How To Fasten Wood to walls, floors and ceilings

Before you can make anything ‘built-in’ you must be able to attach wood to walls, floors or ceilings. This is a basic skill, required for nearly all features. But since the methods are always similar we thought-it best to cover them all in one, separate place. Also, the method you choose at any time will not depend on the object you are making, but on the nature of the wall or floor to which you are attaching it. Obviously, you will need a different method to attach a kitchen cupboard to a wooden floor than you would to a concrete floor.

Attachments to walls

First you must discover just what the wall is made of. The main types are:

Timber

This is unusual nowadays, but some older houses have partition walls made of boarding. This is naturally the easiest type as you can screw directly into it.

You can detect timber walls by a simple scratching test below the wall covering. Lath and plaster For division walls that carry no load, this is one of the most common types. The structure is a wooden frame, to which laths (strips of thin wood) are nailed. This wooden structure is then covered in half an inch or so of plaster.

You can detect lathed plaster by its hollow sound when tapped with the knuckles, the thinness of the walls as seen at door openings, or by boring a thin hole through the plaster. The drill will pass through the plaster, then through the thin wooden laths, and then out into the hollow centre of the wall. (Of course this hole is drilled between the wooden parts of the framing, easily found by tapping the wall.)

Framed plasterboard

This is very like lath and plaster, but the plaster is applied directly to the wooden framing, without laths, as large sheets. This is the modern method. A drilled test hole, between the framing, will show plaster but no backing laths.

Breeze or light concrete blocks

Interior walls in modern houses, and a few outer walls, may be made of a lightweight cast block, often with a hollow interior. The surface is made smooth with plaster. Most of these blocks are soft and may be fragile to hammer blows.

You can detect these materials by tapping—the wall feels ‘solid’, and by a test drilling which will soon pass through the thin plaster and into the soft breeze or concrete behind. If you strike a harder interior, it may mean that your drill has passed into the cement between the joints, which may be much harder than the blocks themselves. Try again an inch lower and to the side. Brick, stone or hard concrete The most common of outer wall materials, these are made by cementing the blocks together, with or without a final skinning with plaster.

You can detect these sort of walls by their sheer solidity, (they are often a foot or more thick) and by a test drilling through any surface finish. The drill will slow down a great deal against the resistance of the blocks or bricks. Red powder from the drill will confirm brickwork. Grey cement dust usually means concrete blocks. Grey-brown may mean stone of some sort. Of course, this is assuming that you have not driven the drill into the mortar between the blocks, which would bring up a cement dust in all these cases. Make one or two tests to be certain.

Other materials Though much rarer, one sometimes meets unusual walls; hardboard on wood framing, slate, flint, or some forms of precast, prefabricated panels in ultra modern houses. Usually a little investigation will easily enable you to choose a suitable attachments method.

Once you have found out what sort of wall you are dealing with, you can select your attachment method.

Simplest of all are NAILS.

You can use nails to attach wooden parts to walls made of wood. Also to attach parts to lath and plaster or framed plasterboard, by tracing the underlying wooden frame and driving the nails into this, clean through the plaster. But you cannot attach anything by nails to the lath and plaster itself. The nails must go through into the wooden framing inside the wall.

Again, you can use nails in any wall made up of cemented blocks, provided you can drive the nails between the blocks, in the cement used there. Unfortunately this is not usually a simple matter, since these joints are hidden beneath plaster. Also, the cement may well be very hard, causing ordinary nails to collapse uselessly. This is one method where the masonry pin may be well used. If you can find the joints, and drive masonry pins into the cement, a reasonably good attachment may be made.

Plugs

You cannot use nails, as a rule, for direct attachments to breeze block walls, bricks and blocks of all kinds, other than by the above method. If you cannot find the joints, you must try another way. The simplest direct attachments to such solid walls are PLUGS.

In essence, plugs are simply tubes of fibre or plastic, pushed into holes drilled in the wall. Then the attachment screw is driven into the tube, which expands to grip the hole tightly. But you can also make larger plugs in wood, drive them into holes in the wall, and then drive screws into them.

Taking tube-type plugs first, you will have to drill into the wall, which at best is done with a masonry twist drill held in a small power drill. Set the speed as slow as possible and drive the bit slowly but firmly. You must get right down below any plaster into the solid wall behind, because expansion tubes will burst plaster apart. Get at least an inch into the brick or stone behind. Then clear away the dust, by blowing across the top of the hole. This will suck out the dust, but close your eyes while blowing. Then slide in a plug-tube of the right length to end up dead flush with the plaster surface. It will matter very little if it goes in a fraction too far, but any projection from the surface must be cut away. With fibre tubes, it is as well to twist the screw tip into the plug end before pushing it home.

The screw gives you something to push with and its tip cuts a ‘starting thread’ inside the tube which will make it easier to drive finally.

If a twist drill is not available, there are percussion drills that are very cheap, but it is harder to make clean, accurate holes. They are simply tapped into the solid wall with a hammer, removing them from time to time to get rid of accumulating dust.

For really large objects requiring great strength one may use expanding plugs in steel, that are similarly inserted into pre-drilled holes. Alternatively you may plug the wall with timber in one or two places.

This plugging is done by chiselling into the plaster, if any, to expose the joint of the blocks behind. Then, the cement in the joint is dug away till a deep hole is made.

A shaped wedge of wood is then hammered down into the hole, its end being sawn off flush with the wall surface. Ordinary woodscrews are finally driven into the wooden plug to hold the fitment in place. Properly done, this is a very strong method and not so difficult as it sounds. It pays to lay in a small stock of filler cement to make good the plaster surface near the plug.

For attachments to laths and plaster or plasterboard, where you cannot screw or nail through into the wood framing, there are special types of fitting. These consist, in one form or another, of screw devices that can be passed through a hole drilled in the plaster, and which then can be expanded inside the hollow wall, so that they cannot return through the hole. A screw is tightened to give permanent grip.

All these devices work quite well, and are simple to apply. It is easy to drill through plaster. But it must always be remembered that the attachment is only as strong as the plaster and its laths, if any. It is useless to attach items of great weight, or imposing much strain, to a hollow plaster wall in this way. But as an addition to fastenings made to the actual wall frame, these sort of screw devices are very useful.

Attachments to floors

The methods used to attach things to floors are the same as those for walls. Obviously there is no problem with wooden floors in which ordinary nails or screws can be used. Other floor types are: Solid concrete Concrete is usually found only at ground level, but is sometimes used upstairs in newer houses. You cannot nail to it, but the tube type plugs are perfectly suitable, as described above for block and brick walls.

Terrazzo or quarry tile

Here again, the tube plug is useable, the only problem being making the hole. Really, a power drill is essential or the labour may be considerable. Incidentally, the fitting of these tiles is usually very close, so don’t be tempted to drive in nails or masonry pins at the joints. It is all too easy to crack a tile in half. Brick or stone slabs In older houses, these materials are still found. Either may be drilled for tube plugs or the joints are often wide enough to accept pins or nails, or to have wooden plugs inserted. But it is a good idea to get such floors resurfaced before building expensive, permanent fitments on them. The resurfacing will probably raise the level and cause all manner of future problems.

Parquet blocks

Though these are wooden, and therefore accept screws, in practice the thin hardwood blocks may be split or become disturbed if this is done. Also, they may be laid over concrete and the driving in of screws may lift them bodily. So it is probably best to treat these as solid floors using drilled holes and tube plugs. Also this does less permanent injury and any fitments can be removed leaving only a few neat round holes to be filled.

1 Strips of wood may be fastened to solid walls by using first-class quality MASONRY PINS which are of hardened steel. Do not buy the cheaper sorts, which shatter or bend badly. After attaching a strip to a wall with such pins, do not nail further items to it, or the pins may be loosened. Instead, use screws for all subsequent fixing to the original, nailed-on strip.

2 Tube-plugs are the most versatile of all wall and solid floor fixings. Holes are best bored by a twist drill specially made for masonry drilling, in a small power tool, but a small number of holes may be made

CAUTION Many modern, or recently re-laid floors of concrete may have a sheet of plastic inserted an inch or two below the surface to act as a damp-proof course.

It is essential that this sheet be not punctured by any drills or screws, or damp may rise at that point. There is normally a depth of at least 11-2 ins, of concrete above this sheet, but before inserting longer plugs it would be best to consult the builder if possible. Adequate strength can usually be obtained by using a larger number of shallower plugs. Indeed, with many structures you may even dispense with floor fastening altogether, relying on the structure’s weight and its wall fixings to hold it steady.

Cheaply by a PERCUSSION DRILL which is simply hammered into the wall, turning occasionally and removing to dispose of chips. Be sure that the drill passes right through into the brick or stone under the plaster, as plaster alone will not hold plugs securely.

3 Plugs may be of fibre or plastic, and some sorts are supplied in lengths to be scissored off as required.

4 Where really heavy fitments are to be attached, you may use EXPANDING SCREW PLUGS like this, slipped into the hole…

5 . . . and then the screw is removed, passed through the piece to be attached, and screwed home. The action of tightening the screw expands the plug to give a rock-fast fixing. Very good for concrete floors.

6 The older-fashioned but very effective method of fixing to brick walls is to use a thin masons chisel to dig out the cement between a joint to a depth of some inches…

7 . . . and then to slide a preshaped wedge of wood into the hole.

8 The wedge is hammered home, using an interposed strip of waste wood to prevent the wedge splitting.

9 Finally any excess is sawn away flush with the wall face. Normal woodscrews may now be driven into the wooden wedge. Such fittings will last indefinitely and will bear great weights.

Attachments to ceilings

Built-in furniture should never be designed to impose great loads on the ceiling. It is all too easy to bring down the plaster which, especially in older houses, may no longer be firmly held to its backing. In principle, one may use any of the methods described already, the soundest being to drive screws clean through the plaster into the wooden joists (framing) above. It is easy to find these wood joists by tapping, or often by

viewing the ceiling in a good light when the line of the joists may be quite visible. Do not be tempted to use nails, or you may loosen the plaster, and always bore a small hole through the plaster before starting the screw.

Where an attachment must be made to the plaster between the joists, use an expanding device, but do not do this unnecessarily.

In any case, such a fixing can support only the smallest load.

10 For thin walls, whether of applied boards or lath and plaster, various patent devices are seen. This sort is spring-loaded. The swing-back arms are thrust through the hole drilled in the wall face…

11 . . . and as soon as they are through, they fly apart. The screw may now be tightened and the spread arms cannot be

withdrawn. They should be fitted to bridge across any laths, in a lath and plaster wall.

12 Similar in pattern is this gravity controlled fixing. Push it through the hole…

13 . . . and once inside the longer end will fall, so that the device cannot be withdrawn.

The walls behind

Since the wall usually forms the back of a built-in fitment, should it receive any special treatment? In general, if it is not actually damp,

no unusual treatment is necessary. The surface should be smooth and even enough to accept paint or perhaps wallpaper.

But damp is a major problem, and must be dealt with. A wall that is slightly damp may be acceptable, but if that wall is inside a cupboard, the effect on anything kept inside that cupboard may be disastrous.

Dealing with damp is a complicated problem.

Hardboard may be applied directly to the rough but otherwise sound face of a lath and plaster wall, to give a perfect working surface. In many cases a better plan is to fasten a framework of two inch wide timbers in a lattice to the wall, then apply the board to this.

The other possible problem, either alone or in combination with dampness, is that of the wall surface itself being rough or irregular. This may be cured by replasteringnot an easy amateur job—but in many cases we have used a method that combines virtues of simplicity and cheapness. This is to cover the wall with sheets of hardboard, which is the cheapest of all the sheet materials and if fastened securely gives a wall that is smooth and clean. The easiest method is to nail directly through the sheet to the wall behind, but this is difficult except on wooden or lath and plaster framing.

For solid walls you must erect a rough framework of 2 in.xl in. rough sawn wood, like a lattice over the surface, and then nail the sheets of hardboard to this.

These notes are only intended as a guide where roughness and dampness are problems. In most cases, the wall behind fitments will require only minor treatment and any defects on it are concealed inside.

Leave a reply

Share On Facebook
Share On Twitter
Share On Google Plus