Bathroom Cladding Trims

Bathroom cladding is now seen as a great alternative to tiles when it comes to decorating your bathroom. But it is not as well established as tiles. Because of this many of the installation techniques are unknown.  So there are many questions in people’s minds. Do I need to use bathroom cladding trims? Can it be installed over tiles?  Can it be used in showers?

All bathroom cladding is suitable for use in showers (see Shower Wall Lining for more info). And all can be fitted over tiles (see Panel Over Tiles for more info). This article will concentrate on how and when to use trims in the installation process.

If you are looking to buy trims for cladding they are available online from IPSL*. Here are some examples – click any of the images to find out more:


cladding trims





cladding after - shower mixer




Do I Have To Use Trims?


If you think about it, there are very few trims used when installing tiles (if any) and bathroom cladding is the same.

The main reason for using trims is that they make installation easier. But they are not part of the fixing system

Saying that, check with your manufacturer about the use of trims as there are one or two around that insist that you use them (and their adhesive and their sealants). These tend to be the ones that make wood based systems where moisture getting through to the core causes big problems. But PVC cladding systems are completely unaffected by water.

We much prefer the PVC based cladding systems for several reasons

  1. bathroom cladding is easier to install
  2. it will not warp, swell up or rot
  3. it is much cheaper

Our advice is to choose PVC panels and try and use as few trims as possible. The more trims you use the more you detract from the overall look of the finished project.

But if you think they will make life easier for you then here is what each trim is used for.




Decos Corner Trim 102

Internal Corner Trim

When you panel into the corner of a  room you have several choices. This trim is used to help form the corner and cover up the cut edges. It means that you do not have to be as accurate with your cuts when you use this trim.

An internal corner trim is usually made in two parts. The backplate is fixed to the wall first. The panels are then fitted and the the second part of the trim clipped into place. The panels still need to be sealed into the trim as they are not designed to act as seals.

The alternative to using this trim is to but-join the panels into the corner. This is just the same as you would do with tiles. Use two machined edges for a neat finish and seal with a good quality silicone. Cut off the tongue or groove it is interfering with the join to ensure a nice, snug fit.

A third option is to cut the back of the panel and bend the cladding into the corner. This has some downsides and is not recommended for beginners. See our article on bending panels here for more information.

Decos Corner Trim White 030

External Corners

Most bathrooms will have external corners somewhere in the room. The edges around windows(the reveals) are external corners. If you have boxed-in any pipework this will have an external corner too.

Bathroom cladding panels do not have a finished edge. The ends of the panels are open so the structure of the panel is visible. One vertical edge has a tongue and the other has a groove.

So when the panels are used to form an external corner one or more of these unfinished edges will be visible. Bending the panels to form an external corner is possible but it is even more difficult than an internal corner. So a trim is the best answer.

Most (but not all) internal corner trims are universal. That means they can be used on internal and external corners.  You can also use a plain “L” section trim. This has the advantage of being able to be fitted after the corner has been formed. It is simply suck in place using panel adhesive or silicone. Both of these options will cover up your cut edges and allow you some “slack” when it comes to accuracy.

A very neat solution is to use a tile edge trim. These do not cover up the cuts so you have to be very accurate. But the resultant corner is the best when it comes to appearance. Chose a trim that is the same thickness as the panel – 8 or 10mm

Of all the bathroom cladding trims these are the only ones that are really necessary.

decos white capping trim

Capping Trim

Capping Trim is used for exposed edges. So if you are only half panelling a wall and coming to a stop you would use a capping trim to cover up the edge.

This trim is also used as an edge for ceiling panels. In this instance the back “leg” of the trim is cut away. The trim is then simply stuck in place once the ceiling has been installed.

Other uses are around a door frame if the architrave is not thick enough for the panels to butt up to.

Do not use capping trim at the bottom of panels as it can act like a trough. The pooled water will then run along the trim and find a way out causing a leak. This is especially important in wet areas such as above a bath or inside a shower cubicle.

Decos Coving Trim White

Coving Trim For Ceilings

This trim is used with wall panels to cover up the joint between the top of the panels and the ceiling. It can also be used as an edge to ceiling panels if you you have a tiled wall.

This is another 2-part trim with a backplate that is fixed into position first. The panels come next and then the front section clips into the backplate.

You will need a mitre block or mitre saw for this trim to ensure an accurate fit at each corner. Take your time when mitring – it is all too easy to make a mistake and mitre in the wrong direction. We would recommend buying one or two extra trims just to be on the safe side.

Should I Use A Bath Seal?

These trims fit up behind the panels or tiles. A thin flexible edge then sits on the bath forming a seal.

We have had problems with this type of seal in the past where the flexible strip has deformed allowing water through. They are impossible to remove as they are fitted behind the panels. The whole of the panelling around the bath has to be removed. So exercise caution before using these trims.

Their main purpose is to allow a small amount of movement between the bath and the wall. Our advice would be to try and eliminate the movement rather than accommodate it. Techniques include fitting a batten under the lip of the bath. This prevents the bath from dropping when it is filled with water. Grinding out a channel and plastering the bath into place is an alternative to this.

If you have an existing bath cut lengths of batten to the height of the bath rim. Take the bath panel off and reach under the bath to place the battens (vertically) under the rim. This will help support the bath and prevent it from flexing and dipping.

See our blog for more details on sealing a bath permanently.

Bathroom Cladding Trims – Our Conclusions

We hope this article has gone some way to explain how and where to use bathroom cladding trims. You do not always need to use them especially if you are accurate with your cutting. A simple silicone seal will look neater than a white plastic trim in most cases.

The main thing to remember is that trims are decorative. They are not part of the fixing system or waterproofing system.