Partial Fill

Partial fill cavity walls keep a clear residual cavity between the insulation and the outer leaf, making them a robust choice where walls face severe wind-driven rain. This category includes 150mm partial fill cavity details, stone-faced cavity walls and walls using the SureCav cavity spacer system. Junctions covered include window heads, cills and jambs, eaves, flat roof parapets, a level threshold, ground bearing slabs and beam and block floors.

When should I use partial fill instead of full fill? Partial fill is often preferred in more exposed locations because the clear cavity helps manage wind-driven rain. Approved Document C and the UK exposure zone map are the starting point for deciding.

What is SureCav? SureCav is a manufacturer’s cavity spacer system. These details show it in stone-faced partial fill cavity walls.