The wall with most evidence of damp is made of stone and has a lime render with plaster skim coat on top. With greater hygroscopic qualities than the adjacent cement wall, rendered walls in this area will absorb moisture from showering/bathroom use etc. It is worth noting that a large area of lead flashing with no insulation is sited on the roof, directly above the damp wall.

When the damp patch near the window was excavated, we found a heavy-gauge steel masonry connector, used to tie the new breeze block wall to the existing stone. Doubtless this is causing cold-bridging (the transference of outside temperatures to the inside of the structure) and condensation on the inner wall.

The humidistat extractor fan was set to respond only to very high humidity levels (80% Relative Humidity).

The wall is essentially breathable. A cyclical pattern has been set in motion by the conditions, akin to a weather system. The top of the wall is at a lower temperature than might be expected, which is due to lack of insulation, a large area of exposed lead flashing and a large area of exposed parapet walling in concrete block (concrete with cement render is not able to wick the moisture away at a high enough rate in this situation). The air at the top of the room is moist, and once moisture enters the wall it has no escape route, causing interstitial condensation. Capping stones have been replaced with concrete blocks on top of  damp-proof course, offering no way for moisture to escape, except by leaching back through the surface of the wall into the room.

The ceiling displays a ‘tide mark’ consistent with flooding, which is borne out by the owners’ observation of snow melt in the roof valley breaching  the lead flashing. Also on the ceiling, there is staining consistent with persistent damp, immediately below the points where airbricks have been retrofitted in an attempt to ventilate the roof void. We believe this damp is resulting from interstitial condensation, aggravated by cold air entering through the air bricks.

We found lime render on the damp wall; the damp patch corresponds with damp found in the bathroom. This suggests the wall between the bathroom and bedroom 2 is saturated with moisture.

There is also evidence of a leak in the roof on the chimney breast; no excavation has been carried out as there is evidence of water running down the walls in the crawl space above, i.e. there is a leak, or extreme condensation persistently running down the crawl space wall.

The damp on one of the structural beams was investigated; underneath was bonding coat plaster where two cables had been ‘chased’ in to the wall, surrounded by concrete render. The structural beam showed signs of rust. These findings would suggest the steel beam is ‘cold-bridging’, and that condensation is forming on it and escapingthrough the most permeable route (i.e. through the bonding coat plaster rather than concrete render).

Damp investigated opposite the washing machine revealed concrete render and breeze block underneath. The location of damp (i.e. near a cold draughty door and damp washing) suggests this might be naturally forming condensation.

The damp patches investigated again revealed decorating filler in concrete render, with stone wall underneath. This suggests damp escaping by the easiest and most permeable route.

Investigation here revealed concrete render on a stone/brick wall. Possible rising damp, exacerbated by the restricted air movement from the clothing  hung there. This wall could be easily be completely removed (subject to a structural engineer’s report), and replaced  with a new wall, incorporating a damp-proof course, and high level window to allow natural light into the shower area.

High moisture meter readings were taken from the skirting board in the party wall corner, but this is judged to be due to  levels of condensation, exacerbated restricted air movement caused by furnishings and cold internal surface temperatures, and the suspected low vapour resistivity of the building envelope.

The cement render is very thick in places. The vapour resistivity of cement is comparatively high, and it will trap any moisture within the structure. It would be advisable to minimise the amount of water vapour entering the walls, and maximise the amount able to leave. The thick layers of render have increased the vapour resistivity figure, and made the egress of moisture so slow that the walls can gain moisture faster than they can lose it.

The following is the result of a necessarily brief inspection, and is not an exhaustive report. We would recommend further investigation in order to gain more information before any further work is carried out on the property. As part of that inspection, the central heating system controls could also be checked over.

Regarding the extension in the kitchen wiring: sockets and lights appear to fulfil regulations, but it would be advisable to remove the socket closest to the sink.   

The ring main (sockets) for the rest of the dwelling consists of a single circuit. Best practice would dictate that this should be split into separate circuits for upstairs and downstairs, should the opportunity arise (for instance, during the course of any major works).

The two lighting circuits for upstairs and downstairs use 1 mm cable which does not meet current regulations. Also noted is a bridge between the circuits requiring both circuits to be deactivated in order to make the lighting safe to work on. This must be rectified as soon as possible.

The recently installed consumer unit has the necessary circuit breakers in the event of a problem, however if extra circuits are to be added, it will need to be replaced with a larger unit.

Estimates suggest that the installed solar hot water pre heat system is working at about 37.9% efficiency, saving about 101 cubic metres of gas per year. It may be possible to increase the efficiency somewhat.

As the system is configured, the running time of the pump is used to measure the amount of heat gained. Due to the excessively long pipe-runs, it is possible that the pump may at times be exporting heat back to the roof. The pump may be operating more often than it needs to, and exporting heat from the cylinder to the panel. Whilst this heat is ‘free’ and may even be surplus to requirements, nevertheless, electricity is unnecessarily expended by the pump. Due to conversion losses, carbon emissions are three time greater for electricity than for gas. We would recommend increasing the pump activation temperature differential, reducing the pump running time for preheat collected.

It was also noted that when the gas boiler is producing  hot water and the heating is off, the radiators get hot, suggesting that the zoning control valves are failing to work correctly. This may cause the system to waste more energy than it saves.