In this section you will learn:
• how to recognize some common problems
• how to deal with these problems.
The main concern for most homeowners is electrical safety, which is tackled separately in a section of its own. The top nine concerns after this are:
In this section we will look at each of the above in turn.
What is rising damp?
The term rising damp is used to describe water that seems to be riling up through the ground, being soaked into brickwork and blockwork foundations. From there, it is sucked up by the masonry to levels that allow it to evaporate inside the property. This evaporation leaves salt deposits on the surface of the walls (see the section on efflorescence in Section 05) and/or mould on the plaster. Rising damp is often wrongly diagnosed when no real investigation has been carried out. The reality is that genuine rising damp is a rare occurrence. If there is rising damp, in all but the most extreme cases it is extremely rare that it will reach more than 1.2 m above floor level. It is at this point that gravity takes over from the capillary action which makes the water rise (capillary action or capillarity is the rise or fall of a liquid in a tube or other confined space, such as the very fine air pockets and cracks in masonry and mortar). The narrower the passage, the higher the liquid rises. Some fissures in masonry and mortar are indeed very small, but most are too large for capillary action to take place and it is overcome by the force of gravity pulling the liquid down again.
Dealing with rising damp
In Section 04, on foundations, you will read about damp proof courses and damp proof membranes. These are installed to stop moisture rising to a level where it could potentially get inside your house. This being the case, and despite many scientists’ attempts to prove that rising damp is a myth, the fact remains that water does, quite often, manifest itself on walls and skirting boards.
Of course rising damp exists, but it is not as bad as is widely thought. The remedies for rising damp are, for the most part, expensive, so anyone suspecting that they have rising damp should make absolutely sure that this is the problem, rather than any number of other possibilities, before resorting to remedial work of this nature. It is no good, either, to apply damp proof paint over a damp spot on the wall. Covering it up is only dealing with the effects of the damp. You need to deal with the cause first, then the effect.
Many people think they have rising damp when they find damp patches on the inside of external walls. This is generally not the problem, however — there are many possible causes of damp within a building, and all of the areas listed below should be checked before embarking on the major project of injecting a damp proof course or tanking the walls. (Tanking is a construction technique of covering the affected walls of a building in a waterproof and water repellent rendering material.)
• Check for a damp proof course. In most houses you can see a thin black line around the perimeter of the property, in between two bricks at about 150 mm from the ground (see Fig. 4.6). If you do not have one at all, think seriously about getting one installed.
• If the damp is at floor level, check for evidence of old doorways being bricked up without a damp proof course having been inserted. Check every bit of masonry for defective mortar joints or, if the walls are rendered, for cracks. With older stonework, look for cracked and broken stones.
• Is your patio too high or running towards the property? No part of your garden, even paths, patios and decking, should be higher than 150 mm below the level of the damp proof course. Constant rain splashing up the wall from paths, patios and decks that are too high can cause damp spots.
• Look for white, salty deposits on the brickwork. This is called efflorescence, and is a sure sign that there is an excess of moisture within the structure. When the moisture evaporates from the wall, it leaves behind the salts it has extracted from the masonry and/or mortar. How is it getting in?
• Check above and around windows/doors for a bad seal; water can get in and trickle through joints to find a weak spot.
• Check all ground levels, paths, etc. close to the house. Are they at least 150 mm (6 in) below the damp proof course? If they are not, dig them back. If this is impossible, look at the section on land drainage in Section 04.
• Check roof tiles for damage. Water can get in and run down the roofing felt, collect in the bottom of the felt where it meets the external walls, and rot through the felt. This will allow water onto the top of the walls, which can then trickle down through masonry joints and come in through a weak spot.
• Check all gutters for leakage, blockages and overflow. A constantly damp wall will suck moisture in. Check the gullies where your washing machine, dishwasher, downstairs sinks and basins discharge. Also check your overflow pipes.
• Check any abutments to the wall and the joint it creates. If a garden wall butts up against a house wall, water can become trapped in the joint and soak through to the house masonry.
• Check for holes drilled in walls for hanging baskets, etc.
• Have your drains checked for broken or blocked pipes and manholes.
See Project 36 on unblocking toilets and drains.
• Check all lead or other flashings for correct sealing at the point where they are cut (chased) into the wall. Check also for adequate coverage to the surface and joint they are protecting.
• Check outside taps for leaks.
• Outside flues can sometimes cause condensation on the external wall they rise on; check the masonry in this area. (Make sure the boiler is turned off for this check.)
• Once you are absolutely sure the moisture is not getting in from the outside, check all internal pipe and waste connections to washing machines, sinks, basins, dishwashers and so on.
• Check all toilet waste pipes and cistern connections and look for condensation on the cold feed pipes to all taps and valves.
• Once you are sure these internal pipes and connections are not the cause either, condensation is the most likely cause of the problem (see the next section for more information about this).
Do not attempt to decorate by sealing these damp spots in the wall. Moisture must be allowed to evaporate and the cause of the damp must be found. Sealing moisture in will lead to larger, more expensive problems.
Damp will sometimes remove the adhesion between plaster and wall, leaving the area ‘hollow’. This is easily detected by simply tapping on the wall. A wall should make the same or a very similar sound throughout, but a hollow wall will sound totally different. It is better to remove the plaster from this section and re-plaster it once the source of the damp is dealt with.
Damp plasterboard will swell and lose its insulation and decorative qualities. This is also better replaced. Mould can be treated by many fungicidal solutions on the market today, and fungicidal protective paints are available for areas of high humidity. Kitchen and bathroom paints are generally oil-based eggshell, which will not allow the absorption of water.
Remember, buildings must breathe. There is natural water content in all building materials. If this is sealed in by a waterproof coat on the outside, and similar applications on the inside, it can turn to mould easily.
See Project 39 on blocking stains.
Causes of Condensation
Condensation is an extremely underestimated cause of damage to our homes. It is also one of the very last causes of damp to be diagnosed. It is responsible for rot in rafters, joists and window frames. It can cause mould and fungal growth on walls and ceilings. If not desk with, it can damage our health.
All air contains water vapor. The amount it contains depends on the temperature of the air. This ratio is called the relative humidity. Hot air is able to carry much more moisture than cold air. As the temperature of air rises, in broad terms, it expands and attracts a greater volume of vapor. At a given temperature, the air can carry no more moisture until it is warmed up — this is called the dew point, at which the air is saturated. If the temperature drops while the air is saturated, the vapor is released.
• If this happens near the ground, to a small layer of air, dew or frost will be formed; if a larger amount of air is involved, mist or fog will arise.
• If this happens to air that is rising in the atmosphere and expanding, clouds will form.
• If it happens in the home, it’s called condensation!
As soon as warm air, containing vapor, hits a cooler surface, it will condense. This is most obvious on windows, cold water pipes in warm rooms and wall tiles, but it is happening on the walls and ceilings a lot of the time. It might be thought that if a house is insulated and warmed thoroughly then this should not happen, but it will. The air temperature will rise until it finds a cooler surface, unless we let out the warm air and let in some cooler air.
Ventilation is the answer to condensation. There are many ways to deal with the symptoms or effects of condensation, such as dehumidifiers, but only one way to deal properly with the cause — ensuring that the home is adequately ventilated.
Condensed moisture soaks into the walls and invites fungicidal spores, which develop into mould. This can cause breathing problems if not checked. Sometimes irreparable damage to walls and furniture can occur.
Dealing with condensation
• Open all windows at least once a day, even for five minutes. Change all of the air in the house.
• Wipe down walls and other surfaces regularly.
• Place proprietary absorbent strips or condensation tubs (available from most DIY shops) on windowsills and other problem areas.
• Place silica (a substance that absorbs moisture, available from chemists and some double-glazing stores) in strategic places around the home.
• Do not hang washing on radiators, or at least confine this to one room with the door closed. Afterwards, ventilate the room well.
Keep the kitchen door closed when cooking, and open the windows.
If security permits, leave top windows open, especially at night when the outside temperature drops and the indoor temperature rises as the heating kicks in.
Keep furniture a little further away from the walls so the air has a free flow around the room.
Do not fill cupboards to bursting point; again, allow the air to flow.
Make sure the insulation in the loft is not blocking the ventilation provided by the gap between the facia boards and the house wall or as in a lot of cases these days, purpose made vents. (See Section 06 for more about this.)
Install cavity wall insulation (if permissible through building regulations).
Have the heating thermostatically controlled wherever possible.
Ventilate tumble driers externally, or invest in a condensing tumble dryer.
Install extractor fans in the kitchen and bathroom. They are available with humidistat control.
Install trickle vents in windows. This is not a difficult operation. The vents come in two halves for inside and outside the window. Several holes are drilled through the top of the window head to allow the passage of air into and out of the room. Flaps are fitted so the vents can be closed, and insect grills keep all the creepy crawlies on the outside! Trickle vents can be bought from any double-glazing merchants.
A premium quality, low-odor, anti-mould coating can be used to protect against unsightly and unhygienic black mould, even when there is persistent condensation. This is achieved by combining modern paint technology with highly advanced, proven biocides. The anti-mould biocide is combined throughout the paint film, which is formulated to impart toughness, elasticity, water resistance and durability to the finish. Anti-mould emulsions can be bought from most good decorators’ merchants and the larger DIY stores.
A high quality coating is recommended for use on areas not subject to abrasion or washing. Typically this means ceilings, the underside of roofing sheets, ducting, steel building frames, pipework and inside cupboards. Anti-condensation coating inhibits condensation by absorbing moisture and improving insulation. It also contains a biocide for the sole purpose of protecting the paint from mould growth. This paint can be bought from decorators’ merchants and most stores.
Very little is known about woodworm by the general public, and it is a problem that is frequently encountered. A word of advice, then — if you live in an older house and haven’t done so already, go and check your rafters now. There are three types of woodworm in the UK: the common furniture beetle, the house longhorn beetle and the deathwatch beetle.
Symptoms and habitats
The furniture beetle is the most common of all woodworms. Damage by the furniture beetle is identifiable by a peppering of tiny holes in the surface of the wood. These are in fact emergence holes through which the adult beetle has left the timber after tunneling through it as a grub. This beetle attacks softwoods, leaving 1 - 2 mm exit holes in most softwood. It prefers damp rather than dry wood and the grubs will head for, and stay in, plywood for longer than any other timber.
Damp floorboards, damp loft timbers and old furniture where the polished finish has worn off (the furniture beetle prefers unfinished wood like old floorboards and loft rafters) are good targets for the beetle. It lays its eggs on the timber and the grubs do the burrowing and tunneling in the timber. With active woodworm there is a scattering of tiny dust piles on the timber. These are called ‘frass’.
Effects and implications
Structural weakening is rare with the furniture beetle except in timbers where the cross-section is small and there is a lot of damp. This occurs in older houses, for example, where the floor joists are near the ground and ventilation may have been blocked.
Treatment for this beetle can be bought from most DIY stores in the form of a spray or liquid preservative. Building societies will insist on a specialist company making repairs if structural timber has been affected.
House longhorn beetle
Symptoms and habitats
The house longhorn beetle is not common in the UK except in certain areas of north Surrey, where the coniferous areas and warmer summers suit its development. Strict building regulations have been introduced in these areas to stop the spread of this beetle, which is now quite rare in British buildings. It is principally found in roof timbers where it attacks the sapwood of exclusively softwood timbers.
fig. 2.3 an adult house longhorn beetle
Effects and implications
Attacks by house longhorn beetles often result in structural weakness of the roof timbers. The holes and tunnels of this beetle are significantly larger than those of the furniture beetle.
Treatment for this beetle can be bought from most DIY stores, as for the furniture beetle. Building societies will insist on a specialist company making repairs if structural timber has been affected.
Buildings in the area affected by the house longhorn beetle must have all new timbers treated, to comply with building regulations.
Symptoms and habitats
Deathwatch beetle attacks large hardwood timbers such as elm and oak. These timbers are usually found in the old churches, stately homes and other ancient buildings that are more common in southern and central England. Northern parts of Britain are not affected except where timbers have been imported.
The beetle, having started in these hardwoods may move across to neighboring softwoods in a kind of feeding frenzy! This beetle much prefers very damp conditions, particularly when there is some kind of fungal decay or ‘wet rot’ in the timbers. The beetle needs these conditions to develop rapidly.
Treatment, as with the other two, can be applied in the form of a paste, spray or paint-on preservative. It is recommended strongly that you call in a specialist if you think you have deathwatch beetle.
What is dry rot?
Named dry rot because of its apparent ability to grow in dry areas, this clever fungus has developed the ability to soak up moisture from timber, totally drying it out, and then develop strands which can travel across and through bricks and mortar to other timbers in unventilated conditions. It cannot feed on the masonry but carries the moisture with it in the strands to allow it to spread. Every property carries the risk of developing dry rot, but building regulations and the materials used in modern properties make it less likely to occur in these. In older properties, however, where kiln-dried timbers were not specified, roof tiles were generally clay and more porous, and most materials did not carry any British Standard specifications, wet timber and masonry could be found on all levels of a house when it was built.
Dealing with dry rot
DIY detection of dry rot is now considerably easier, and dry rot sensors can now be bought. These sensors are wooden dowels impregnated with a detector dye that are inserted into 8 mm holes in the ‘at risk’ area. The dye detects the presence of oxalic acid (present in all dry rot), turning the dowels yellow. DIY treatment of dry rot is possible, but most mortgage companies will insist on professional certification, together with insurance- backed guarantees. It therefore pays to contact a reputable damp proofing company to carry out repairs and treatment.
Why pipes burst
A burst pipe, especially when you are away from the property, is a homeowner’s nightmare. An unprotected water pipe will often freeze during the winter months. Frozen water expands quite dramatically and, if contained in a pipe where no expansion room is available, the pipe will split. This in itself is not the problem, however — the problem occurs when the ice thaws!
Dealing with a burst pipe
See our project (#32) on fixing a burst pipe.
Blowing light bulbs
Many people experience light bulbs blowing at regular intervals and fear that they have a dangerous electrical short circuit. This is not the case.
Myth versus fact
Myth: Regular blowing of light bulbs means you have a major wiring fault.
Fact: Regular blowing of light bulbs does not imply a major wiring fault. Any wiring fault in your circuit will be picked up by fuses and miniature circuit breakers (MCB5) long before it reaches the bulb.
Why light bulbs blow
There are a few reasons bulbs can blow.
• Cheap bulbs — the elements in cheap bulbs are very thin and any surge of power, however slight, simply breaks them. Always go for more expensive light bulbs; it’s cheaper in the long run.
• A loose connection in the lamp holder can also cause bulbs to blow. This is because the circuit is not completed as tightly as it could be and the electricity may have cause to ‘arc’, or jump, across the contact, rather than simply flow through it. When this happens it produces more heat in the fitting than is expected or catered for by the bulb, and the bulb can blow. The same can happen if the spring-loaded connection in the bulb holder is slightly loose. This will cause electricity to arc across the contact, causing too much heat and so blowing the bulb. This can often be diagnosed by looking at the contact on the bottom of the bulb to see if it is pitted — arcing electricity effectively melts the metal it is arcing onto (this is how arc welding works), so if the bulb contact is being subjected to arcing, tiny little indentations occur, called pitting.
• It is sometimes possible, if the live connection in your light switch is a little loose, for this to happen here also. Heat will be generated and it is possible, though very unlikely, for the bulb to blow as a result of this. When a bulb blows, 99 per cent of the time the circuit breaker for the lighting circuit will trip also. This makes the problem seem worse than it actually is. The reason for a blowing lamp tripping a MCB (miniature circuit breaker) is that the lamp element becomes thinner during its life until it breaks at the thinnest point; this point will melt just before failure. The resistance of the overheating element will momentarily be very low and a current surge is caused which is picked up by MCBs but not usually by fuses.
Dealing with blowing light bulbs
So, there are three things to look into if your bulbs keep blowing:
• the quality of your bulbs
• the wire connections inside your bulb holder, and whether the spring-loaded connectors are working properly inside the bulb holder
• the tightness of the connections in your switch. It is a good idea, wherever possible, to use dimmer switches. Dimmers that switch on at the lowest brightness are a big help in extending the life of a bulb, but a dimmer switch will reduce very slightly the maximum amount of light available.
Drilling through pipes and cables
This is a common problem for the DIY enthusiast, but it can be avoided. Having decided where you want to drill, check above and below for electrical sockets or water outlets. If there are any in the area, there is always a chance of hitting a pipe or cable. Always ascertain the type of wall you are drilling into. Pushing hard with a large drill on a plasterboard wall can send you straight through the plasterboard and into a pipe or cable in the void.
Pipe and cable detectors can be bought at all DIY stores for a few pounds and they are well worth the investment.
Radiator problems and maintenance
Radiator and heating problems fig. highly in the list of things homeowners are concerned about. The thought of spending either a few winter days without heat or a vast amount of money repairing a system motivates many DIY enthusiasts to find out as much as possible about their heating system. The following instructions are for the most common open-vented heating system only. See Section 08 to check your system before attempting any of the following.
Top of radiator cold, bottom hot
This is usually a result of air getting into the radiator and rising to the top, preventing any more hot water filling the radiator. The problem can be resolved by ‘bleeding off’ the air from the top of the radiator by opening the bleed nipple (a small square peg at the top of the radiator, usually protected by a round cast in the radiator body) and allowing the air to escape. Hold a cloth close to the bleed nipple — when water starts to come out the air should have gone. If your radiators need constant bleeding then too much air is entering the system and the problem is a bigger one that requires investigation by a central heating engineer.
Top of radiator hot, bottom cold
Rust and sludge has probably built up in the bottom of the radiator and this will displace any water, leaving the bottom of the radiator cold. Follow the instructions for draining down the system and then flush out the radiators. Proprietary sludge removers can be used to clean systems through. Theses are available from all plumbers’ merchants, but read the instructions before use.
Radiators hot downstairs, cold upstairs
This generally means that the feed and expansion tank in your loft has run dry, which can indicate a problem with the valve. This needs addressing quickly and a change of valve is usually in order. This is not a huge job and, as long as you have turned off the water, is well within the capabilities of a DIY enthusiast.
Radiators hot upstairs, cold downstairs
This may indicate a faulty central heating pump and should be checked by an engineer.
No radiators getting very warm
This indicates a build-up of rust and sludge. Follow the instructions for draining down the system.
Radiators warmer nearer the boiler
This shows that your system needs balancing. This can be done by turning the valves down on the radiators nearest the boilers to restrict the flow to them thus allowing those furthest away to receive a greater share of the hot water. See Section 07 to find out how the system works and to see this process in more detail.
Draining down the system
The thought of draining down a central heating system is quite daunting, but it is not a difficult process. Sometimes it is necessary to drain down a heating system to introduce an agent to clean it and flush it through, removing sludge, or simply to change a radiator. In all events it is necessary to turn off the boiler. Turn off the gas or electricity supply to the boiler or, in the case of a back boiler or solid fuel, make sure it is out.
In your loft you will have a tank called a feed and expansion tank. This is recognizable by a pipe coming in at the top, which is the expansion part of the equation. This allows the water to expand (in the form of steam) if it gets too hot. The steam can condense, via the pipe, into this tank.
The water is fed into this tank from the mains via a ball valve. This valve is the same as the one in your toilet cistern. When the water rises it lifts the ball-cock. The ball is attached to an arm, which closes the valve when it is lifted. When the tank is full of water, no more can get in because the valve is closed. When some water is drawn off, the ball drops, the valve opens and water rushes in to replace it. To ensure that no water comes in while you are draining the system, place a piece of timber across the tank, lift up the valve arm and tie it to the timber. This will close the valve and prevent it from opening when the water is drained from the system.
Now connect a hosepipe to the drain nozzle, which will be on or near one of the downstairs radiators, and run it outside to a suitable point. Make sure, especially in winter, that the water does not run onto the road or pavement where it could freeze and cause accidents. Open up the dram valve and let the water drain from the system.
The water will run faster if you open any bleed valves on the radiators, starting with the radiators at the top of the building. As the water level drops you can open the bleed valves in the downstairs radiators also. When no more water comes out of the hose you must check that the system has finished draining before you remove radiators or start work. There is a chance that some air has got into the system and locked the water from escaping. Go into the loft and fill the tank with about six inches of water by loosening the arm you have tied up. This should, in a few seconds, start running out of the hose. If it does not, you have an airlock and should connect the other end of the hose to the cold tap and send a short blast of water back into the radiator you are draining from. Make absolutely sure the hose is well attached to the radiator drain nozzle and close any open bleed valves before you turn on the tap.
Refilling the system
Close the drain valve on the radiator and all the bleed valves you have opened. Untie the piece of wood in the feed tank and let the water fill up the system via the tank. Wait until the tank stops filling and go downstairs to bleed the bottom-level radiators. Repeat with the upstairs radiators. This should ensure that your system is properly filled.
Double-check the work you have done to ensure you have retightened all nuts, etc., turn on your power supply and relight the boiler. As the water heats up, you may hear some knocking sounds as any air in the system expands. The radiators will probably need bleeding again once the system is fully heated.
Fire, carbon monoxide poisoning and gas leaks
It is essential that all homes are fitted with fire and smoke alarms and carbon monoxide detectors.
Wherever possible, alarms should be fitted to the mains with battery back up. Every year the Fire Service is called to over 600,000 fires, which result in over 800 deaths and over 17,000 injuries. An unbelievable 50,000 (140 per day!) of these happen in the home and kill nearly 500 people. Over 11,000 people are injured in the home. Many of these injuries and deaths could be prevented if an early warning system had been put in place.
There are three types of smoke alarm currently on the market: ionization, optical and combined. The optical type is often described as photo-electronic.
• Ionization: These are the cheapest from of detection and cost very little either to buy or run. They are very sensitive to small particles of smoke produced by flaming fires, such as chip-pan fires. They will detect this type of fire before the smoke gets too thick. They are marginally less sensitive to slow-burning and smoldering fires, which give off larger quantities of smoke before flaming occurs.
• Optical: These are more expensive but more effective at detecting larger particles of smoke produced by slow-burning fires, such as burning foam-filled upholstery and overheated wiring. They are marginally less sensitive to free-burning flaming fires.
• Combination: As the name suggests, these are a combination of both of the above and can also include an emergency escape light. These units are usually a little more expensive but give greater peace of mind.
The different types of detector look similar to each other and are powered by battery, mains or a combination of both. Some are inter-connectable, so a fire in one part of the home can set off the alarm in another. Some have additional functions, such as emergency lights.
Buying and fitting smoke alarms and ensuring that they are properly maintained could give you that extra few seconds in which to execute a safe escape. Plan an escape from your home in advance and talk about it with your family. If a fire occurs and you have to get out in the dark, make sure you have a system for letting others know you are safe, such as all meeting in the same place in the garden or other safe place.
Carbon monoxide poisoning
Carbon monoxide is produced as a result of the incomplete combustion of fossil fuels. This includes gas, oil, coal and wood, all used in the home. Carbon monoxide is poisonous to humans and is particularly dangerous as it is colorless, odorless and tasteless. Carbon monoxide detectors can be bought from all DIY stores and are an extremely worthwhile investment given the poisonous properties of this gas and the impossibility of detecting it any other way.
If one of your fossil fuel-burning appliances at home is not working properly there are telltale signs for you to watch out for, such as soot or other stains and discoloration at the joints of flues and gas water heaters. This indicates that the flue is blocked or partially blocked and the dangerous fuel residues are not escaping.
Natural gas is a very safe means of heating your home. If leaks occur they can usually be smelled quite easily, giving some warning that there is a problem, but fitting a detector for gas leaks can certainly do no harm. Gas detectors are not as widely available as other detectors but can be found, together with installation instructions, on the Internet.Prev. Next Top of page Home