Determining the approach for retrofit insulation and barrier materials requires some knowledge of how walls are framed, sheathed and integrated into floors and roof structures.

Important Safety Considerations for Wall Assemblies:

• Walls are made from common components: horizontal plates, vertical studs and posts, built up beams and headers that span openings, blocking, and sheathing.
• The size, spacing, fastening and type of wall system parts are determined by the building code OR by proprietary, engineered component manufacturers (i.e. laminated veneer lumber (LVL))
• Wall systems are part of the LOAD BEARING capacity in a building - they carry live and dead loads from above, down through studs, plates, beams / headers, floors, foundation walls and footings and out to the ground.
• Sometimes in older buildings, walls bow inwards or bulge outwards, depending on the type of structure and the age / condition of the building. Sighting down the exterior of a building from a distance may reveal these issues, followed by a formal building survey to discover the root cause of the deformation.
  
• Water stains on walls may point to infiltration from horizontal elements such as doors, windows and roof junctions.
• Operation of doors and windows may be affected by structural elements in walls that are deteriorating or failing.