Cladding interior walls with natural timber is an age-old decorative technique. Nowadays, it’s most popular in the form of narrow boards.
They look extremely attractive and have other advantages too. Panelling is a perfect cover-up for plaster in poor condition, and for lumpy walls often found in older houses. Moreover, it has excellent insulation properties.
If you plan to panel one or more of your walls, go and see what the timber merchant has to offer. Cedar, ramin, mahogany and meranti are all possible woods for the purpose. But by far the most popular is ‘knotty pine’ -softwood of various species with knots that would be unacceptable in ordinary joinery work. It’s available from almost all suppliers. The commonest size is 100 x 12mm , in lengths up to 3m . Width and thickness, as usual, are nominal: since the timber is planed smooth, these dimensions will actually be smaller.
Most boards used for panelling have a protruding tongue along one edge, and a groove in the other, so that each piece fits into the next. Quite often both outer edges are chamfered, forming attractive V-shaped grooves when the boards are interlocked; hence the name ‘TGV — tongued, grooved and V-jointed.
Boards with concave faces are also obtainable as in ‘shiplap’, which has one edge rebated to overlap the thin edge of the next board. It’s almost always used horizontally. Horizontal cladding creates the optical illusion that the wall is wider than it really is: vertical cladding makes it seem taller.
Battening the wall
All cladding is normally fitted onto 50 x 25mm rough sawn softwood battens, which are themselves nailed or screwed to the existing solid wall.
They’re unnecessary if the wall is a hollow partition , framed with vertical studs and horizontal noggins to which the cladding can be nailed. But be quite sure you’re nailing through into the timber frame and not just into its covering, which is usually plasterboard and thus won’t hold the nails well. If cladding the inside of an external wall, you can keep out damp with a vapour barrier such as polythene sheeting. You simply place it under the battens before you fix them to the wall. Even if you don’t include a vapour barrier, it’s wise to treat the battens and the back of the cladding with wood preservative, in case condensation leads to rot. And the job also offers a unique opportunity to fight heat loss, for you can easily place insulating material between the wall and the cladding.
Buying the timber
If the shop prefers to supply panelling in assorted lengths, it will be cheaper to buy it that way, rather than in the exact dimensions you want; but many suppliers now sell TGV in pre-cut bundles, containing timber in lengths of 1800mm , 2400mm or 3000mm .
To work out how many lengths of vertical cladding you need, divide the wall width by the board width – remembering that the board’s face will be only about 90mm wide if it’s nominally 100mm .
For horizontal cladding, divide the wall height by the board width. For board length, just measure the wall – though on wide walls you may have to fit boards end-to-end.
Before buying boards always check them -especially knotty pine – for splits, loose knots, discolouration and twisting. Don’t be afraid to reject bad ones.
Battens should run at right angles to cladding; in the case of diagonal panelling, either vertically or horizontally. They should be spaced about 600mm apart, except that the first and last in a row of vertical battens should be at either end of the wall. And you’ll always need battens next to doors, windows and other fitments, and under any butt joints between the ends of boards.
Buy your cladding at least two weeks before use, and keep it inside the house. This is because your home will be warmer than the place the timber has been stored. The heat will reduce the amount of moisture in the wood, which will make it shrink. You should therefore give this time to happen you fix the cladding in place; otherwise it will shrink afterwards. That may result in tongues coming out of grooves, which will leave unsightly gaps.
As soon as you get the cladding home, lay it flat on the floor in small piles, with boards face to face. Leave it for a fortnight, shuffling the boards around every few days. Don’t attempt to dry them out artificially, as this will be sure to warp them.
Whatever area of cladding you have been fixing, you will need to finish off the edges where the cladding meets other walls, ceilings, skirting boards and openings.
Finish off with quadrant, triangular or scotia moulding, pinned into the angle.
Where there is an existing coving, stop the cladding just below it and fill the gap with scotia moulding . Otherwise take the cladding up to ceiling level and finish with quadrant or other beading .
Where the cladding covers both walls, plane off the tongue for a neat overlap, and cover it if you wish with a decorative moulding . If only one wall is covered, finish off with a vertical strip of wood pinned to the ends of the horizontal battens .
Fixing the cladding
If the wall is solid, use masonry nails, or screws in plastic plugs, to fix the battens. Take care not to drive them into cables or pipes; be especially careful round electrical fittings. The important thing is to get the battens at a constant level, both vertically and horizontally. Insert pieces of hardboard, plywood or scrap timber behind them where necessary. On a slightly concave wall, for example, you’ll have to pack behind the centres of the battens to get them truly vertical, whereas on a convex wall you’ll have to pack behind the top and bottom of each batten.
Then position a piece of cladding as the first in the row – usually against a side wall . If the side wall isn’t vertical, or is uneven, you’ll have to scribe the board and cut to the resulting pencil line.
Place the first board so the tongue is ready to fit into the next piece, and nail the board to the battens. Another method, which avoids your having to conceal the nail heads, is to fix this first board with impact adhesive . This will hold it firmly in place straight away without nailing or cramping.
You can nail the next board through its tongue, angling the nails inwards. The heads will be covered by the groove in the following board. Use this ‘secret’ nailing for all the other boards too, except the last. With cladding other than tongue-and-groove, such as shiplap, there is no tongue; so secret nailing means placing the nails where the rebated edge of the next board will cover their heads.
Repeat the fitting and nailing process right across the wall, checking that each board is still vertical . When you get to the end, it’s unlikely that the last board will fit exactly, so you’ll probably have to scribe it.
Even once you’ve cut it to shape, you may have trouble squeezing it in if you’ve already nailed all the other boards in position. There are two ways of dealing with this. One is to fit the last three or four boards at the same time, inserting the tongues in the grooves and then springing them into place, before nailing through their faces. The other is to plane or chisel off the back of the groove in the last board, and simply lay the board onto the battens – fixing it either with impact adhesive, or nails.
An external corner means planing off the tongue, at least from the last board. If the cladding continues round the corner, give the angle a neat finish by butting the grooved edge of the next board at right angles against the tip of the last one, perhaps pinning a right angle or ‘birdsmouth’ moulding over the join. If the cladding ends there, your best bet is to nail a small rectangular-sectioned piece of planed timber to the ends, of the battens so that it covers the edge of the last board as well. This method will also work at a door frame.
At an internal corner, just butt the boards together, or butt the last one against the next wall if the cladding ends there.
A quadrant, triangle or scotia moulding will give added neatness; you can use this along the junction with the ceiling too, or below aceiling moulding.
Skirtings and other features
If the wall you’re panelling has an existing skirting board, it’s best left on and used as a batten, nailing the cladding to it. If it’s thinner than the other battens, you’ll need to pack it out first. So nail on a strip of timber, hardboard or thin ply-
wood, to bring it to the right thickness.
You can also use it as a recessed plinth. This will prevent the bottom of the cladding from being scuffed or damaged. Stop the cladding short of the floor, so that it ends some way up the skirting. Or fix the bottom of the cladding to a batten nailed immediately above the skirting. Leaving the whole of the skirting exposed.
Alternatively, you can put new skirling over the cladding. With horizontal cladding, back the skirting with short lengths of board, nailed one to each batten, rather than wasting a whole board behind the skirting. Another form of skirting is a quadrant moulding .
If the old skirting is thicker than the battens you’ll have to take it off carefully, or it will prevent you from nailing the cladding flat. If it’s an obsolete pattern, removing it has the advantage that you can still match the room’s other skirtings, because you can put it back on top of the cladding.
MORE FINISHING TOUCHES
Finishing off cladding neatly at a doorway, skirting boards and round electrical accessories can be tricky. Here are some solutions.
Fit cladding up to the door frame, then pin a vertical strip to the ends of the battens and add new door architrave moulding.
Pin battens round surface-mounted fittinqs and cut the cladding to fit flush with the edges of the mounting box . The face plate may not be exactly flush with the cladding surface.
Pin the cladding directly to the skirting at floor level or higher , or fix battens just above the skirting board .
Like skirting, the architrave round doors and windows can either be removed or left. If you remove it, finish the cladding with strips of wood, in the same way as for any external corner where panelling ends; for decoration fit architrave on top of the boards. If you leave the old architrave, fit battens up against it where necessary, nail the cladding to those, and cover its edge with a right-angle, birdsmouth or rebated moulding, planed to fit.
Electrical sockets also need battens next to them. A surface-mounted box generally needs no further treatment, since its face will end up more or less level with the surface of the cladding.
The simplest way of dealing with a flush-mounted box is to re-fix it to the wall surface, put battening and cladding next to it, and screw the face plate back on to overlap the cladding. Flush-mounted box is too deep or shallow for this, use it as if the cladding were plasterboard. That is, attach special metal lugs to the sides of the box, so that screwing on the face plate clamps the box to the cladding.
Wall-mounted light fittings can usually be dealt with by re-fixing them onto the cladding, having drilled a hole through it for the wires.
The cladding, of course, will need to be cut round all projecting features.
As you fix the cladding, punch any visible nail heads below the timber surface. Then, when you’ve finished, you can fill the holes with a matching-coloured wood filler. Next, sand the entire timber surface with fine grade abrasive paper. An orbital sander will take much of the hard work out of this job.
When you’ve prepared the surface in this way, you can apply a stain, if you want to give the wood a deeper, richer or brighter colour. Follow this with a clear varnish in a matt, satin or gloss finish according to your taste.
Natural timber panelling is like most things in carpentry: once you know how it’s done, you can vary the idea in all sorts of ways.
The basis of the technique is battens. They’re used for two good reasons. First, they take up any unevenness in the wall. Second, because they’ll be covered by the cladding, you can fix them firmly to the wa without worrying about how the screw or nail heads look. So, for any panelling scheme except on a stud-partition wall, you’ll need to plan for battens.
But, once the battens are in place, you have tremendous freedom with the cladding that goes on top. Staining or painting offers the most obvious possibilities – even the character of traditional knotty pine tongued-and-grooved boards can be altered greatly by a wood stain in, for example, reddish or dark brown.
But you needn’t stick to that particular timber. Although hardwoods are more expensive, you may think them worthwhile if the wall you’re panelling is small. Or you may choose to include a small area of an unusual timber, perhaps at an angle, as a feature in the middle of a more conventional wall. Ramin, for instance, contrasts with knotty pine in being absolutely straight-grained and free of knots. 1 A panelled loft
In converting this loft, tongued-and-grooved boarding makes a homely feature of a low wall and awkwardly sloping ceiling. It’s been stained and then finished in a clear matt lacquer.
Even more interesting are the parts that can’t be seen. The battens to which the wall cladding is fixed have been nailed to the short studs inserted between joists and rafters. The battens for the ceiling cladding have been nailed to the underside of the rafters.
The ‘reveals’ or sections of wall on either side of the dormer window consist of plasterboard, cut to shape and nailed to the window’s timber framework. The plasterboard reaches right to the TGV cladding, and so hides the ends of the battens as well as the faces of the rafters. 2 A feature wall
The cladding of this sitting-room wall shows more than one imaginative touch. To start with, the boards are 300mm wide, which makes an imposing effect. Even more unusually, however, they are not solid timber, but sheets of teak-veneered chipboard, cut up and re-arranged to give the random look of natural planks. This, of course, is very much cheaper than using solid teak!
The cladding is fixed directly to a timber-framed partition wall. The wall has been painted matt black, to offset the timber, so have the edges of the chipboard.
All the fixing is through the plasterboard surface of the wall and right into its vertical studs, so no battens are needed. For effect, great care has been taken to line the screw heads up.