Tooltip Categories: FACTS

Facts use to help professional and property owners to determine root of causes and improve outcomes.

FACT: houses contain 4 litres of water as vapour

Houses contain about 4 litres of water as vapour. A normal house typically contains 10 grams per cubic meter at 65%RH at 20°C. A 2.5M high room and foot print of a house is 150M2 = 375 x 10 = 3,750 g or 3.7 litres. (1,000 grams in a litre)

FACT: in Scotland drying facilities

In Scotland drying facilities are required to be provide to tenants. Most landlords provide a drying rack in the bathroom while ensuring adequate bathroom ventilation. there’s no such legal requirement in UK. However it is wise to provide facilities, as you have done, and ask the tenants to use them.

FACT: dampness in bricks reduces

Dampness in bricks reduces insultion by a factor of about 50%, so even if the rain doesn’t actually penetrating through the wall, the increased susepticibility of one a section of wall to become damp, reduces internal temperature increasing the risk of condensation and mould. A good example is where the uppeer section of wall is painted or render, and the lower section exposed, resulting increased dampness on the external skin causing bricks to lose heat..

FACT: solid floors are prone to condensation

Solid floors are prone to condensation because of heat loss close to the ground. The impermeable surface acts as an amplifier, resulting in water under the skirting board. It is also common for plasters to allow the plaster to touch the solid floor. plaster is absorbent. The result is often misdiagnosed as rusing damp. The simpest solution is 1) improve ventilation, 2) seal up at the base of the skriting board, 3) cut the plaster back at the base of the wall by 10 – 20mm back to brick (chisel, grinder or better still Oscillating Multi Tool, such as Bosch), 3) Run a bead ~10mm of a absorption reducing Thixotropic cream such as DryZone by Safeguard (Amazon etc), along the exposed brick. Replace the skirting board.

FACT: 90% of vapour remains

90% of vapour remains in a bathroom after a shower has been switched off and the occupier left the room. That is why it is so important to keep the extractor fan running for 30 minutes. Strangely most extractor fan manufacturers set fans up with a 1 or 5 minute default and builder’s or electricaians, rarely know to change the setting. This shortcoming probably accounts for more isdiagnosed rising damp than any other cause of dampness, probably accounting for £100M of wasted economic activity in the UK every year.