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Moisture, vapour and foam glass in foundations and below-grade structures

Moisture and vapour for foundations and below-grade structures: evidence, application limits, detailing and acceptance.

In brief: moisture and vapour for foundations and below-grade structures. The project outcome is that moisture protection forms one continuous line through corners, supports and transitions.

Moisture and vapour: design task for foundations and below-grade structures

Below grade, moisture and vapour must be coordinated with waterproofing, soil pressure and the backfilling sequence.

In foundations and below-grade structures, moisture and vapour requires backfilling and waterproofing protection; also check moisture conditions.

Moisture and vapour: inputs for foundations and below-grade structures

Before assessing moisture and vapour in foundations and below-grade structures, obtain moisture direction, barrier positions, sealant specification and every penetration detail.

For foundations and below-grade structures, 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 foundations and below-grade structures

In foundations and below-grade structures, 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 foundations and below-grade structures, address this specific risk: mechanical damage during backfilling or incompatibility with the waterproofing system.

Moisture and vapour: evidence for foundations and below-grade structures

For foundations and below-grade structures, 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 foundations and below-grade structures, 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 foundations and below-grade structures

The foundations and below-grade structures drawing develops moisture and vapour through two decisions: backfilling sequence and the transition to the plinth; then waterproofing type.

For moisture and vapour in foundations and below-grade structures, dimensions and interface materials belong in the design, not in an improvised site decision.

Moisture and vapour: accepting work in foundations and below-grade structures

Acceptance of moisture and vapour in foundations and below-grade structures starts by matching delivery labels, drawings and the installed layout.

For moisture and vapour in foundations and below-grade structures, close the identified risk with a photograph, measurement or record, not a verbal explanation.

The final foundations and below-grade structures criterion for moisture and vapour is that moisture protection forms one continuous line through corners, supports and transitions.

Moisture and vapour: installation in foundations and below-grade structures

The installation rule for moisture and vapour in foundations and below-grade structures is to accept the substrate before covering it.

During foundations and below-grade structures work concerning moisture and vapour, inspect filled joints under raking light and record interfaces before covering.

Moisture and vapour: conclusion for foundations and below-grade structures

In foundations and below-grade structures, foam glass delivers its moisture and vapour benefit through a coordinated detail, not one schedule entry.

The foundations and below-grade structures workflow for moisture and vapour is to evidence the property, issue the detail, accept installation and retain concealed-work records.

Topics: foam glass, foundations, moisture protection, NEOPORM

This material is informational. Final decisions on thickness, details, fixings and compatible compounds must follow the project documentation, current technical data sheets and the conditions of the specific facility.