Due to the frequent changes in elevation, it is harder to lay carpet stairs, than, say, your hallway. But do not let that put you off; if you have successfully rented other rooms, then why not the stairs?
Stairs can be carpeted with fitted carpet, on what's known as a runner – a strip of carpet.
Fitting runners to stairs
A woven carpet runner also enables the carpet to be moved occasionally to equalise wear. Old-fashioned stair rods with side clips might be used to hold a runner in place and form part of the stair decor, but it is now a lot more usual to use gripper strips. Unique pin-less grippers are offered for use with foam-backed carpets; the carpet is held in tight jaws. The wooden strips are utilized in pairs, one behind the tread, and one at the bottom of the riser, or you may get a metal version that's already formed into a right angle.
Cut the strips to length, this is crucial: 38mm shorter than the width of the carpet utilizing tin-snips or secateurs for wooden strips, or a hacksaw for the metal type. Nail them into place, omitting the bottom riser. The gap between each pair of wood strips should be just enough to squeeze the carpet down into. Cut the underlay to fit between the rods and tack close to the rods, omitting the bottom tread. No underlay is needed with foam-backed carpet.
Carpeting the bottom step
With a runner, an extra length of carpet is included so that it can be moved up to even out the wear taken on the treads: this is folded under the bottom step. The pile needs to run down the stairs to stop uneven shading and promote longer wear. Begin at the bottom of the stairs. Tack the end of the carpet face-down to the bottom tread, at the back close to the gripper. Lay it down over the tread to the bottom of the last riser, fold it back and tack the fold to the riser and tread. Run the carpet up the stairs, pulling it over the gripper rods and pushing it down between them with a bolster. It should join the landing carpet at the top of the last riser. If there is no carpet on the landing take the stair runner over the top of the final riser, turn under the edge and tack down.
Fitting carpet to the stairs
The fixings for a fitted stair carpet are as for a runner. The additional length of woven carpet is not needed at the bottom, though an underlay will need to be fitted to all of the steps. The gripper rods really should be the full width of the stairs. Fit the carpet from the top of the flight. The landing carpet will need to overlap on to the stairs and down to the bottom of the uppermost riser. The stair carpet should then be stretched over the gripper rods as usual and pushed down between them. Additionally, it will have to be trimmed to fit at the edges. No fixings are required at the edges.
Carpeting spiral stairs
Where the stairs go round a bend, gripper rods can not be used in the usual way. The carpet may be cut or folded to fit the turn.
Woven carpet: Fit the gripper rods just to the treads on winding stairs. Fold the spare carpet, with the fold falling down, and tack it to the bottom of the riser at 75mm intervals. Lay the carpet on top of next rod up and repeat the folding and tracking procedure.
Foam-backed carpet: Omit the pin-less rods altogether on spiral stairs. Tack the carpet to the tread, preferably at the back so that the tacks are not too obvious. Fold down the surplus and tack neatly on the underside of the riser.