Advice Hub

Updated 25 June 2026 | By the MW Profiles Team

If you have ever pulled out a kitchen kickboard and found a damp, swollen MDF panel underneath, you already know why this small part matters. A plinth sealing strip is the cheap, simple bit of trim that sits along the bottom of your kitchen plinth and stops water, crumbs and dust from getting behind it. Fit it properly and your kickboards stay dry, clean and looking new for years.

This guide covers what a plinth sealing strip actually is, which size you need (16mm or 18mm), the colour options, how to fit one in about ten minutes, and the mistakes that catch people out. Whether you are a kitchen fitter doing this every week or a homeowner tackling a first install, you will find a clear answer here.

What is a plinth sealing strip?

A plinth sealing strip is a flexible PVC profile that clips or sticks to the bottom edge of a kitchen or bathroom plinth (the panel that hides the gap under your base units). It has a rigid spine that grips the board and a soft, flexible lip that presses against the floor.

That flexible lip is the clever part. It bridges the gap between the bottom of the plinth and the floor, so spills, mop water and dust cannot run underneath. Floors are rarely perfectly level, and the lip flexes to follow small dips and rises, which keeps the seal continuous along the whole run.

Most plinth panels are made from MDF or chipboard with a laminate finish. The cut bottom edge is the weak spot, because once water reaches that exposed core the board swells and the laminate lifts. A sealing strip protects that edge, which is why it is sometimes sold as a kitchen plinth edge protector.

Plinth sealing strip or kickboard trim: same thing?

Yes. Plinth sealing strip, kickboard trim, kickboard sealing strip and plinth edge protector all describe the same product. "Plinth" is the trade term and "kickboard" is the everyday one, but they are the panel running along the floor under your units. The strip that seals its bottom edge goes by all of these names.

You may also see it called a plastic plinth trim or a clear plinth sealing strip when it is the transparent version. The job is identical: seal the gap, protect the board, keep the area clean.

What size plinth sealing strip do you need?

The size you need matches the thickness of your plinth panel. The two common sizes in UK kitchens are 16mm and 18mm, and most modern plinths are 18mm. A good strip is designed to grip both, which is why you will often see it listed as a 16 to 18mm plinth sealing strip.

If you are not sure, measure the panel thickness with a tape or a digital caliper before you order. An 18mm strip on an 18mm board gives a firm, snug grip. Too loose and the strip works its way off over time, too tight and it can be a fight to push on.

Lengths usually come in 1 metre and 2.5 metre pieces, so you can buy close to your run length and cut to fit. Measure the full length of every plinth section, add the two together, then add roughly ten percent for offcuts and corners.

Expert tip: standard kitchen plinths are around 2.4 metres long, so a single 2.5 metre strip usually covers one full panel with a little to spare. Buy by total run length rather than guessing by the number of units.

Colour options: clear, white, grey and black

Colour matters more than people expect, because a mismatched strip draws the eye straight to the floor line. The aim is for the seal to disappear, not to stand out.

The clear (transparent) plinth sealing strip is the most popular choice, and for good reason. It works against any plinth colour and any flooring, so you do not have to match anything. It is the safe option if you are unsure or if your plinths and floor are different tones. View the transparent PVC plinth sealing strip (16 to 18mm).

Solid colours give a cleaner, more finished line when you want the seal to blend into the plinth itself. White suits gloss white and cream kitchens, light grey works with the popular grey and concrete-effect units, and black is the match for anthracite, dark wood and matt black plinths.

MW Profiles stocks one of the widest colour ranges in the UK for PVC profiles, so whether your kitchen is bright white or deep anthracite, there is a strip that lines up with it.

How to fit a plinth sealing strip

Fitting is genuinely a ten minute job and needs almost no tools. The strip simply pushes onto the bottom edge of the plinth, and the flexible lip does the rest once the plinth is back in place.

What you will need

A tape measure, a sharp utility knife or a fine-tooth saw, and a clean cloth. That is the full list. If your plinth clips to adjustable legs you may also want a screwdriver to refit the clips, but no adhesive is needed for most strips because they grip the board on their own.

Step by step

First, remove the plinth panel by gently pulling it off its clips, or unclip it from the leg fittings. Wipe the bottom edge clean so nothing stops the strip seating fully.

Measure the panel and cut the strip to length with a utility knife, cutting from the rigid side for a clean edge. For internal and external corners, cut each piece to butt neatly against the next rather than trying to bend one strip around the turn.

Push the channel of the strip firmly onto the bottom edge of the plinth, working along the full length so it grips evenly. Then refit the plinth onto its clips. As the panel drops into place, the flexible lip should press against the floor and form a continuous seal.

Stand back and check the lip is touching the floor along the whole run. On an uneven floor you may need to adjust the plinth height slightly so the lip stays in contact without buckling.

Expert tip: for a tidy finish at external corners, mitre the two strip ends at 45 degrees so they meet cleanly. It takes thirty extra seconds and looks far better than a butt joint on a visible corner.

What about plinth corners?

Corners are where most people get stuck, but the strip itself handles them. You do not need a separate corner piece. Instead, cut a length for each run and join the pieces where the plinth turns.

On an internal corner (where two plinths meet in a recess), butt the ends of the two strips together so the lips stay in contact with the floor right into the corner. On an external corner (an exposed end, like a peninsula), a 45 degree mitre on each piece gives the cleanest look.

Take your time measuring before you cut, because corner offcuts are the main reason people run short. This is exactly why we suggest adding ten percent to your total length when ordering.

Where plinth sealing strips are used

The kitchen is the obvious home for these strips, sealing the kickboard under base units against mop water, dishwasher leaks and the daily splashes around a sink. They significantly reduce water ingress to the plinth edge, which is exactly where damage usually starts.

They are just as useful in bathrooms and utility rooms, anywhere a fitted unit sits on the floor and water is around. Vanity units, fitted laundry cupboards and boot-room benches all benefit from the same seal.

Beyond water, the strip keeps crumbs, dust and pet hair from collecting in the gap under the units, which makes cleaning far easier. For families and busy kitchens that alone is often reason enough to fit one.

If your real concern is moisture getting behind the units, it is worth reading our guide on how to stop water getting under your kitchen units, which covers the wider picture alongside the plinth seal itself.

Common mistakes to avoid

The most common error is ordering the wrong size. An 18mm strip will not grip a 16mm board properly and will keep falling off, so always measure the panel first rather than assuming.

The second is forgetting the corners. People buy enough strip for the straight runs and then come up short at every turn. Add ten percent to your total length to cover offcuts and corner joints.

The third is setting the plinth height wrong. If the panel sits too high the lip never touches the floor and the seal does nothing, so check the lip is in firm contact along the whole run once everything is back together.

While you are sealing the lower kitchen, it is a good time to deal with the top as well. Our guide on how to seal the gap between your worktop and wall uses the same idea at counter height and finishes the room off neatly.

Plinth sealing strip FAQ

What is a plinth sealing strip used for?
It seals the gap between the bottom of a kitchen or bathroom plinth and the floor. This keeps water, dust and crumbs from getting behind the kickboard and protects the panel edge from swelling.

What size plinth sealing strip do I need, 16mm or 18mm?
Match the strip to your panel thickness. Most modern plinths are 18mm, but many strips are made to grip both 16mm and 18mm boards, so measure the panel first if you are unsure.

How do you fit a plinth sealing strip?
Remove the plinth, wipe the bottom edge clean, push the strip onto the edge along its full length, then refit the plinth so the flexible lip presses against the floor. No adhesive is usually needed.

Does a plinth sealing strip stop water completely?
No seal is fully waterproof, but a correctly fitted strip significantly reduces water ingress under the units and protects the panel edge, which is where most water damage starts.

What is the difference between a kickboard trim and a plinth sealing strip?
There is none. Kickboard trim, kickboard sealing strip, plinth edge protector and plinth sealing strip all describe the same product. "Plinth" is the trade term, "kickboard" the everyday one.

Can I get a clear plinth sealing strip?
Yes. The transparent version is the most popular because it suits any plinth colour and any flooring, so there is nothing to match.

What colours do plinth sealing strips come in?
Common options are clear, white, light grey and black, which cover most kitchen colour schemes from gloss white to anthracite.

How long is a plinth sealing strip?
They are usually sold in 1 metre and 2.5 metre lengths. A single 2.5 metre piece typically covers one standard plinth panel with a little to spare.

Can I cut a plinth sealing strip to size?
Yes. Cut it to length with a sharp utility knife or a fine-tooth saw, and mitre the ends at corners for a clean finish.

Do I need adhesive to fit a plinth sealing strip?
Usually not. The channel grips the bottom edge of the board on its own. On very smooth or worn edges a little adhesive can add security, but most installs need none.

How do you deal with plinth corners?
There is no separate corner piece. Cut a length of strip for each run, butt the ends together at internal corners and mitre them at 45 degrees at external corners for a clean finish.