitting the board or marking the next. Another method is to slip a length of steel pipe or rod under the end which has been lifted. Stand on the loose end and the leverage of the rod will force up the board further along its length. Keep moving the rod forward until the entire board comes up.
Tongued and grooved floorboards
The tricky part of lifting these boards is getting the first one up. Once this is out of the way the others can be lilted quite easily. To test for a tongued and grooved floor. take a thin-bladed tool, such as a screwdriver, and try to push it between the boards in several places. If the floor is tongued, you will not be able to insert the blade more than about 6mm . The best way to cut through the tongue (to release the board) is with a flooring saw, which looks like a tenon saw with a convex curved cutting edge. Cut right along the joint on one side and lever up the board as before. A circular power saw will cut through the tongue, but it makes a wide cut which may not be acceptable if the surface of the floor is to be left exposed. You can use a small pad saw, but take great care not to cut through electric cables and water pipes under the floor. To be on the safe side, tum off the electricity and the water. Cut with the blade at a shallow angle and use the tip to feel for cables and joists (which should be evident by the lines of nail heads).
Chipboard panels
Modem homes may have floors of tongued and grooved chipboard panels, which are very difficult to lift. The best way to remove an entire panel is to saw round the joints on all four sides using a powered circular saw with the blade set to cut 19mm deep. If this does not allow the panel to be lifted, increase the depth of cut to 22mm in case thicker panels have been used.
Cutting across boards
If there is not a convenient cut end at which to start lifting the board, make a cut across the board close to a joist. Look for the nail heads and use a thin blade to feel for the side of the joist. If you cannot get a blade between the boards, estimate the joist will extend 25-38mm on either side of the nails. Mark with a pencil a line across the board to one side of the joist. Drill three or four small holes at an angle away from the joist, just inside the pencil line, to enable you to insert a saw blade.
Using a pad saw or powered jig saw cut across the board , keeping the handle of the saw tilted towards the middle of the joist so the board will be supported when it is replaced. Give the board some additional support when you replace it by gluing and nailing a piece of scrap wood (50x25mm) to the side of the joist with clout nails 38mm long so its top is flush with the top of the joist.