Repairing Floors and Floorboards

In order to carry out simple repairs to floors of different kinds the handyman should have some knowledge of their construction. The floors of modern homes may be roughly grouped under two main headings. These are:

(a) Suspended floors.

(b) Solid floors.

Suspended floors are the boarded type found in the main rooms of the house. Solid floors are usually only laid down in kitchens and bathrooms, etc., except in the case of some modern homes which may have solid floors throughout.

Suspended floors consist of planks which are laid over and nailed to solid lengths of timber, the ends of which are supported by the main structure of the house. The sizes of the solid timbers, which are known as ‘joists’, may vary in size according to the type of house, the most general size being 4 in. by 2 in. In most cases it will be found that the joists are placed across the shortest width of the room and the planks are laid across the joists in the longest direction. The planks, or to give them their correct name, floorboards, may differ greatly in size and edge-shape between different types of houses.

Those in most common use are square-edged boards of 6 in. by 1 in. prepared softwood and these are secured to the joists with the floor brads described in the Fixings section – nails and screws. These are known as square-edge boards because the edges of the boards are flat and simply butt together as illustrated below. The edge joints of other types of boards less often used are also shown in the image below (A).

lifting floorboards and filling gaps

Solid floors usually consist of concrete, which may simply be finished with a smoothed surface or may be faced with tiles. Other surfaces for facing solid floors include plastic and linoleum floor tiles, but these are not usually laid down when the house is built.

Repair jobs to suspended floors may entail the lifting of a board. If the boards in a doorway become very worn or deeply scored the worn parts may be lifted and turned over to provide a new surface or new boards fitted. The handyman may also find it necessary to lift floorboards to obtain access to any of the main services, which in most cases are carried under floors.

Lifting Floorboards:

To lift a board it is necessary to find the nearest joist. This may be located by the position of the floor brads, which can be clearly seen. The exact outline of the joist may be determined by sliding a thin-bladed tool — a knife will do — in between the floor-boards until it meets the edge of the joists. When this is done, a pencil line should be marked across the board.

The floor-board is sawn through to remove a section of it and the saw cuts should be made near the joists. The boards are cut through with a keyhole saw (see ‘Nest of Small Saws’). If the edges of the boards are very close together it may be necessary to drill a small hole at the starting point to permit entry of the saw blade. The saw should be worked at an angle as illustrated in the image above (B). After one end of the board is sawn cleanly through, the board should be lifted by inserting a strong flat-bladed tool under the sawn edge and using the tool as a lever. The board should then be supported with a batten placed underneath it, as shown in the above image (C), and the second end of the board may then be cut through with a handsaw.


After the necessary under-floor repair has been carried out the floor-boards should be replaced as illustrated in the above image (D), which shows that the second end-cut is made across the centre of the supporting joist, and the first slanting edge-cut is supported by a short length of batten screwed to the top edge of the joist. It will be found advisable to use new floor brads when replacing the floor-board and the length of the floor brad should be twice the thickness of the floor-board, ie. for a 1-in. floor-boards the brad should be 2 in. long.

When nailing the boards home, set the nails at a slight angle towards the inside of the board. In the case of shaped-edged boards it will be necessary to cut down the length of the board before removing it from the joists; turned boards should be nailed in the middle as well as the sides to counteract heart-side contraction.

Filling Cracks between Floorboards:

Before redecorating a room or recovering a floor any cracks between floorboards should be filled in. This will cut down the entry of draught into a room and make it, more comfortable. Also it will give a longer life to the new floor covering. Additionally if the surface is to be stained or painted, the filling of cracks will ensure a neater and more workmanlike finish. If the gaps between the floor-boards are large, the best method of treatment is to use builders’ laths, which should be planed at one edge to make them wedge-shaped as illustrated above (E). The thin end of the wedge is then inserted in the crack and the lath hammered well and truly home. Any section of the lath protruding above the floor surface should be cut down with a hook-scraper or smoothing plane. Finish with a medium-grade of glass-paper.

Any empty knot holes or deep marks in the floor-boards may be filled with plastic wood which should be sanded level with the surrounding surface after it has hardened.

If the gaps between the floor-boards are uneven in width, or not large enough for the wedge-lath treatment, they may be easily filled with papier mache. This is made from scraps of newspaper which are torn into small pieces and placed in a saucepan. The paper is then covered with water and the mixture heated. When the paper softens, a small amount of decorators’ size-1 oz. of size to each pint of pulp — should be added to stiffen the mixture. Allow to boil for about five minutes then beat the mixture into a smooth pulp. The papier mache is pressed into the cracks with a putty knife or an old table knife and is finished just above the level of the surface. This should then be left overnight to harden and any rough edges cut smooth and level with diminishing grades of glass-paper, commencing with a fairly coarse grade.

Repairing Cracks in Solid Floors:

Repairs to solid floors usually consist of dealing with cracks or replacing tiles. To repair a crack in a concrete floor the crevice should be thoroughly raked out and the best tool for this job is the tang of a file. The edges of the crevice should be slightly undercut to provide a key for the repair material. After this the crevice should be thoroughly wetted with water applied with a brush. The repair material is a mortar made with one part Portland cement and one part sand, which should be mixed to a medium stiff paste with water.

Before applying the mortar, the crack should again be thoroughly wetted and the mortar mixture should be pressed well home with a trowel, smoothing it level with the surrounding surface. After the mortar commences to stiffen the cracks should be covered with layers of wet newspaper or cloth and the repair should not be walked on for three or four days after it has been carried out.

Repairs to tiled solid floors come under two main headings. Replacing loose tiles, and repairing cracked tiles. In the case of a loose tile, the tile should be removed with a thin-bladed tool and the cavity into which the tile fits should be slightly deepened and roughened by chopping the surface of the bed-concrete with a hammer and cold chisel. All particles of concrete and dust should be brushed from the cavity, which should be thoroughly wetted. The tile should be well soaked in water before replacing it. The replacement mortar can be a mixture of one part Portland cement to one part sand, mixed to a medium stiff paste, or one of the patent plaster fillers described previously may be used.

The roughened base of the cavity should be covered with the mortar and the wetted tile pressed firmly in place. If the tile sinks too low in the cavity it should be removed and a little extra mortar added to bring it up to the same level as the surrounding tiles. If the replacement tile stands too high above the surrounding surface it should be removed and a little of the mortar scraped out until the tile is level. The edge joints should be filled in with the mortar and wiped smooth with a damp cloth. After the repair the surface of the tile and the surrounding area should be cleaned with a damp cloth and the repair covered with several layers of wet newspaper or cloth and left for a few days without walking on it.

A cracked tile may be replaced in the same way. If parts of the tile are broken away and are lost a new tile of the same size and colour should be obtained from a local builders’ merchant. As an alternative, if a new replacement tile of the exact type cannot be obtained, the cavity may be filled in with a fine mixture of one part Portland cement to two parts fine sand, mixed with water, and the repair levelled with the surrounding surface with a trowel. When the cement starts to stiffen, the area should be thoroughly wetted and covered for several days with wet newspaper or a cloth. After the repair has hardened it may be suitably coloured.

Concrete and composition floors that raise damp should be treated with a bituminous compound. There are very good proprietary brands which give container instructions for use.

05. July 2011 by admin
Categories: Floors, Internal Repairs | Tags: , | Comments Off on Repairing Floors and Floorboards


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