LED profile on its own is not waterproof.  You can purchase some that will advise that they are but a sealant will need to be applied to make the profile waterproof.  LED profile is made from extruded aluminium and this is designed primarily for heat dissipation to house LED strip lighting. The aluminium material will be rust-resistant and will help to reduce the risk of dust or exterior factors getting to the LED strip.  However, there will be small gaps within the profile even with a cover on meaning it cannot be defined as waterproof.  

How do you make the profile installation waterproof?

To achieve a waterproof installation you will need to focus on all of the components within your setup.  This includes the aluminium channel; the diffuser, the end caps, and the LED strip itself.

1. The Aluminium Profile (The Channel)

• Standard Profiles: These are open systems and will have small gaps through the seam where a diffuser would slide into place.  Water can get through these gaps and this will also offer a lower protection against dust compared to a sealed profile.
• Sealed Profiles: Specialized profiles are available that are designed with deeper channels and tight-fitting diffusers to make it easier for them to be sealed.  They will still require a waterproof sealant to be added to the profile to achieve a reliable IP rating of IP65 or above. 

2. The Diffuser (The Cover)

• The diffuser is usually made of polycarbonate or PMMA plastic and this does not seal water out effectively by itself. Its primary function is to aid with light diffusion and to offer dust protection.
• If you need the setup to be waterproof you will need to seal the connection between the profile and the diffuser. 

3. The End Caps

• End caps are available with or without holes.  The holes are there for wires to be connected through the profile but this means that they will not offer waterproof protection.  To make sure the setup is waterproof you will need to use end caps that do not have any holes.  It is also recommended that you use sealant on these end caps and any wire exits to ensure it will be fully waterproof.

4. The LED Strip

• You will need to make sure that the LED strip you purchase is also IP65 rated to ensure waterproof protection.  An IP65 rating will mean that your LED strip is splash proof and suitable to use in bathrooms or outdoors areas where being rained on directly will not be an issue.
• IP20/IP33: This rating will mean that the strips are not waterproof and only for indoor/dry use.
• IP67/IP68 (Fully Encased/Submersible): If the LED strip and profile will be exposed to heavy rain or submersion you will need to purchase IP67/IP68 rated strip.

Sealing Process Steps (A General Guidance)

1. Place the IP65 or above rated LED strip inside the profile.
2. Route the power cable through an appropriate hole in one end cap and use a cable gland to make a secure seal.
3. Apply a bead of silicone sealant along the entire inside edge of the profile channel where the diffuser will sit.
4. Apply silicone sealant to the edges of the end caps and securely fix them to the ends of the profile.
5. Apply a generous amount of silicone sealant around the wire exit point on the end cap.
6. Slide the diffuser in place onto the profile and make sure that the silicone creates a tight seal.
7. Allow the sealant to fully cure according to the manufacturer's instructions before completing the installation.