How to Lay Solid Wood Flooring

Solid wood flooring is a brilliant choice for your home. It has the power to completely transform the look and feel of a room. It’s durable, built to last, and gives you a timeless finish. Plus, because the wood is entirely natural, it matures beautifully over time. You’ll notice subtle changes in shade that only improve the character of your floor as the years go by.

Laying solid wood flooring isn’t overly complicated. But thorough and careful preparation is vital if you want to avoid future problems. We’ve put together a comprehensive how-to video alongside this written guide. We recommend watching the video first to see the techniques in action. Then, you can follow these practical steps to get the job done right.

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Solid wood flooring must acclimatise in the room for at least seven days before installation, and you must leave a 10-12mm expansion gap around the edges to allow for natural movement.
You can lay solid wood flooring directly onto a concrete sub-floor using flooring adhesive and a damp-proof membrane, provided the moisture content is 3% or less.
When fitting over existing floorboards or timber joists, you should secure the new floorboards at a 90-degree angle using secret nails for maximum stability.

How much solid wood flooring will I need?

Before you buy your materials, you need to know exactly how much flooring to order. Grab your tape measure and work out the size of your room in square metres. Simply multiply the length of the room by the width.

Once you have your total square metre figure, check it against the coverage listed on the flooring packs. We strongly advise adding an extra 10% to 15% to your total order. This extra amount accounts for cutting, shaping around obstacles, and general wastage. It’s always better to have a few spare boards than to run out halfway through the job.

Preparation and acclimatisation

Solid wood is a natural product that responds to its environment. It expands and contracts depending on the temperature and humidity of the room. This means your solid wood flooring needs to acclimatise to the room it’s going to be laid in.

You need to leave the unopened packs of flooring lying flat in the room for at least seven days before you start fitting. Don’t stack the packs more than three high. And try to wedge something small between each pack so the air can circulate fully around them.

Never store the packs by leaning them upright against a wall. This can lead to the boards bowing and warping, making them very difficult to fit.

Checking your sub-floor

Solid wood flooring tends to move a little more than laminate or engineered wood. Because of this, it needs a highly stable fixing. You usually fix it directly to a sub-floor rather than laying it as a 'floated' floor, and it's crucial to determine if your sub-floor is suitable before you begin, especially when it comes to moisture levels.

Concrete is highly porous, so you’ll need to check its moisture levels. As a quick guide, you can use duct tape to securely stick a one-metre square sheet of polythene onto the concrete and leave it overnight. If the concrete is damp, water droplets will collect on the underside of the plastic.

For a proper reading, use a professional moisture meter. Concrete sub-floors should show a moisture content of 12% or less on a prong test, or 3% or less on a digital moisture meter. If your concrete is too damp, you need to investigate the cause and fix it before laying any timber.

If the concrete is dry and suitable, apply a damp-proof membrane to stop future moisture. A good surface primer will then help your flooring adhesive form a strong bond.

It’s perfectly fine to lay new solid wood flooring directly onto your existing floorboards, provided they’re clean, completely dry, and level. If your current floorboards aren’t level, you will need to lay down a half-inch plywood sub-floor first to create a flat surface.

Setting out your room

If you’re laying your floor onto concrete or a fresh plywood sub-floor, the direction you lay your boards is entirely up to you. Laying them pointing towards a natural light source makes the joints less visible. Laying them horizontally or vertically will change the perspective and feel of the room.

It’s a smart idea to 'set out' your floorboards before you use any adhesive. This means placing a few loose boards across the room to see how they’ll be arranged. It helps you work out how wide your final row of boards will be.

To work out your rows, measure the width of the room and divide this by the width of a single flooring panel. Remember to include your 10-12mm expansion gaps in this calculation. If the width of your final row turns out to be less than 60mm, you'll need to trim your very first board lengthways. The goal is to avoid having a final edge board that’s too thin and fragile.

Setting out also helps you position boards that will sit next to radiator pipes. Ideally, pipes should sit in the middle of a board's width, rather than right on the joining edge. This makes cutting the wood much easier later on.

The importance of expansion gaps

Solid wood flooring requires an expansion gap of 10-12mm all the way around the edges of the room. This includes gaps around doorways and pipes. This gap gives the wood the space it needs to expand and contract naturally as the seasons change.

Failing to leave a proper expansion gap can cause your beautiful new floorboards to warp, buckle, and sustain permanent damage in the future.

We use flooring spacers to maintain this gap during fitting.

How to lay solid wood floorboards: step-by-step

Most solid wood flooring uses a tongue-and-groove fitting system. This guide covers how to fit a tongue-and groove floor directly onto a concrete sub-floor using adhesive.

Before you start sticking anything down, check that your room door will comfortably clear the new flooring height. You might need to trim the bottom of the door to make room. If so, remove the door from its hinges and set it aside.

Line up a small offcut of your new floorboard against the door architrave. Use your panel saw to gently trim the bottom of the architrave so that the new floorboard will eventually slide neatly underneath it. Use a hammer and chisel to carefully chip away the excess wood.

Start in the left-hand corner of your longest wall. Take your toothed trowel and spread your flooring adhesive from the edge of the wall outwards. Only spread enough adhesive to cover the width of two floorboards. Don’t spread more adhesive than you can comfortably cover in 30 minutes. If you leave it too long, the adhesive will start to dry out and lose its grip.

Lay your first board down with the groove side facing the wall. Press down firmly on the wood to ensure the board and the concrete sub-floor form a strong, tight bond.

Place your 10-12mm flooring spacers between the wall and the board. This creates your vital expansion gap. Put a couple of spacers along the length of the board, and one spacer across the width at the end.

Once you’re happy your first board is secure and perfectly straight, prepare your next board. Hold it from a slightly raised angle, connect the tongue and groove at the short end, and lower it gently into the adhesive. Alignment needs to be precise here, as you need your first row to be perfectly straight. Add more flooring spacers along the wall as you go.

Repeat this process until you reach the end of the row and can’t fit another full-length board. You’ll need to cut the last board to fit the remaining space.

Measure the exact distance between the end of the last full board and the wall spacer. Mark this cutting line on the underside of your new board. Make absolutely sure you cut from the correct end so the tongue-and-groove sequence still matches up.

Clamp the board firmly to your workbench. Use a jigsaw or a panel saw to make a clean cut. Slot the cut board into position to finish your first row.

If the leftover offcut from your first row is at least 300mm long, use it to start your second row. Start from the exact same end of the room where you began the first row. You should never start a second row with a full-length board.

The best way to lay solid wood flooring is to make sure the joints between the boards are staggered randomly across all the rows. This staggered pattern looks great and gives the whole floor better structural stability.

Remember to use a flooring spacer at the start of every new row. Keep checking that each board fits tightly against its neighbour.

You can use a tapping block and a crowbar to gently nudge stubborn boards into position. Never hit the floorboards directly with a hammer or a mallet, as this will easily crush the wood and break the tongue.

Once your first two rows are totally secure and straight, spread your next batch of adhesive across another two board widths. Repeat the laying and cutting process.

If you’re fitting flooring in a particularly large room, you can use tensioner straps after every five or six rows. These straps pull the boards tightly together while the adhesive sets.

When you reach the opposite wall, you will likely need to cut your final boards lengthways to fit the remaining gap, which you will have planned for during the setting out phase. Measure the gap between your last full row and the wall spacer. Cut the board to size lengthways and press it firmly into the adhesive.

Once the entire floor is laid, you need to wait for at least two hours before walking on it, allowing the adhesive to cure.

Laying solid wood flooring on joists and floorboards

If you’re laying solid wood flooring on joists or existing timber floorboards, the method changes slightly. You won't use adhesive. Instead, nailing with secret nails is your best option.

When fixing to existing floorboards, you must nail the new solid wood boards at a 90-degree angle to the original boards. Running them in the opposite direction gives you the most stable fit and stops the floor from bowing.

Drive the secret nails through the tongue of the new board at a 45-degree angle so the nail head is hidden when the next board slots into place.

Fitting flooring around a door frame

Fitting around doorways requires a bit of patience and careful measuring. Make sure you have already cut away a section of the architrave.

Measure the shape and size of the board you need to cut. Focus on the door gap between the architrave edges. It’s often much easier to fill a doorway gap using two smaller pieces of flooring rather than trying to cut one complicated shape.

We suggest using two boards to fit the gap. Mark your measurements and cut both boards to the correct length and width using a jigsaw.

Lay your cut boards flat against the architrave. Mark exactly where you need to trim the ends so the boards will slide neatly underneath the wood you chipped away earlier. Cut these final shapes with your jigsaw.

Slide your first section into place and push it under the architrave as far as it will comfortably go. Then, place your second board into position and connect the joints. Slide the first section back a little bit to ensure you still have your crucial expansion gap at both ends.

If you’re fitting a threshold bar between two rooms, choose one that matches your flooring style. Measure the width of the door frame, remembering to leave a 10-12mm expansion gap on both sides of the wood. Cut the threshold bar to size. Secure it to the sub-floor using grab adhesive or screws, depending on the manufacturer's specific instructions.

Fitting flooring around radiator pipes

Radiator pipes look tricky, but they’re easy to navigate with the right technique.

Lay your floorboard next to the pipe. Draw a straight pencil line on the board to show where the exact centre of the pipe sits. Next, lay the same board front-on to the pipe. Draw another mark from the centre of the pipe so it intersects with your first line. This cross marks exactly where you need to drill.

Clamp the board securely to your workbench. Use a 32mm flat wood drill bit to drill a clean hole through the cross. Radiator pipes are usually 15mm wide, so a 32mm hole leaves plenty of room for the pipe and the required expansion gap.

Draw a pair of straight lines from the outer edges of your newly drilled hole directly to the back edge of the board. Each line should run at a slight outward angle, creating a wedge shape.

Use a jigsaw to neatly cut along these two lines. Remove the small wedge of wood but keep it safe as you will need it in a moment. Fit the main floorboard into position around the radiator pipe.

Apply a little grab adhesive to the edges of the small wedge you cut out and slide it back into place behind the pipe. Finally, add a decorative pipe collar around the base of the pipe for a neat, professional finish.

Fitting floor skirting and trim

The final step is to cover up your expansion gaps. If you removed your original skirting boards before laying the floor, you can simply refit them now. The skirting will sit over the new floor and hide the expansion gaps perfectly.

Alternatively, you can use a decorative floor trim. This is the best method if you left your existing skirting boards on the wall. First, remove all the plastic flooring spacers from around the edges of the room. Measure the lengths of the walls to see how much flooring trim you will need.

Use a mitre box and a panel saw to make accurate 45-degree angle cuts at the ends of the trim. This ensures the pieces join together neatly in the corners of the room.

Fix the flooring trim in place using a strong grab adhesive. This is very important: do not fix the trim or the skirting directly to the solid wood flooring. Fixing it to the floor prevents the natural expansion of the boards. You need to apply the adhesive so it only grips the wall or the skirting board.

If you need extra security, hold the trim in place using small panel pins hammered gently into the skirting.

Now that you've finished laying solid wood flooring, you can step back and admire a job well done. We know tackling a home improvement project takes a bit of effort, but your careful preparation will definitely pay off.

Whether you've been laying solid wood flooring on concrete or fitting it over existing floorboards, if you follow these steps, your floor will be built to last.

Remember to take care of your timber by adding soft felt pads to your furniture legs and avoiding heavy mopping with excessive amounts of water.

If you're feeling inspired and ready for your next DIY update, we've got plenty of other guides to help you get started, like this guide on how to paint skirting boards on hard floors.

FAQs

Because solid wood needs a highly stable base, laying solid wood flooring on underlay isn't usually recommended. Most solid wood is glued or nailed directly to a sturdy sub-floor. However, while you don't use soft underlay, you will absolutely need a damp-proof membrane if you are laying over concrete.

It is not advisable to lay solid wood flooring on chipboard. Chipboard simply isn't robust enough to handle the natural movement and tension of solid wood, and it lacks the necessary damp-proof qualities. If you currently have chipboard, we recommend lifting it or covering it securely with a half-inch plywood sub-floor before starting.

Learning how to lay solid wood herringbone flooring involves a different technique than standard straight planks. While the preparation and sub-floor rules remain the same, herringbone requires setting out a precise central axis line in the room. You must build the zigzag pattern outwards from this centre point to ensure symmetry. Always check the specific manufacturer’s instructions, as the locking mechanisms for herringbone planks can vary.

Solid wood is easy to care for once you know how. Put soft felt pads or castors on the bottom of your chair and table legs to prevent deep scratches. To maintain the superb natural look of the timber, don’t use abrasive cloths or excessive amounts of water to mop. You can keep it looking fresh by using dry soft brushes, vacuum cleaners, and our specially formulated flooring maintenance and cleaning products.