Wood to Tile Threshold: Choosing and Fitting the Right Trim

A wood to tile threshold is the trim that covers the join where a timber or engineered wood floor meets a tiled one, usually at a kitchen, bathroom or hallway doorway. It has to hide a gap, cope with any difference in height, and survive daily foot traffic. Choose it by measuring the finished height of both floors, leaving a movement gap between them, and buying a solid metal profile that will not bend, split or dent.

TL;DR

• Measure the finished height of both floors before you buy. A level join needs a flat bar. A step needs a sloped or reducer-style profile.
• Wood and tile move at different rates, so leave a movement gap and cover it with a threshold. Do not lock the trim rigidly to both surfaces.
• Solid brass with a powder-coated finish stays straight and keeps its look in a busy doorway. Cheaper trims tend to bend, split or dent.
• Order a free sample to check the finish against your floor before committing.

Table of Contents

• Why this doorway needs more thought than most
• Step one: measure the height difference
• Step two: leave room for movement
• Step three: choose the profile
• Step four: choose a material that lasts
• Step five: fit it properly
• Our view on this doorway
• Our range for wood-to-tile joins
• Common mistakes to avoid
• A note on accessibility
• FAQ
• Sources

Why this doorway needs more thought than most

Wood and tile are close to opposites. Tile is rigid and barely moves. Wood takes up and gives off moisture, so it swells and shrinks through the seasons. Where the two meet, something has to absorb that difference.

The Tile Association is blunt about it. In its note on the 2024 revision of BS 5385 for wall and floor tiling, it urges installers to take movement joints seriously. The same logic applies at a doorway: if the junction has no room to move, the stress goes into the weakest point, which is often a tile edge or a floorboard.

BAL, a UK tile adhesive manufacturer, explains that dimensional changes from environmental conditions can cause bulging, cracking and loss of adhesion in tiled installations. A threshold is not just decoration. It is the cover for a joint that is meant to move.

There is a second job too. The edges of both floors are raw. Cut tile and sawn boards look rough, and a good threshold hides both.

Step one: measure the height difference

The most common mistake is buying a trim before the floors are finished. Tile thickness, adhesive bed, backer board and underlay all add up, and the wood floor may sit higher or lower than you expect.

Once both floors are laid, or at least dry-laid, do this:

1. Lay a straight edge across the doorway, resting on the higher floor.
2. Measure the gap beneath it at the lower floor, in millimetres.
3. Measure the width of the doorway opening, and the width of the gap between the two floors.
4. Note the depth of the door frame or architrave you must fit around.

The result tells you which kind of profile you need:

If you are fitting for a client and the slope is awkward, our guide for fitters on three measurements for sturdy sloping floor thresholds walks through exactly what to record on site.

When the step is too big

Sometimes the difference is too large for any trim to handle comfortably. A steep slope is a trip hazard, and it looks clumsy. In that case, it is better to deal with the floor itself before trimming: building up the lower surface with a suitable base, or adjusting the thickness of the underlay, can reduce the drop so that the threshold only has a small job to do. This is a decision for whoever is laying the floor, ideally before the tile adhesive is down.

Step two: leave room for movement

Tile installers talk about movement joints, and for good reason. The 2024 revision of BS 5385-3, the code of practice for floor tiling, was published by BSI on 31 May 2024, and it covers the design and installation of ceramic, stone and terrazzo floor tiling. The Tile Association’s tiling guide describes movement joints as the means of absorbing movement from shrinkage, heat expansion and contraction or vibration, so that tiles and grout do not crack.

For your doorway, the practical points are these:

• Do not grout the junction. Grout is rigid. A flexible sealant or a trim that covers a gap is the right treatment.
• Keep the gap clear. Do not pack it with adhesive or fill it solid with mortar.
• Check what your tiler specified. If the tiling was done to current practice, a perimeter movement joint is likely already there at the doorway. Your threshold should cover it, not fight it.
• Follow the wood floor maker’s expansion gap guidance. Timber needs its own space at the edges, and the threshold has to cover that too.

The usual approach in a doorway is a bar that sits over the gap. It is fixed down into the subfloor or fixing channel on one side, so the other floor can still move slightly beneath the cover. Fixing a single rigid piece hard to both a tiled floor and a floating wood floor is a common route to a cracked tile or a lifted board.

If your wood is a floating floor, such as laminate or engineered board on underlay, the whole floor expands as one piece, so the threshold matters even more. Our laminate flooring threshold strips are made for exactly that situation.

Step three: choose the profile

Profiles are named differently by different suppliers, but they fall into a few shapes.

Flat threshold bar

A flat bar, sometimes called a door bar or cover strip, sits across the join when both floors are at the same height. It is the cleanest look and the easiest to fit. It suits a hallway where the tiling and the boards were planned together.

Sloped or reducer bar

When the wood is higher than the tile, or the other way round, a bar with a slope bridges the difference. Look for one wide enough that the slope is gentle. A short, steep ramp is the one that catches toes and trolley wheels.

Wide and extra-wide bars

Where floors are uneven or the join is not perfectly straight, a wider bar covers more of the mismatch. Our floor transition strips for uneven floors are designed for that job.

Self-adhesive or screw-fixed

Adhesive-backed bars are quick and leave no screw heads on show, which suits some light-traffic areas. In a busy doorway such as a kitchen or hallway, a mechanically fixed bar is the sturdier option. Whichever you choose, make sure the fixing goes into the subfloor or a fixing base, not just into the surface of the finished floor.

Step four: choose a material that lasts

This is where many people save a few pounds and regret it. A doorway takes more punishment than almost any other part of a floor: shoes, vacuum cleaners, pet claws, furniture being moved, and in kitchens and bathrooms, water.

Thin trims made from soft or light materials tend to give in. Wooden strips split along the grain or scuff at the edges. Plastic and rubber trims warp, discolour and lose their grip. Thin aluminium bends when someone steps on the edge and dents when something heavy is dropped on it. Once a trim is bent or split, it cannot be straightened, and it needs replacing.

That is why we only make and sell solid brass. Each bar is powder coated and hand finished in the UK, and it will not split, bend or dent in the way those cheaper trims do. It is a heavier product, and it feels it when you pick it up. Fitted once, it is meant to stay put.

On a wood-to-tile doorway, a metal bar has another advantage. It looks deliberate. The bar’s colour can pick up the tone of your hinges, door handles, radiator valves or the grout, which makes the doorway look designed rather than patched.

Matching the finish

We offer ten finishes. When you are choosing, think about what the bar needs to relate to:

• The wood. A warmer metal tone suits oak and walnut. A cooler, paler finish sits better with ash, grey-washed boards or pale engineered wood.
• The tile. A neutral tone that echoes the grout line tends to look calmer than a strong contrast.
• The ironmongery. If your door handles and hinges are in a particular finish, matching it ties the room together.

Because colour on a screen is never quite the colour on your floor, we offer free samples. Hold one against both surfaces in the actual light of the doorway before you order.

Step five: fit it properly

Fitting a threshold is a small job, but a precise one. Here is the order we recommend.

1. Check both floors are finished and clean. Remove dust, adhesive and debris from the gap.
2. Dry-fit the bar. Hold it in the doorway to confirm the length and that it sits centrally over the gap.
3. Cut to length. Measure twice. Use a fine-toothed saw suited to metal, and file the cut end smooth.
4. Mark and drill the fixing points. Mark through the bar onto the subfloor or fixing channel, not the tile surface where you can avoid it.
5. Fix it. Drill through the bar, and where you are going into a solid base, use a suitable plug and screw. Tighten until the bar sits firm without being forced.
6. Check the gap. Make sure the wood side still has room to move beneath the bar.
7. Finish with sealant if the situation calls for it. In a bathroom or kitchen, a bead of flexible sealant along the tile edge keeps water out of the joint. Use a product suited to the tile and the bar.

If you want a step-by-step companion, our guide on how to fit carpet door bars covers tools, marking and fixing in detail, and most of it applies equally to hard floors.

Tiling on a timber floor

If you are tiling over a wooden subfloor, remember that timber moves more than concrete. BAL has a technical note on tiling to timber floors, which warns that some timber boards on the market are not suitable to receive ceramic tiling. Get that right first, because no threshold will rescue a tiled floor that is moving on its base.

Our view on this doorway

We see the same pattern again and again. Someone has laid beautiful boards and spent a lot on the tile, then picked up a thin strip at the last minute because it was cheap and close to hand. Within a year it has bent at the corner, the finish has worn through, and the doorway is the first thing you notice.

Our advice is to treat the threshold as part of the floor, not an afterthought. Measure after the floors are down, allow for movement, pick a profile with a gentle slope, and buy a bar that will not give up. Solid brass costs more than a light strip, but you only fit it once, and it is the part of the floor that people step on most.

If you are a fitter or builder, the same applies. A bar that holds its shape means fewer call-backs, and a clean finished doorway is what customers remember when they look at your work.

— Matt

Our range for wood-to-tile joins

For a wood-to-tile doorway, the most relevant bars sit in our hardfloor to hardfloor trims category. At the time of writing, these are priced as follows:

Each is solid brass, powder coated and hand finished in the UK. Prices vary with size and finish. If your doorway has a step, start with our transition strips for uneven floors, and if you are not sure which profile suits, ask for a free sample first.

Common mistakes to avoid

• Buying before measuring. The height difference is only known when both floors are finished.
• Fixing through both floors. This stops them moving independently and cracks tile or lifts boards.
• Filling the gap with grout. It is rigid and will crack.
• Choosing a steep, short slope. It looks neat on the shelf and feels awkward underfoot.
• Ignoring the door. Check the bottom of the door clears the bar once fitted.
• Skimping on material. A bar that bends is worse than no bar at all.

A note on accessibility

If the doorway is part of an accessible route, for example in a commercial or public building, the height of any threshold is regulated. Approved Document M, Volume 2, says that at accessible entrances the threshold should be level or, where a raised threshold is unavoidable, no more than 15mm in total height. That provision covers entrances, so check with your building control officer or designer for internal doors in your own project. In a private home, the rules are not as strict, but a gentle profile is still kinder to everyone, including anyone with a pushchair, walking aid or wheelchair.

FAQ

Can I put tile directly on wood?

Sometimes, but only if the timber base is rigid, dry and suitable for tiling. Many boards are not, and a flexing floor will crack tiles and grout. Check the guidance in BAL’s note on tiling to timber floors, and ask your tiler to confirm the base before any adhesive goes down.

How do I transition from carpet to tile in a doorway?

Use a bar designed for the join, with a gripping edge on the carpet side and a cover on the tile side. Our carpet to tile threshold and carpet to tile transition strip ranges are made for that, with the second suiting a height difference.

What can I use instead of a transition strip?

A flexible sealant alone can work in a narrow movement joint where both floors are level, but it offers no protection to the edges and wears quickly in a busy doorway. A solid threshold bar covers the gap, protects both edges and gives a finished look, which is why most fitters use one.

Should the threshold be fixed to the wood or the tile?

Fix it to the subfloor or a fixing base, not rigidly to both surfaces. That lets the wood and tile move independently beneath the cover, which reduces the risk of cracking and lifting over time.

Sources

• TTA Urges Awareness On Updates To The British Standard For Wall & Floor Tiling, The Tile Association
• TN 09.23 Types of Movement in Tiling Installations, BAL
• BS 5385-3:2024, BSI Knowledge
• Tiling Guide, movement joints, The Tile Association
• TN 23.24 Tiling to Timber Floors, BAL
• Approved Document M: Access to and use of buildings, Volume 2, GOV.UK

Recommended

• Tile To Tile Threshold
• Wood Door Bar Threshold
• The right engineered wood threshold, chosen and fitted correctly