Floorboards suffer more from being lifted for access to pipes and cables beneath them than they do from everyday wear and tear. If the floor has nothing worse than the occasional creak, the trouble can generally be cured by lifting floor coverings and then nailing or better still, screwing the offending board down again. With a chipboard (particle hoard) floor, make sure that the boards are nailed to even joist the cross, not just at the edges; if they are not, the boards can bow upwards and will then hang against the joists when walked on.
Before lifting a section of floor to gain access to services below it, look first of all to see whether someone has already cut an access panel. If they have not, it will be necessary to create one. Locate the joist position closest to where access is needed the positions of the flooring nail will reveal its whereabouts. Then drill a starter hole and use a power jigsaw (saber saw) to make a 45° cut next to the joist. Rise up the cut end and wedge a strip of wood underneath it, then saw through the board over the center of the next joist to free the section. To replace it, nail one end to the joist and either skew nail (toe nail) the other angled end to its neighbor or nail a support block to the side of the joist and nail or screw the board end to that.
With a concrete floor, the only repair that is likely to be needed is the filling of cracks or small potholes that may be revealed when an old floor covering is lifted. Cut back any loose edges, brush away loose material and fill the cracks with a fine mortar mix. If the floor surface is sound but uneven or out of level, lay a self-smoothing compound over it.
Creating an Access Panel
- Start by locating an adjacent joist. Drill a starter hole for the saw blade. Cut through the board at 45° next to the joist with a power jigsaw (saber saw).
- Use a bolster (stone-cutter’s chisel) or a similar broad-bladed levering tool to rise up the cut end of the board and release its fixing nails.
- Slide a length of scrap wood under the raised end of the board to hold it clear of the floor, and saw through the board the center of the next joist.
- To replace the panel, simply lay it back in position. Nail the square-cut end to its joist and skew nail (toe nail) the angled end to the neighboring board.
- An alternative way of supporting the cut ends of an access panel is to nail small woodblocks to each side in the adjacent joists.
- You can also screw down the panel on to the wooden blocks. This will allow easy access without damaging the panel.
Repairing a Concrete Floor
- If you discover cracks in a concrete floor after lifting old floor coverings, use a cold (box) chisel and club (spilling) hammer to undercut the edges of the crack.
- Brush away all loose material from the crack and use a vacuum cleaner to pick up the dust.
- Dilute some PVA building (white general-purpose) adhesive, and brush it along the surface of the crack to help the repair mortar to bond to it securely.
- Mix up some pack-setting repair mortar and trowel it into the crack, leveling it with the surrounding concrete. Leave it to harden.
- If the floor has noticeable potholes in its surface, pack the hole with some small pieces of stone or other non-compressible filler.
- Patch the pothole with quick-setting mortar, using the edge of a steel float to remove excess mortar so that the patch is flush with its surroundings