Buffering Dampness in buildings

Buffering of damp vapour in buildings is a significant problem in the performance of ground floor flats. The high proportion of severe condensation and mould growth problems (I have observed) occur in ground floor flats.

Within a building, you have an under pressure and a balanced area (generally at the midpoint) and at the top the overpressure area (the balance area will vary due to air leakage in the building).

In a two-storey building, the Air buffer is quite large it’s about 5 m high, In a ground floor flat, the air column is only 2.4 m high.

As you see the potential for air buffering in the single-storey property is much lower and therefore it’s more sensitive to excess moisture generation.

Buffering using wall and floor surfaces may be problematic as the occupier will want to cover the surface with decorative coverings.

To give the building a good chance of buffering the excess moisture vapour heat the property to an ambient 15oC. This will extend the time before any excess moisture will condense (Dew point) on walls and alow low-level ventilation to dilute the moisture in the building’s atmosphere.

Excess water condensing on window

Avoid sealed laminated flooring, carpeting and curtains etc will absorb and release moisture as ventilation dilutes the air in the home.

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