Radon Barrier Protection Strategy - Necoflex

Sealing Walls and Designed Cavities


Sealing Walls and Cavities Step 1

 Fig 1

Sealing Walls and Cavities Step 2

 Fig 2

Sealing Walls and Cavities Step 3

 Fig 3

 Sealing Walls and Cavities Step 4

  Fig 4

Sealing Walls and Cavities Step 5

 Fig 5

 Sealing Walls and Cavities Step 6

  Fig 6

 Sealing Walls and Cavities Step 7

Fig 7

 Sealing Walls and Cavities Step 8

 Fig 8


Seal all corners using Easi-Load™ Radon Corner Assembly kits. The standard kit includes 1 internal section, 1 external section and 1 corner cap section. Kits are also available to suit T-shaped junctions.

The internal and external sections should be trimmed if necessary to suit the height of the block or upstand (fig 1 & 2).

Once these are in position, slide the corner cap down fully over the top of the block, ensuring both edges are lapped to the outside of the internal and external sections (fig 3). Remove the release paper from the settlement sealant strips which are pre-applied to the inner walls of the corner cap. Apply firm pressure along the entire length of the sealant strips to ensure a complete seal has been achieved.

Remove all the release paper tabs from the settlement joints and angle fillets. Apply two strips of Monobond RT™ radon resisting tape across the entire assembly (fig 4 & 5). Ensure each strip is placed across the angle fillets and settlement joint. Both strips should lap fully at the point where they meet (on the base of the internal corner section). Leave backing paper in place for the time being.

Easi-Load™ Radon DPC should be placed along the entire length of each wall (fig 6). It should be dressed down to meet the sand-blinding/substrate and return horizontally a minimum of 100mm to facilitate lapping and sealing with the Monarflex radon barrier membrane. When used to seal external cavity walls, Easi-Load™ Radon DPC should cross the entire cavity and full width of the outer leaf.

All radon barrier DPCs should exit above external ground level. Where the length of radon DPC downstand in the cavity is deemed insufficient, an additional stepped DPC should be added (see Figure 10 in NSAI Agrement Certificate 09/0380 – available for download here).

To seal the Easi-Load™ Radon barrier DPC to the Easi-Load™ Radon Corner Assembly, remove the backing paper from the previously applied radon resisting sealant tape and carefully position the Easi-Load™ Radon barrier DPC, ensuring full coverage of each strip. Using a hand roller, apply firm pressure over both joints and ensure there are no gaps.

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