Last edited 16 Feb 2021

How to fit carpet

Carpet is a type of flooring made of an upper layer of pile attached to a backing. The pile is usually wool or fibers such as nylon, polyester or polypropylene that are heat-treated after having been twisted together into tufts or woven. There are many varieties of texture, style and colour available and generally carpet is both durable and easy to maintain. Carpet also has insulating properties in terms of both heat and sound. However, carpets can stain quite easily and can be damaged by water and damp.

For more information, see Types of carpet.

When fitting carpet, the first step is to measure the amount required. The room to be fitted should be drawn in a simple diagram and broken down into smaller rectangles to calculate the total area. For carpeting stairs, the area of each riser can be measured by multiplying the height and depth by the length. It is recommended that an amount be added for waste, usually 5-10%.

Before fitting a new carpet, the sub-floor must be prepared. It may be necessary, when pulling up old carpet, to replace damaged or worn floorboards. To level the boarded floor, as well as help reduce draughts from below, hardboard sheets measuring around 3 mm-thick should be used.

Once the sub-floor is prepared, carpet gripper can be installed. Carpet gripper is long, thin pieces of timber with small pins that are used to ‘grip’ the carpet in place and prevent them losing tension once laid. Carpet gripper usually comes in lengths of 1 m and can be cut to size if necessary. It should be used all the way around the edge of a room, except across doorways.

The underlay is an important element that adds cushioning underneath the carpet, influencing how the carpet will look, feel, and how durable it will prove to be. The underlay should be loose-laid, rubber side facing down. It can then be cut using a craft knife to make sure it is at the same level as the grippers. The edges should be butted together and joined with carpet tape, ensuring that they do not overlap, and that the underlay is smooth and level.

The carpet should be unrolled and stretched out onto the gripper using a carpet stretcher (or knee kicker) – a tool which grips the carpet in teeth at one end. After loosely laying the carpet in position and smoothening out (with around 50-75 mm excess on every edge), it can then be cut to size. Push down on the edge of the carpet so that it hooks onto the gripper. Work around the room wall-by-wall.

Where two carpet pieces are to join, they should be overlapped before using a knife to cut through both pieces to make sure the edges will match exactly. Then, a piece of adhesive tape should be centred on the floor beneath the join, and the seam sealed with a carpet roller.

Where the carpet has to fit around elements such as door frames or pipes, it should be cut to fit and then trimmed so as to leave it flush. To fit carpet across a doorway, it should be cut to be in line with the flooring in the next room. A door threshold bar should then be fitted to ensure the carpet edge is kept firmly in place.

To fit carpet on stairs, grippers should be used on each stair tread and underlay cut in strips. The underlay should be stapled to the stair tread and over the nose down to the next gripper. This should be done starting at the top and moving down. The cut should then be cut from the length of roll and fit from the top stair down, pushed into the grippered recess on each stair and ensuring that it is tightly puled over each nose before any excess being cut off.