Dampness can fall into the following categories;
- Rising Dampness
- Penetrating Dampness
- Tramatic Dampness
Rising damp is usually a sign of a damp patche appearing on an internal wall. This is often combined with damage to skirting board and decorations.
The result of this rising damp is structural damage to interior walls. It should also be noted that recent findings by the asthma foundation concluded that damp rooms can increase the risk of developing asthma. Rising damp occurs when ground water is allowed to rise vertically through walls by capillary action and is caused by the breakdown of, bridging of, or non existence of, a damp proof course (DPC). Thus the dampness is rising through the actual mortar beds rather than through the brickwork itself. This can become noticable from the outside as the mortar joints around the area will be of a darker colour than the rest of the brickwork.
If left unattended to, it will eventually cause rot to floor joists and other interior timbers that it comes into contact with, culminating in the development of wet rot or dry rot if conditions lack in ventilation..
Rising Damp can be casued be a number of issues, some are noted below;
- Blocked or defective rain water goods (guttering).
- High ground levels, new drive ways, paths or tarmac bridging the DPC.
- Defective pointing, porous brickwork, spauling bricks.
- Faulty or defective flashing on roofs or extensions.
- Cracked or Missing roof tiles or slates.
- Internal defects in cavity walls.
- Cracked or Defective window sills.
- Internal chimney defects- where a fireplace has been blocked in.
Windows start to steam up when the climate changes, resulting in condensation and mould growth. Not the most sightly thing to look at.
Condensation issues are very common and can sometimes be easily fixed with the fitting of the correct ventilators, providing an ambiant temperature in the property and allowing for air changes. The thermal properties of the property also have there part to play – a poorly insulated home is at a higher risk than a well insulated property of suffering from condensation issues.
In the colder months, condensation will occur somewhere in nearly every property which is not good news, but as noted above it can be easily managed.
Did you know……..?? “condensation issues are the largest single complaint received by landlords in both the public and private sectors, and generally a self-inflicted problem by the owner-occupier”.
Condensation is caused when warm, moist air meets a cold surface and the water vapour “condenses” out. The capacity of air to hold water is related to temperature; warm air holding more water than cold air. Air is saturated when it cannot hold any more water vapour at the existing temperature and therefore has a relative humidity (RH) of 100%. If the temperature of the air falls until saturation point occurs, the air is at a critical temperature or dew point where any further fall in temperature will result in water vapour being forced to condense out as liquid water.
The condensed water usualy apears as droplets on windows and other non- absorbent surfaces. This is surface condensation; it is fairly obvious and always occurs on the surfaces which are at or below the dew point of the air immediately adjacent.
Penetrating damp occurs when moisture seeps in from the external walls to the internal walls, it is usually caused by construction that has failed and occurs at a high level of the property.
- Blocked guttering, hoppers or down-pipes. These will overflow when blocked and saturate the adjacent wall
- Unused chimneys that are capped or sealed, which has defective haunching will allow water to enter the chimney and saturate the building
- Where flashing on a building fails leaks will occur, this leak can lead to penetrating damp
- Valley gutters that are not lined appropriately and are not carried 200mm up the pitch roof on either side of the valley, under the slates or tiles can cause penetrating damp to a building if snow or ice accumulates in the valley
Cavity walls that have a bridge; caused by rubbish left in the cavity or mortar that has been left on wall ties or insulation batts during construction, can cause penetrating damp if the wall experiences driving rain. Water can cross the cavity to the internal wall and saturate the inner masonry leaf and then onto the inner plaster.
Tramatic dampness is the cause of a leaking pipe, drain, tank or radiator, as an example.
Water is soaked up by the building fabric like a sponge, with the size of the patch steadily increasing as more water is absorbed.
This type of dampness is not related to rainfall, temperature or any seasonal changes.
When an incidence such as a burst pipe occurs, it is very important to have the damage inspected by a damp surveyor as the building fabric may need to have an anti-fungal tratement applied to prevent any mold growth, which could turn into a more troublesome dampness.
The diagram below gives a snap shot image of where you could find each of the 4no types of dampness detailed above.
Should you have any concerns at all for your property, we will be able to arrange a fully qualified building surveyor to attend and carry out a full survey and provide a written report on the findings.
Please do not hesitate to contact us to arrange a convenient time to carry out your survey, and also for your conveniance, we offer appointment times in the evenings and weekends!