Mendes External Joinery Treatment, Installation & Maintenance Guidelines
🛡️ External Products – Important Information
Mendes engineered external doors must be protected from direct sun and rain. This should be achieved using a porch, canopy or recessed opening of ideally 1.5 metres.
If this protection is not provided, door performance will be compromised and any guarantee will be surrendered.
🎨 Finishing & Sealing (External Doors)
- A minimum of three coats of a suitable finishing product must be applied.
- All faces, edges and cut-outs must be fully sealed prior to installation.
- A weather bar must be fitted externally at the bottom of the door.
- Avoid very dark colours (including black) as they absorb heat and can cause cracking or excessive shrinkage.
- External oak doors require a finish containing UV protection. Clear products usually do not contain UV inhibitors — always check with the finishing manufacturer.
🎨 Approved Finishing Products (External Oak Veneered Doors)
For Mendes external oak veneered engineered doors and frames, it is strongly recommended that you contact the manufacturer of your chosen finishing product prior to application.
When doing so, you must clearly state that the product being treated is an external oak veneered engineered door, frame or joinery item, to ensure the finish selected is suitable for this construction type.
Mendes recommend the use of a solvent-based or oil-based finishing system only. Water-based products are not recommended for external oak veneered engineered doors.
Once a finishing system has been selected, you must:
- Follow the paint or stain manufacturer’s application instructions in full
- Use only that manufacturer’s products throughout the finishing process
- Not mix brands between base coats, primers and top coats
Failure to follow the above guidance may result in inadequate protection, compromised performance and the manufacturer’s warranty being invalidated.
🚫 Unsuitable Finishes
The following finishes are not suitable and will invalidate warranties:
- Waxes
- Oils
- Polishes
- Water-based sealants
🔧 Future Maintenance
- Ensure the door remains sealed at all times to prevent moisture movement.
- If lacquer cracks, scratches or scuffs, re-seal immediately.
- If shrinkage lines appear around panels, reseal exposed timber straight away.
- Check external glazing sealant — if brittle or cracked, reseal with a suitable clear waterproof external mastic.
- Wash the door with warm water and mild detergent at least every two years and apply a further coat of finish.
👷 Professional Installation & Liability Notice
If a professional is instructed to treat or install the door, it is the customer’s responsibility to ensure compliance with all Mendes guidelines.
Mendes shall not be held responsible for incidental work, expenses or defects caused by incorrect installation or workmanship.
In the event of a confirmed manufacturer defect, liability is limited to the price paid for the defective item only.
💬 Need Help Before You Install?
Contact us prior to installation to avoid costly mistakes.
📧 sales@doorphoria.co.uk