|Lintel Materials and damp proof courses
Lintels having integral cavity tray features and meeting the surface protection criteria laid out in BS 5977 & BS EN 845-2 may be installed in outer cavity walls without a seperate DPC.
Essentially, Hot dip Galvanised and Stainless Steel Lintels are the only lintels that can meet this requirement without onerous additional paint systems being applied.
Hence Harvey Steel Lintels only offer the option of integral cavity tray features with their stainless steel range of lintels.
This means that you can make additional on site savings using stainless steel lintels over pre-galvanised lintels through not having to install a seperate DPC, and your DPC integrity is guarenteed!
||A caution regarding solid external wall
Not all external walls are cavity walls, there are plenty of external solid walls!
If the external wall is to have a dry inner and damp outer, then a DPC would probably be installed anyway, but there are instances of walls that are likely to be damp on both sides, and still require a lintel, such as courtyard openings etc.
In these situations, you must still install a DPC over regular pre-galvanised lintels unless they have additional paint systems applied!
The DPC in these cases is only required to protect the Lintel. This is due to the inherently low corrosion resistance of pre galvanised lintels.
Many builders would omit to install DPCs in this case, so specifiying stainless steel lintels avoids potential disaster!