The Facts About Damp, Mould and condensation A short informative guide to common causes of dampnesd within buildings, the problems associated with it & the solutions available to you. Freephone 0800 612 8891 Mobile 07921 889261 www.definitivedampsolutions.co.uk
33 Westdale Road, Jacksdale, Nottinghamshire, NG16 5JG T 0800 612 8891 E sales@definitivedampsolutions.co.uk This guide has been written to highlight damp and other problems with moisture within the home. It also contains practical advice on tackling the problems of moisture build up and explains where and how this hazardous situation can occur. Every effort has been made to ensure that the information contained in this book is accurate, however due to circumstances beyond our control the author cannot be held responsible for any injuries, losses or any other damages which may result from use of this information. www.definitivedampsolutions.co.uk Definitive Damp Solutions Ltd 2013
Contents 1. Overview of damp 2. Problems with condensation 3. The need for adequate ventilation 4. Insulation basics and heating 5. Mould and how to deal with it
The facts about Damp, Mould & Condensation The cause of damp is often fairly obvious from the symptoms that the different forms of damp present; however, this is not always the case. Usually damp is identified due to the musty smell, mould or damp patches that appear inside the home. The most common form within homes in this country is condensation. Water vapour is present everywhere and can be highly invasive Lack of Breathability and a build up of water vapour in our buildings not only cause rot, damp and structural failure, it is also a major contributor to sick building syndrome. It has also been heavily linked to the rise of asthma and allergies in this country. Permeability is one of the most widely needed measurements on everything we use in building today, from roofing to walls and floors. Water Vapour Permeability Quite simply is the way that water moves through a structure. In the context of breathability, vapour permeability is the rate of passage of water vapour through solid materials. Water molecules as vapour (which is gas below boiling point) will pass through a variety of materials at different rates according to the pore size and thickness of the material. The issue really is the rate at which they do this. The following section gives an overview of the types of problems with damp and moisture within the home. It also gives recommendations and solutions to cure certain situations. Rising Damp In a nutshell this is water soaked up from the ground by capillary action and is only a problem when a building has no Damp Proof Course (D.P.C), very common in older buildings(pre 1930), or if the D.P.C has been bridged or damaged. Examples of bridging would be rendering over the D.P.C and taking a coating to the floor or raising the level of the ground around the walls and taking it up to or over the level of the D.P.C. The usual evidence of damp of this kind is a tide mark on the walls that show how high the moisture has risen. This is usually due to the salts being deposited in the bricks face as the moisture evaporates. It usually leaves a musty smell, Internal decoration can be stained and damaged; internal plaster may become crumbly and fall from the wall. Rising damp only rises about 1m above ground level due to gravity and the capillary forces.
The solution to rising damp - is usually to inject a chemical D.P.C. This may need to be done to various areas and can ocassionally need to be done internally as well as externally. After this has been carried out any remedial work to the interior can be done. If re-plastering is required a water proof additive would need to be added. A lot of companies will insist on the replacement of plaster to justify charging you extra money. This type of work carries varying guarantee periods but usually between 20 30 years. Penetrating Damp Water penetrating through the roof or walls. This is where water leaks into a building through a fault such as around a chimney stack or windows. Examples of this could also be missing roof tiles or lack of mortar between brick courses. Also look for leaking or missing drainpipes as these can lead to water soaking all the way through the wall. Damp occurs when a fault in the building s structure lets water in from the outside. If the external faces of the bricks have lost their integrity they then begin to absorb too much water as a liquid, this then causes a blockage to water vapour as it cannot pass through a liquid. This type of problem is often made apparent internally by the appearance of isolated damp patches. How do I stop penetrating damp? In some cases these internal patches will be simply rectified by making appropriate external repairs, for example re-pointing. However if this problem is more widespread internally this will lead to higher moisture content in plaster work, decorative finishes and the home in general. This will then need a more permanent solution. To stop this continuing to be a problem, some form of external weather protection, such as a specialist render system or resin based clear coating would need to be applied. Condensation Usually more noticeable in winter, because the building is cold and because windows are opened less so moist air cannot escape. When warm moist air produced by ordinary household activities hits a cold surface it condenses into water droplets i.e. an outside wall or window condensation occurs. Unless this moist air can escape through an open window or extractor fan, it will always stay in your home moving around until it finds a cold spot where it will form condensation. If this happens regularly then mould may start to grow. The temperature of a room determines how much water vapour the air within that room can hold. Keep doors closed when these rooms are in use. This stops moisture reaching other rooms, especially bedrooms which are colder. This moisture can damage clothing, furnishings and decoration. It can commonly be found near or on windows and leaves a musty smell. Unlike rising damp this type does not leave a tide mark. Lack of ventilation in the house can make this problem worse and can be made even worse by too much draught proofing. Raising the temperature in a room suddenly can put warm air in contact with cold surfaces increasing the chances of water vapour condensing, again, if this happens regularly mould will form. This problem is home made. Household activities like Cooking, Breathing, Bathing or drying clothes to name a few all are a major source of water vapour within the home.
How can you control condensation? A balance of good insulation, constant background heating, moisture control and ventilation. The following steps may reduce or possibly eliminate condensation in your home. Preventing condensation Try not to dry clothes in your home. If this is not practical, keep the door of the room where clothes are drying closed. Open the windows, as this will allow the moisture from the clothes to escape outside and will prevent it circulating around your home. If you use a tumble drier make sure it is vented to the outside or use a condensing dryer. When cooking the kitchen should be ventilated. Use an extractor fan if you have one or open a window. Keep the kitchen door closed. Cover boiling pans with pan lids this will save money on your fuel bills as well reducing moisture. When bathing or washing keep the bathroom door closed. Switch on extractor fan on if you have one. If there is a lot of water vapour in the atmosphere leave the fan on or open a window to disperse the moist air when you have finished bathing. Keep furniture such as beds and wardrobes clear from the walls to let air circulate. Keep your house warm at a consistent temperature. This will cut down condensation as water does not condense in warm air. Background heating and ventilation will reduce condensation, especially in winter. Avoid using portable paraffin or bottled gas heaters. They give off a lot of moisture when they burn, as much of 1 litre of water for each litre of fuel burned, so open a window if you have to use one. Ventilation Ventilation in the home, if adequate, will allow moisture to escape to the outside. Modern living has led to a decrease in natural ventilation. We have over recent years installed double glazed windows and doors, introduced daily showers and sealed off open fireplaces. The average household in the UK can put as much as 15 litres of water into it s air on a daily basis! The simplest and cheapest form of ventilation is to leave a window open whenever possible. In housing built before 1875 they were often built with no D.P.C. and very little protection externally from penetrating damp. You would think that these two factors combined with the lack of a cavity would give some cause for concern? No, the general principles of older construction were that although this damp could rise or penetrate, and the way in which these properties were ventilated combined with draughty single glazed wooden windows that this damp would evaporate externally without any real damage. This ventilation also prevented any condensation developing. Use an extractor fan in the bathroom when you bath or shower if you have one. Open windows slightly after bathing to get rid of the moisture. Use extractor fan in the kitchen or open a window when cooking. If you have trickle vents above windows keep them open all the time. Never block up any air vents or air bricks and if you haven t got any look into having some fitted. Heat exchange units are also a good way to encourage air circulation without causing draughts. These units mechanically draw fresh air in from the outside whilst drawing stale air out of the room. This warmer stale air is used to heat the incoming fresh air.
Dehumidifiers - One popular solution to damp and condensation problems is a dehumidifier. These come in various shapes and sizes ranging from small units which will keep a closet or wardrobe dry to large units which are capable of drying out anything from a room to a whole house. Most models have a level switch which will turn the dehumidifier off and sound an alarm when the tank is full. Also popular for small areas are chemical dehumidifiers. These contain a moisture absorbing chemical which soaks up damp from the air. Some types can be re-used by heating in an oven or microwave but always check the manufacturers instructions. Insulation condensation occurs on cold spots, so if you can warm up the cold spots you will help control condensation. Insulating your loft, external walls and draught proofing doors and windows should reduce the amount of cold spots and make your house cheaper to heat. Insulated well, they will remain warmer for longer, reducing the risk of water vapour condensation and therefore reducing the conditions that are ideal for mould growth. Heating try to avoid having cold areas within the home. It is better to heat the whole house on a lower temperature than it is to heat one room on a very high temperature. When you get condensation and mould forming, it is often not the room that you are creating the moisture in e.g. kitchen or bathroom but in a room that you don t often use e.g. spare bedroom. This is probably because this room is not usually heated. Try heating all the rooms regularly. Make sure you are using the heating system and its controls efficiently as this will also save you money. Consistent heating will eventually allow warmth to penetrate walls and ceilings which helps to remove the water vapour. During the cooler months always try to keep the inside temperature at least 5º C higher than the temperature outside. Moisture Reducing the amount of moisture in your home will cut down the amount of condensation. Listed below are the biggest sources of moisture in the home: Drying clothes in an un-vented tumble drier Cooking by gas for 3 hours Having a bath Washing clothes 10 Pints 3 Pints 2 Pints 1 Pint Mould Is a type of fungi that can grow in a range of areas within the home but only when there is damp present. Although there are many different types of mould they all thrive on high humidity and when growing gives off particles that can cause allergic reactions. If humidity drops suddenly these particles can be in their millions and can cause sneezes. Mould growth within buildings has been heavily linked with asthma and other respiratory conditions especially in children or susceptible adults.
This usually appears on cold outside walls and surfaces where air does not circulate well. It is usually confined to areas where ventilation and air circulation are very poor such as corners or behind furniture; it is also common in very cold areas such as around window openings. Mould spores will only grow in clean water as opposed to the contaminated water from rising or penetrating damp. How can I get rid of Mould? Following the advice will help to reduce condensation. You may even completely remove it all together and mould should not re-appear. If condensation does occur, wipe up any moisture with a dry cloth. If mould has managed to grow then tackle it with the following steps: Mould usually can be removed with a diluted solution of bleach, following carefully the manufacturer s safety advice. Always test a small discreet area first before applying it to the whole area. After applying to the affected surface leave it for about 20 minutes then sponge with water. In more severe cases, to kill and remove mould, wipe down walls and window frames with a fungicidal wash. Follow manufacturer s instructions carefully. Dry clean any clothes or affected material and shampoo any carpets. Disturbing mould spores by brushing or vacuuming may increase the risk of respiratory problems. Mould eradications kits offer the best way to completely remove mould. Kits are available through our office. After treatment, re-decorate using a good quality fungicidal paint to help prevent reoccurrence. The use of harder and less permeable cement based plasters or renders and the introduction of double glazed windows can create an internal environment where there is little air movement or ventilation. When coupled with little or no background heating this will result in areas of condensation and can also prevent the damp in external walls from drying out between periods of wet weather. For any further help or advice with damp related issues call our free advice line or contact us in the following ways: Advice line: 0800 612 8891 email: enquiries@definitivedampsolutions.co.uk Definitive Damp Solutions Ltd, 33 Westdale Road, Jacksdale, Nottinghamshire, NG16 5JG