Modern floorboards are straightforward components to install, provided that the correct layout of the underlying joist structure has been undertaken. That being said, simple workarounds exist to overcome less desirable starting conditions. The first step in installing subfloor sheathing is to effectively establish an area to stack all of the sheets for cutting. Somewhere out of the room but close to the area of operation is ideal, though if not, then the far side of the room parallel to where the first row will be installed is best. This ensures that by the time the flooring installation reaches the pile of flooring, the majority of the boards will be used up and so only a small number of will have to be moved. In order to avoid confusion during the cutting of the sheets, all of the boards should be stacked in a pile in the same orientation that the boards will be installed in the room.  

To install the boards, the first two rows must be established and fit together “dry”. This entails cutting the boards to length, and locking them together hand-tight without adhesive, so that they display the correct total size, but can still be pulled apart again for the adhesive to be added. Doing so ensures that both rows are ready for installation in one go, once the fast-setting adhesive is applied. With two rows installed simultaneously together, when all of the joints come tight and the boards are spaced correctly off of the wall, we know that remaining rows will be correct. Adversely, if we started with only 1 row glued and fixed to the joists, we might find that the second row does not seat fully due to any discrepancies in the assembly of the first row.

The first step to preparing these two rows is to take a general survey of the room and formulate a plan of action. Decisions need to be made about which direction within the room the flooring will be laid, and which end of the room we will start from. If the floor joists have been installed correctly with a 400mm OC layout then we should start from the end of the room at which this layout begins. Ideally the joints between the boards should land directly above a joist, though there are steps that can be taken to ensure appropriate stability to the boards if this is not the case. In some scenarios the first board of the row may need to be cut down in order to allow for the rest of the row to fall correctly on the 400mm spaced joists. Additionally, the first row of boards may need to be ripped down lengthways depending on the length of the room.

In our example here, the room is 3.75m long. Every full row that is placed down is 600mm in width, and so we can perform a simple calculation to work out the total number of rows required. For this example, we’ll divide the total length of the room by 0.6m which returns a value of 6.25. This means the total length of the room will be covered by 6.25 rows of flooring. 0.25 / 1/4 of a row/board is a 150mm rip, which is thinner than we want to install at the end of the system. Ideally, we’re looking for the last row to be at least 300mm wide if it needs to be ripped down, as boards that are 300mm or less in width are not as stable as full width boards. Tolerances exist here, and there is no hard and fast rule, but generally speaking we don't want a very thin rip to fill in the last row.

In order to increase the width of the last rip then in this scenario, we need to reduce the width of the first row. As it stands, if we are to install the flooring with a whole row at the start, the last rip will be 150mm. We want to increase this rip to half a boards width by adding 150mm, therefore we need to rip 150mm off of the first row.

With this calculation performed, we can begin to cut the first row. Measurements on these boards should be marked out with the tape hooked on the shoulder of the joints, and not from the end of the tongue, as this tongue is not included in the total finished width or length of the boards. Pay attention when marking out these boards to cut them in order to ensure that we’re cutting the correct part of the board off. For other sheet materials, specific orientation doesn't necessarily matter, though with these tongue and groove sheets the orientation is very important. The actual direction of installation isn't particularly important, whether we’re installing the sheets with tongue facing forward or the groove facing forward. Regardless, when cutting these sheets in any direction we want to pull our measurement from the edge that we want to remain on the sheet. The very first board should be cut to length in order to fall half on a joist.

In renovation and remodelling scenarios, if the end of the full sheet lands very close to a joist we can install timber on the side of the joist in order to pick up the joint. Alternatively, flat solid blocking can be installed between the joists in order to support any joins in the sheets, though this really is a last resort. There is a potential that this first sheet may need to be cut to length to fall onto a joist, allowing for the rest of the row to be whole boards. The boards within a row should not be cut to length, as this will remove either the tongue or groove from the component, disrupting the system. With the first sheet cut, and laid in place approximately, dry fit more whole sheets to complete the first row, cutting the last sheet to length for it to fit. Keep in mind that during the final installation we need to maintain a full 10mm expansion gap around the perimeter of the flooring system away from the wall, and this allowance needs to be factored into the cutting of these sheets.

An important safety tip is to spread some whole sheets around within the room, fully supported at each end to allow for easy passage through the unfloored room. As the rows are installed the room becomes safer to walk inside of. Make sure as well that during the dry fitting stage, the ends of the boards fall properly on the joists to avoid injuries from occurring.

The rips from the first row being cut down to width can be discarded away from the area of operation to avoid confusion. The offcut of the first row should be kept and cut down to length in order to start the next row. Ideally, we want this piece to span across 3 joists for appropriate support and strength within this piece. In our scenario here, we have approximately half a sheet offcut, that we can use to start the next row. With this piece in place, we can lay more sheets in place to complete the second row. The sheets have a staggered brick bond appearance, which is perfectly for stability. In all scenarios we want to avoid any joints within the rows from lining up with each other. For rooms that provide a small offcut from the first row, we can cut a new board down to an appropriate length to start the next row, whilst simultaneously staggering the joints in the rows.

With the first two rows cut and dry fit together, we’re ready to start installing the components. Mark the top of the joists along the edge of the second row. Expanding flooring adhesive sets very quickly, and to avoid any unnecessary glue scraping, we want to keep our adhesive within this line, and not onto the joists of the third row of flooring. Pull the two rows of flooring away, moving the first row of flooring to the location of the second, revealing the tops of the joists under the final location of the first row.

Working rapidly, apply adhesive to the joist just short of the line we marked before, and pull the second row of flooring into place, making sure to glue the front tongues of the first row. Use 10mm spacers sat on top of the joists to space the first row of flooring away from the wall the appropriate distance. Use a block of wood that spans over a few joists and a hammer/sledgehammer to tap the two rows together, making sure all of the joints are tight between each board. Use 10mm spacers at one end of the rows to space the boards off at the appropriate distance, and use a crowbar at the other end to wedge all of the joints together. At this point, the two rows should be located correctly in place and all the joints should be tight.

Use a nail gun with 60mm ring shank nails to nail through the face of the flooring and into the joists below. The gap between the flooring and the wall should clearly display the location of the joists, and a visual line should be drawn from these points to the exposed ends of the joists, with nails being inserted along this line. There should be 4 nails per joist across each board, with the nails towards the edges of the boards being kept in slightly to avoid damage to the tongue and grooves. The very last nail at the edge of the last row should be left out until the next row is fitted and ready to be fixed, in order to prevent binding in the T+G system during installation. 

From here, the most stressful part of the experience is over, with two full rows fully fixed up, providing a decent foundation for the rest of the flooring to be installed from. Each row can now be cut and installed as required. The offcut of the previous row should start the next row where possible, maintaining a staggered layout across the whole flooring system. Lines can be drawn in order to help maintain straight lines of nails above the joists if required. Sometimes, dubious locations where pipes or cables are close to the surface may need extra care to be taken in order to mark them out and avoid fixings in these areas. If our setting out was correct, the last row can be ripped down to the correct width and installed with ease, finishing the room. Sometimes in bathrooms, “traps” can be intentionally cut and left unfixed within the system to allow other trades access to the underside of the system.

This principle can also be used to create temporary access traps in the system to allow for the passage of materials and people between floors in scenarios where access is otherwise limited. To create these traps, dry fit an entire row within the flooring system. Decide upon the location of the trap, and mark this on the relevant sheet of flooring, making the marks halfway on the two joists either side of the trap. Cut this section of the board out, use a circular saw set to depth in order to remove the back side of grooves on this small piece. This allows for this piece to be removed at will, without being locked into the tongue and groove system. Care should be taken to ensure that adhesive is not applied to the underside of the trap, else it will be stuck down unintentionally.

Another scenario includes taking the flooring through doorways and into other rooms. For these situations, the rows of flooring should be installed in one room, up to the doorways, and taken through it where required. From here, the flooring in other areas of the buildings can be installed backwards from this point and cut to fit in these scenarios. Care should be taken to always avoid joints between boards within a doorway, as these high traffic areas always lead to squeaking.

The process for cutting and installing traditional sawn flooring, both regular and tongue and groove, is essentially identical in practice to the installation of modern floorboards, with a few minor differences. These include -

●       Adhesive is not traditionally applied to these boards, with flooring cut nails having been used in the past to fix them. This is typically the primary source of squeaky floorboards within a house though.

●       Purpose designed floor cramps are used to tighten the rows of flooring prior to fixing. This is necessary due to the natural defects present within this raw timber product, in addition to the increased numbers of rows within the system.