Further wording provided as a guide to strengthen your documentation:
Exterior Timber Joinery
Care and Protection
Exterior timber joinery is a premium product, which requires a level of protection to enhance the properties of the product.
The minimum protection is as follows:
All Joinery items must be sealed on all 6 faces prior to installation including hardware penetrations.
Oil based systems only to be used.
4 coat system.
The bottom and top of the Sashes and Doors must be sealed.
Appropriate flashing must be installed.
Joinery with wet plaster must have at least two protection coatings prior to plastering.
Dark colours void any warranty.
If you choose to ignore these recommendations, the warranty is void.
Use neutral cure sealants only.
No tinted putty to be used for exterior use.
Timber glass beads should be fitted using non ferrous fittings.
No glass to be installed unless rebates have been primed or sealed.