Alongside the attention devoted to the components involved with door lining assemblies, running lengths of skirting throughout a building make up the majority of the second fix carpentry process, especially in terms of the time and labour required. The simplicity of the overall process makes it a very beginner friendly task - with many young apprentices practising their skills here. That being said, the correct and seamless installation of any moulding requires a fair amount of skill to achieve a perfect end result. There are a variety of a obstacles that may have to be overcome during the installation of skirting, though adherence to the basic principles can aid in doing so.

Preparing the workspace

As mentioned, the installation of skirting boards is a straightforward process, both in terms of required skill and intensity. This being said, the time and labour required for proper installation in residential properties is affected by access. Many building layouts make it difficult or impractical to set up our workstation near the fitting area, increasing the time required to carry out the task. Conflicts with the schedule can also impact the required time, with other trades that are on site often getting in the way. Both of these factors can be exacerbated by poor finishes to the plaster, uneven floors, as well as rooms that feature lots of small returns. Nonetheless, in order to carry out this task effectively and efficiently, we must take time at the beginning of the process to organise our workspace, as well as our mind.

To begin, we must first establish a workspace in which we can set up our tools. Ideally, this would be in a large room or space close to where all of the fitting is going to be taking place. In less ideal scenarios, this may be outside in the garden, or by the front door. In our workspace, we’ll need to set up our mitre saw on a stand or two, with enough room to easily manoeuvre the lengths of skirting. A bench or set of trestles should also be set up out of the way in order to create a work surface at a comfortable height to use our hand tools on the skirting. In terms of efficiency, the skirting board should also be stacked on the floor close to the work station.

With our tools set up, we can turn our attention to the areas of installation. Begin by moving from room to room and removing any waste materials or rubbish that is present in order to clear our working area. Ideally, the rooms will be completely empty, though this is not always the case. Anything that can’t be easily moved out of the room should be stacked together in the middle of the room.

In modern UK construction, the skirting boards are installed over a plastered finish, typical skimmed dry lining. When skimming the lower portion of the walls, a small gap is left to avoid dragging any debris from the floor into the plaster. This small gap is acceptable as the first few inches over the wall will be covered by the skirting, depending on the depth of the moulding. This abrupt start to the plaster can sometimes be a little bumpy, and often forms a small ridge/lip at the bottom of the wall. Sometimes the plasterers will address this edge, using their tools to flatten the belly and scrape off any excess material, leaving a nice finish for our skirting to sit flat against. In other scenarios, this messy finish is left to harden. As such, we must go around and scrape the walls before our installation begins. By using a large floor scraper, we can smooth out the bottom 3 or so inches of this messy edge in order to help the skirting sit flat against the wall. As a habit, it's good practice to perform this procedure regardless of the finish, as we can assess every part of every wall before installation whilst scraping. In doing so, we can look for any points of interest that could disrupt my installation, such as low pipes or sockets, bulges in the walls, etc.

With the walls scraped, the final step before cutting the skirting into place is to quickly sweep or hoover the area. In using a vacuum cleaner, we can remove any debris or dust along the edges of the walls that may interrupt our installation. If we scrape off a lot of plaster “snots” then we’ll have to remove these from the area too.

Approximate measuring and cutting

When installing skirting in multiple rooms or floors, many full lengths of skirting are used in the process. In order to reduce the waste created during the process, we begin to cut our lengths starting with the longest pieces first and working our way down in size. By cutting the full lengths of skirting to approximate lengths for all of the walls within the area that we’re working in before we begin to refine them, we can determine whether or not we have enough skirting to begin with. If we started in one room, cutting and fitting each piece sequentially we’d most likely be left with many odd sized offcuts. Also, if we need more skirting to complete the job, we’d only find out right at the end, as opposed to fairly early on in the process. Additionally, our overall efficiency would decrease. By making all the approximate cuts, and then all of the refinements, and then all of the fitting, we can maintain a good level of efficiency.

Where to begin?

As we move around the room cutting our pieces, it's traditional to start with the longest lengths first, and prioritise the lengths under the windows/behind radiators. In many instances due to the layout of rooms and the heat retention properties of radiators, these locations are typically one and the same. Alternatively, many operatives prefer a specific direction around the room to ensure that most of the internal scribes are preferable to their dominant hand. For a right handed individual, working clockwise around a room, will ensure that most of the scribes will be on the left hand side of the length. When cutting the scribe, the length can be flipped upside down, so that we’re cutting from the bottom up, on the right side of the length. The opposite is true for those that are left handed. This is the most comfortable position to cut scribes from when using hand tools.

Joining lengths

Where a full length is not long enough, or where access is tight, a join in the length may be required. Trying to fit long lengths behind radiators where access is tight may call for a join, but this can be easily hidden behind the pipes. Joins are created by splaying the ends of the lengths of skirting. The piece that will be fitted first is cut backwards at a 45 degree angle to a point. Once this is fitted, the other length is splayed in the other direction so that it overlays the splay on the other board.  When it comes time to fix these lengths, adhesive can be applied to the raw surfaces, and nails can be placed through the joints to prevent movement and cracking over time. The joint can be sanded after installation, and providing the alignment during installation was correct, the joint will disappear once decorated. Lengths are never butted together as joints, as the expansion and contraction of the timber will cause this joint to open up over time.

Coping internal corners

Traditionally, internal joints are never mitred to the irregular angles of internal corners, and are scribed instead. A scribe is a fast method of creating a tight internal corner. To scribe a length into another, begin by cutting an outwards splay at approximately 45 degrees on a length of skirting. Regardless of the profile of the skirting, we will be removing all of the raw waste left by the backwards splay, cutting on the waste side of the intersection between the flat face of the skirting and the waste. In order to create a tight joint, we will back bevel the cut as we follow the profile of the skirting. For most skirting mouldings, the bottom half of the skirting is flat, and we can begin our cope using a handsaw to back bevel along this line until we reach the moulding. Once we reach the moulding, regardless of the specific profile, we can use a coping saw to follow the definitive line, undercutting the angle ever so slightly. With the material removed, the cut should receive comfortably into the face of another length. If a gap is present, it is due to the angle of the two lengths meeting incorrectly. In most instances this is due to the other length not being installed plumb. If this length isn't fixed yet, we can pack it plumb so that it meets the scribe nicely. If it is fixed, we may have to adjust the angle of the flat back bevel to meet the face of the other length, or possibly remove some of the moulding scribe. This method can be used on irregular internal corners, such as around the inside of bay window projections, by back-beveling the scribe at an extreme angle so that the waste does not interfere with the joint coming together.

External mitres

External mitres occur where a run of skirting returns around an outside corner. Ideally this is at 90 degrees, hence the name mitre, though this the corners are rarely a perfect 90 degree angle. In its simplest form, the two lengths come together with 45 degree back cuts on them, so that the front edges meet at 90 degrees. Many instances can affect the lengths coming together to form a tight joint, such as an out of level floor or bumpy finish to the plaster of the lower wall. If the lengths rock on the wall, then this can affect them meeting nicely. Additionally, if we’re using machined timber as skirting, cups in the boards can affect the mitre coming together correctly. Where possible, we should keep the cuts at 45 degrees and assemble them away from the corner, fitting it to the corner after the fact. If this isn't possible, we may have to make adjustments to the cuts to get them to fit. When held tight against the wall, a gap may be present either at the top or bottom of the mitre. In this instance, we can recut the 45 degree angle with a 1-2 degree compound angle in the right direction to give the piece additional length in the mitre. In most instances, this is enough to close up the mitre. These external mitres are glued together and nailed through the face of the skirting, into the wall and into one another to prevent the joint from opening up over time. Once fixed in place, the sharp edge is gently brushed away with sandpaper to create a more refined aesthetic, additionally creating a seamless joint.

Curved skirting

Where skirting must be installed around a curved internal finish, numerous relief cuts can be made in the back of a length in order to allow it to bend around a curved wall. This being said, extreme curves must be made from engineered timber. The skirting can always be steam bent to better match a curved wall. Some manufacturers sell machined skirting with grooves in it in order to be bent or curved around a surface. This isn't tremendously common in modern construction, but examples can be seen in curved existing bay windows.

Scribing

Where skirting is installed upon a finished floor such as laminate, the lengths may need to be scribed into the floor to create a good fit. Downwards pressure on the skirting during installation is often enough to help the bottom edge to meet the floor, though in some instances dips or bumps in the floor may be present. To overcome this, simply lay the skirting in place, and use a pencil to trace the contour of the floor onto the bottom edge of the skirting. Use a handsaw or plane to cut to this contour, and the skirting should fit tighter to the floor. A second pass may sometimes be required to overcome a poor floor installation.

Fixing skirting boards

Once a good amount of pieces cut are cut, if not all the lengths for a room, we can move onto fixing them. In dry lined rooms, adhesive and second fix gun nails can be used. In rooms with plastered masonry, screws and plugs may be required. For the former, we can apply adhesive to the back of each length, and push it against the wall. Using a nail gun, we can move along the length starting at one end and fix it to the wall, putting downward pressure on the length as we go to keep it down and back to the floor and wall. Two fixings should be placed approximately every 400mm along the length, angling the nails in a cross pattern to prevent draw out whilst the adhesive sets. When fixing into masonry, we must use an SDS drill to drill holes to receive plugs and screws. In some cases we may encounter crumbly internal blocks in old houses that don't take plugs well. For best result here, we should drill an undersized hole and insert the plugs flush to the front of the skirting. Without hammering the fixings in, simply tighten the screw, and this usually is enough to pull the skirting back whilst the adhesive sets. Sometimes props can be used to wedge the skirting tight to the wall whilst the adhesive dries. Traditionally, adhesive wasn’t used, and simple cut nails were used to fix the skirting to the masonry walls. As a rule of thumb, fixings shouldnt be placed above or below sockets, switches, or pipes, so as to prevent potential damage to these components. As each length is fitted, ensure that internal copes are tight and external mitres come together well. When fitting external mitres, wood glue should be put on the mitre to prevent it from opening over time. Nails can be used to pull the mitre tight during installation before the adhesive sets. The edges can then be cleaned up with pieces of sandpaper.

Decorative grooves for low pipes

Where we encounter radiator pipes coming out of the wall lower than the level of the skirting, we may have to create a decorative groove to accommodate this. In principle this is easy, and requires only a few cuts. The specific angle we’re working with here is 22.5 degrees, a common setting on a mitre saw. First, we make our angled cuts on the long lengths that are coming up to the pipe, as shown in the diagram. Another angle in the opposite direction can be cut on a smaller length of skirting. This will receive into the first cut. A mark can be made in line with the underside of the pipe, with a small tolerance for clearance. Another cut can be made here. Finally, a small ripped down length can be cut on both ends to fit under the pipe. This method can be adapted for other mouldings or methods.

Built up skirting

Whilst not so common in modern construction, built up skirting is a traditional method of creating larger decorative skirting profiles. A diagram here shows how the skirting would have been assembled on the walls from multiple different profiled lengths of timber.