If an opening is formed in a wall, the structure above the opening, even if it is relatively small, will need to be supported. Lintols are normally used to provide such support, in one of two ways:
1. One lintol (usually made of steel, with insulation integral to it) that supports both the inner and outer leaf of a cavity wall construction. These usually also serve as a cavity tray which directs moisture from the cavity through the outer skin of the wall construction
2. Two lintols (made of steel or concrete), one supporting each leaf of a cavity wall construction. Separate thermal insulation and a cavity tray are likely to be required.
With solid walls it is good practice to use a lintol where insulation can be installed to avoid condensation.
All lintols should have a suitable bearing onto the wall at each side of the opening. It is best to consult with the manufacturer or an engineer for the correct size lintol and bearing.
This is an introductory guide and is not a definitive source of legal information. Read the full disclaimer here.
This guidance relates to the planning regime for England. Policy in Wales may differ. If in doubt contact your Local Planning Authority.