17 Flats & 9 Houses
12 buyers, 6 vendors, 7 landlords, 1 owner occupier (Covid vaccinated).
Click for case name for survey illustrations and Survey Tips. See abbreviations below.
Summary for Feb ’21 London, damp surveys:
- Groundwater (rising damp) 0%,
- Rain 42%,
- Mains leak 12%,
- Vapour 77%,
- Hygroscopic salts (vapour) 15%,
- Previously damp-proofed (still damp) 70%.
Explanations & abbreviations
b = damp at base of the wall at or near ground level
m=mould,t=damp at top of wall
p=damp in patches
c=crystallised (surface) salts
Period | Attachment | Floor if flat
p = Pre-Georgian
c = Church or similar conversion
g = Georgian
v = Victorian
e = Edwardian
t = Twenties, Thirties (1920 / 30’s)
m = modern (post war)
t = Terraced
e = End of terrace
s = Semi-detached
d = detached
Flats – floors
Based on susceptibility to damp i.e. ground or roof.
– = lower-ground floor or basement
0 = ground-floor
# = floor number
9 = top floor (exposed to roof)
Previous damp proofing
i = Injected thixotropic siloxane cream or silicone into base of wall as "DPC"
s = Slurry used to hide symptoms of damp, with impervious plaster.
d = Dry lined, also used to hide symptoms of damp, by separating plaster from wall.
t = Tubes, mainly Dutch, such as sold by Frank Schrijver, tends to also include damp hiding slurry.
0 = No damp-proofing.
– = N/A – Not appropriate, perhaps because a flat without a ground-floor.
RICS / PCA (contractor) misdiagnosis
It is normal for a buyer to instruct a RICS surveyor to inspect a property during the process of buying it. Most RICS surveyor are good.
Some inexperienced surveyors will misdiagnose a high damp meter reading at the base of a wall as Rising Damp, without any additional evidence. It is for this reason that such a high proportion of properties have been damp proofed, yet as statistically about 70% (Damp Surveys – London), of those same properties have ongoing damp issues.
PCA contractors specialise in a specific field. If they are instructed to quote for Rising Damp, then they will do that, without looking for evidence (other than a high damp meter reading) or for other sources of dampness. How can blame them, they are incentivised to find Rising Damp.
r = RICS surveyor
p = PCA contractor
Root cause (as opposed to symptoms)
g = Groundwater
r = Rainwater
l = Mainswater
v = Vapour
h = Hygroscopic salts (vapour)