Moisture and vapour: design task for flat roofs
In a flat-roof build-up, moisture and vapour starts at falls and penetrations and ends with acceptance of concealed layers.
In flat roofs, moisture and vapour requires load distribution; also check drainage and interfaces at parapets and penetrations.
Moisture and vapour: inputs for flat roofs
Before assessing moisture and vapour in flat roofs, obtain moisture direction, barrier positions, sealant specification and every penetration detail.
For flat roofs, 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 flat roofs
In flat roofs, 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 flat roofs, address this specific risk: standing water.
Moisture and vapour: evidence for flat roofs
For flat roofs, 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 flat roofs, 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 flat roofs
The flat roofs drawing develops moisture and vapour through two decisions: edge protection and roof-drain details; then falls.
For moisture and vapour in flat roofs, dimensions and interface materials belong in the design, not in an improvised site decision.
Moisture and vapour: accepting work in flat roofs
Acceptance of moisture and vapour in flat roofs starts by matching delivery labels, drawings and the installed layout.
For moisture and vapour in flat roofs, close the identified risk with a photograph, measurement or record, not a verbal explanation.
The final flat roofs criterion for moisture and vapour is that moisture protection forms one continuous line through corners, supports and transitions.
Moisture and vapour: installation in flat roofs
The installation rule for moisture and vapour in flat roofs is to work on a dry substrate.
During flat roofs work concerning moisture and vapour, inspect filled joints under raking light and record interfaces before covering.
Moisture and vapour: conclusion for flat roofs
In flat roofs, foam glass delivers its moisture and vapour benefit through a coordinated detail, not one schedule entry.
The flat roofs workflow for moisture and vapour is to evidence the property, issue the detail, accept installation and retain concealed-work records.