In essence, dampness in all its forms is the presence of excess moisture. Black mould growth on walls, furniture and even clothing; delaminated wallpaper and paintwork; rotten timbers; staining; musty smells. All are outward signs of a property that is damp.
As well as the damage it can cause to buildings, living in a damp environment can also give rise to health issues over time such as: respiratory conditions, allergies, skin and eye infections.
Condensation
Condensation is the most common type of damp. It can occur in several ways, often as surface condensation which, if left untreated can cause damage to plasterwork, paint and wood timbers; typically, window frames.
Condensation forms when the gaseous water vapour within warm, moist air meets a colder surface. Cold air cannot hold the same volume of water as warm air, and so, when the vapour meets its “dew point” droplets form. It’s why we see condensation form on mirrors, walls and windows in rooms such as kitchens and bathrooms when we cook, run taps to wash up, and when we bathe or shower.
Other activities such as drying our damp clothes on radiators will increase levels of warm moisture in the air within our homes. And the same process takes place even when we sleep; how many times have we woken after a cold night to find our bedroom windows covered in condensation? The vapour from our breath and the water we’ve excreted through perspiration increase the level of warm, moist air circulating around the home – when it hits the colder glass, water droplets will form.
Evidence of condensation can also be found, typically, in the corners of rooms, inside wardrobes and behind furniture, where cold spots are more likely and the air in these areas tends to stagnate.
It makes sense then that condensation peaks during the autumn and winter months when the contrast between the cold outside temperature and the warmth of our heated homes is at its greatest. Condensation levels will be further elevated when we decrease the flow of ventilation throughout our homes by routinely keeping our doors and windows closed.
Another type of condensation is interstitial condensation. The same gaseous water vapour we’ve already talked about, reaches its “dew point” and turns to water droplets, but does so within the structure of a building. This is an entirely natural phenomenon. When a building is able to “breathe” because its materials are permeable, water – whether in gas or droplet form – can move through its component structural parts by processes of diffusion or evaporation.
But when water is formed as interstitial condensation within a building’s structure and then trapped, damage attributable to damp can occur. Alterations to buildings, possibly with the use of impervious materials that are incompatible with the methods and materials used in properties’ original construction, along with their location, individual ground conditions and environmental surroundings can all contribute to the causes of interstitial condensation.
Evidence of the presence of interstitial condensation can appear on the surface of interior walls within the home. But often by the time it shows up, damage has already occurred within the structure. Corroded wall ties and rotten timbers are other examples of the types of damage that can go undetected until plaster and other backing render materials are hacked off to, first, facilitate essential drying out, before then deciding what remedial course of action needs to be taken.
How to reduce condensation?
The fact is that water vapour is everywhere and all around us. But there are several simple steps we can all take to reduce condensation levels in our homes. They cost nothing more than mindful changes in everyday behaviours, such as:
- Keeping windows open year-round to allow for increased airflow and fresh air exchange
- Keeping lids on pans while cooking and doors closed/windows open while washing up, bathing & showering
- Avoiding drying clothes on radiators. Running tumble dryer vents so they discharge outside the home
- Avoiding the use of gas fires/heaters
- Leaving a gap between furniture and walls, and airing cupboards and wardrobes periodically to allow for increased airflow
Other steps that can be taken with some additional expense are:
- Heating the home constantly during the colder months – budget permitting. Rather than setting the heating system to switch on/off on a timer, the alternative of switching the thermostat to the lowest possible setting but keeping it on constantly minimises sharp temperature fluctuations between cold and warm.
- Installing humidity sensing extractor fans, particularly in rooms where increased humidity is inevitable, such as bathrooms, kitchens and laundry rooms.
- Installing whole house dehumidifiers to increase controlled ventilation while reducing uncontrolled ventilation – otherwise known as draughts.
If you think that condensation dampness is causing damage, contact us today to arrange an appointment for an investigative survey as the first step towards restoring dryness and watertightness to your home.
Penetrating damp
Penetrating damp takes place, as its name implies, when water manages to ingress into a home. This can happen because the property isn’t watertight. There might be cracked render, mortar joints, faulty flashing around chimneys, dormers, or broken/displaced roof tiles. There might be defects in gutters/rainwater goods so that water isn’t adequately carried away from a property and, instead, it discharges onto and soaks through walls over a prolonged period.
Penetrating damp can also be the consequence of wind driven rain combined with inadequate cavity wall insulation in certain exposed walls. It might also occur because external ground levels are higher than the internal floors levels of a home, or fixed pipes serving the property are leaking.
Of course, the first step will be to identify and arrest the source of the water ingress. Beyond that, we can offer advice and remedial solutions. Contact us today to arrange an appointment for an investigative survey as the first step towards restoring dryness and watertightness to your home.
Rising damp
Rising damp occurs more rarely when moisture from the ground is able to move upwards through building materials, by a process of capillary action. After all, water is all around us. It is in the ground on which our properties are built. Rising ground levels, damage to existing drainage systems, along with construction and alterations using modern building materials like concrete without sufficient consideration being given to the corresponding impact on ground moisture levels, can all contribute to moisture penetration and subsequent damage to a building.
Damp Proof Courses (DPCs) were introduced into property building as a means of creating a barrier for rising damp in 1875. Materials changed through the years, taking in Bitumen felt materials from the 1920s all the way through to the plastic versions seen today. Their effectiveness is dependent upon their correct installation.
With rising damp, damage and decay can occur over time to building materials along with unsightly degradation to internal finishes within the property. Signs that might be indicative of rising damp are: delaminated wallpaper and paintwork; damaged/rotten skirting boards & timbers; staining; musty smells; and white tidemarks.
Tidemarks tend to be a sign of longer-term issues with water penetration from the ground up, where moisture has previously dissolved salts present in the building materials before evaporating to leave behind a fine white dusting, or, in certain circumstances, larger crystals. Surface damage can be caused to brickwork and masonry where the faces of individual bricks can flake, crumble, or blow. Deeper fractures that can compromise the integrity of the building materials can occur consequent upon the expansion of those salt crystals within their pores.
If you are experiencing any symptoms of dampness within your home, contact us today to arrange an appointment for an investigative survey as the first step towards restoring dryness and watertightness to your home.