Moisture and vapour: design task for walls and façades
In an external envelope, moisture and vapour becomes visible where the substrate, insulation and finish meet.
In walls and façades, moisture and vapour requires continuity of the insulation layer; also check interfaces around openings and compatibility with finish layers.
Moisture and vapour: inputs for walls and façades
Before assessing moisture and vapour in walls and façades, obtain moisture direction, barrier positions, sealant specification and every penetration detail.
For walls and façades, the verifiable moisture and vapour requirement is to verify joints, interfaces, penetrations and the compatibility of sealing materials separately.
Moisture and vapour: application boundary in walls and façades
In walls and façades, moisture and vapour has an important boundary. Low vapour permeability cannot correct an unfilled joint or a break in external waterproofing.
For moisture and vapour in walls and façades, address this specific risk: local breaks in the layer.
Moisture and vapour: evidence for walls and façades
For walls and façades, the moisture and vapour source states: The D130 technical data sheet states a water-vapour permeability of no more than 0.003 mg/(m·h·Pa).
For moisture and vapour in walls and façades, apply this principle. Moisture protection depends on system continuity: product properties cannot compensate for open joints or a defect in an adjoining layer.
Moisture and vapour: detailing for walls and façades
The walls and façades drawing develops moisture and vapour through two decisions: the panel layout; then fixing method and sequence of finish installation.
For moisture and vapour in walls and façades, dimensions and interface materials belong in the design, not in an improvised site decision.
Moisture and vapour: accepting work in walls and façades
Acceptance of moisture and vapour in walls and façades starts by matching delivery labels, drawings and the installed layout.
For moisture and vapour in walls and façades, close the identified risk with a photograph, measurement or record, not a verbal explanation.
The final walls and façades criterion for moisture and vapour is that moisture protection forms one continuous line through corners, supports and transitions.
Moisture and vapour: installation in walls and façades
The installation rule for moisture and vapour in walls and façades is to verify substrate flatness.
During walls and façades work concerning moisture and vapour, inspect filled joints under raking light and record interfaces before covering.
Moisture and vapour: conclusion for walls and façades
In walls and façades, foam glass delivers its moisture and vapour benefit through a coordinated detail, not one schedule entry.
The walls and façades workflow for moisture and vapour is to evidence the property, issue the detail, accept installation and retain concealed-work records.