Damp wall | rising damp

damp wall | rising dampDamp wall is one of the worst defects that can affect a house. Even in its milder toms it is unpleasant but a serious outbreak will first destroy the decorations, then in time attack the woodwork, and eventually strike at the fabric of the building; it will make the place dank and unhealthy. There are three types of damp, each with its own causes and cures. Rising damp, as its name suggests, is damp rising up into the structure from the ground. Penetrating damp, caused by rainwater (or occasionally by water from a plumbing mishap), enters through defects in the shell of the building. The third type of damp is condensation, which originates inside the house. It is not always easy to decide which type of damp your Home is suffering from. In extreme cases it wil1take an expert to give a correct diagnosis. However, there are some general pointers. For instance, if the damp occurs low down on the wall near floor level, you can suspect rising damp. In, say, a bathroom that is prone to severe condensation, the paint can be lifted away from the wall by damp near the skirting, which is a symptom of rising damp, but the cause could equally be condensation streaming down to the bottom of the wall. The effects of condensation can also appear misleadingly on many parts of the walls and ceiling, but this type of damp wall is usually easy to recognize. It occurs when most of the windows are closed (which reduces ventilation) and after water vapour has been released into the air by cooking, washing clothes, or bathing.

roof insulation loft type | reduce heat lost

About 20 per cent of the heat lost from the average house goes through the roof. So while you are considering your roof you should ponder on how well your loft is insulated. To minimize heat loss, a thickness of 100mm or even 125 mm of insulation called roof insulation loft type in centrally heated homes is today more desirable than the mere 25 mm that was recommended previously. If you insulate your loft or top up the insulation already there you should recover your outlay, by way of reduced fuel bills, in about a couple of years. Although it is an unpleasant task carried out in cramped conditions, doing it yourself will guarantee that the work has not been skimped. Roof insulation loft type is available either in the form of a blanket that is rolled out between the joists or a loose fill material, that you pour from a sack. Both types are equally effective, but in an odd shaped loft with lots of nooks and crannies, it can be quicker and easier to pour out a loose material than to fit blanket. lf you are starting from scratch use whichever you wish. When topping up, it is better to use the type you already have. Take care not to place any load (even a foot) on the ceiling while you are in the loft, or it might break through. It is a good idea to take a plank with you and stand on that. Opinions vary about the clothes you should wear. Some people believe that if you wear as little as possible, you can take a shower afterwards and quickly wash away all the scratchy fibres. Others say you should protect yourself with long sleeved shirts buttoned at the collar, trousers tucked into socks and sleeves into gloves.

roof insulation loft type, reduce heat lostIn any event, you should protect your hands with gloves, and wear a cap or something to cover your head. Roll out the blanket, making sure it is well tucked down at the eaves so that wind cannot blow underneath it. If you use loose fill, simply pour it into place. It is, however, surprisingly easy to misjudge the depth to which you have filled a gap, so make a gauge from a length of wood with a notch cut out of each end of the lower edge to form a T with a short stubby descender. The depth of this descender should equal the distance from the top of the joists to the required top of the insulation. Rest the cross piece of the T on top of the joists, and drag it along to spread the granules to the correct depth. A well roof insulation loft type is cold, so make sure the water pipes and tanks are well protected, either with lagging or, if the pipes are low enough, by laying the blanket over them and draping it on top of the tank. Leave the space under the tank clear, however, so that warmth can penetrate up to it from the rooms below, as a further aid to stop it from freezing. One problem with attic insulation is that it can make the loft so cold that condensation develops and soaks the insulation, rendering it ineffective. Most lofts have sufficient ventilation to stop this from happening. lf not, lay polythene under the insulation as a vapour barrier, or install ventilating grilles.

wood rot repair – dry rot treatment

How to wood rot repair? Keeping rot at bay is better than treating it once it already has a hold. Rot is caused by damp. Dry rot cannot form in timber containing less than 25 per cent moisture, and wet rot requires moisture content in the timber of between 50 and 60 per cent. To have dry rot treatment, therefore, make sure your house is dry. If you suspect damp to be present anywhere, treat it as described earlier. Keep the gutters and down pipes in good order, so that the walls of the house do not become saturated. Moreover, the fungi do not spread so easily when there is good ventilation. Check that air bricks and grilles are not blocked and keep the paintwork, especially that on outdoor timber, in good condition so that rainwater cannot penetrate it. Begin wood rot repair, getting rid of rot. Wet rot is the easiest to deal with. As soon as you remove the damp, it will die out. You are, however, left with the job of replacing all the damaged timber. If these are important structural members, then seek professional advice. Non-structural timbers, such as skirting, window frames, picture rails, door frames and floorboards can be replaced. Prod the surface of the timber with a sharp instrument to determine the extent of the rot. Cut out and bum all affected wood, and remove all dust, dirt and debris. Make sure the new timber you use is sound, thoroughly dry and well seasoned. Also treat it, and the nearby timber, brick and concrete areas with dry rot fluid, to prevent that developing.


dry rotDry rot is much more difficult to eradicate, and dealing with extensive attacks is beyond the scope of the average do-it-yourseIfer. A thorough knowledge of building techniques is required, as well as a full acquaintance with the behavior and symptoms of the fungus. Moreover, the disturbance caused can be tremendous and the house may be uninhabitable during the work. You can, perhaps, cope with small outbreaks yourseIf. As with wet rot, it is essential to remove the conditions that cause the fungus to develop in the first place; make sure the house is dry and well ventilated. To tackle the infestation, inspect your home minutely for evidence of the rot after wood rot repair. Wherever you see any sign of attack, consider that point as being the centre of a sphere with a radius of 900 mm (3 ft) and make a close examination in every direction within that area. If you find any sign of decay, carry on with the sphere principle, until eventually you get to the limits of the attack. Cut away affected timber to a point 900 mm (3 ft) beyond the visible limits of an attack. If this involves the structural timbers, seek expert advice. The timber you cut out should be taken out of the house and burned. If strands have penetrated plaster, it must all be hacked off, taken outside in plastic bags and sprayed with dry rot fluid, before being taken away. Clean the whole area of the wall behind the plaster with a wire brush to make sure no strands are left.


wood rot

wood rot

The debris from cleaning must also be taken outside in plastic bags and sprayed before disposal. Where masonry has been affected, drill holes into the wall and fill them with dry rot fluid. The holes should be 13mm in diameter, 150 mm deep, and at an angle of 45°. They should cover the contaminated area at 600 mm (2 ft) staggered intervals. Working from the top downwards, spray all brick, block concrete and earth surfaces until they are saturated, using a spray with a coarse nozzle. The precautions about clothing and a mask suggested in the section on woodworm should be observed. If the strands have gone through the brickwork, deal with both sides similarly. Two coats of dry rot fluid must be applied to timber around the decayed timbers that ‘have been cut away. The treatment should extend to a distance of 1500 mm (5 ft) from the last affected spot. Treat the new timber with a fungicidal wood preservative. Brush on liberal applications, and stand sawn ends in a pot of the liquid for a good five minutes. Allow the wall to dry out properly before re-plastering and decorating. As an extra precaution, you may apply zinc oxycholoride plaster before the wall plaster.


The whole essence of the treatment of dry rot is thoroughness.  Leave any of the strands behind, and it can go on spreading. So you must carry on looking for further signs of the attack, and be sure that you have removed every trace. It would be a pity to go to all that trouble, then find in a short while you are having to carry out the remedial dry rot treatment all over again. lt is because of this – in addition to the scale of the work involved – that perhaps the work should be left to the experts, even though the cost of doing so can be high.

what is dry rot – wet rot in wood rot

dry rotWhat is dry rot, wet rot in wood rot? An occasional splashing, or even dousing, does no harm to timber, provided that it IS allowed to dry out thoroughly. Timber that is continually and excessively moist, however, will eventually rot. Most people can recognize the signs of rotting wood. lt warps and the surface starts to break up. Press it and it feels soft and spongy. By itself, the moisture in the timber does not cause rot. Rot is caused instead by fungi that are encouraged to grow in the dampness. A house that is well maintained, free from damp and well ventilated will not harbour rot. Rot is usually classified into two types; wet rot and dry rot. Do not be misled by the name of the latter; it too is caused by damp. It gets it name because it reduces the timber it attacks to a dry powdery surface.


wet rotWet rot is much more common than dry rot, but fortunately is easier to cure. Both are serious conditions much more so than woodworm. They can destroy the timbers of your home, reducing it to a dangerous, unhealthy and unsightly condition. Identifying rot is not difficult. Dry rot causes a musty smell and a lot or rust-red dust. The dust is, in fact, spores from a fungus. In advanced cases, deep cracks will break up the surface of the wood into cubes, some of them quite large. The surface of badly affected timber will be covered by a web of matted fungus. This web grows rapidly in humid conditions and generally looks like cotton wool. If it comes into contact with drier air, or is exposed to light, bright yellow patches appear. When the fungus is growing in damp conditions, globules of water-like drops are formed.


The fungus also produces a thin, pancake-like fruit. The centre is ridged and rust red in colour, but the edges are white. The wood darkens in colour, is powdery when rubbed between the fingers and loses its resinous smell. If you pick it up, it feels much lighter than it should. The most damaging parts of the fungus are the strands of the web. They spread, often unseen, and convey water to wood farther away that is dry and sound. Thus the condition spreads. Even if you remove defective wood, these strands could be left behind to continue spreading the fungus. As well as infecting the wood, they can pass through soft mortar and brickwork and find their way around stone and metal. The fungal strands of wet rot are never as thick as those of dry rot, and they do not spread with the same ease. They cannot, for instance, penetrate brickwork. Moreover, they are dark brown in colour and, when growing over the surface of wood or damp plaster. form a sort of fem shape. A thin veneer of surface wood may conceal a soft dark mass of rot underneath.

false ceiling

Pulling down an old defective ceiling is extremely messy and disruptive so, where the ceiling height permits, it might be better to erect a false ceiling just below the existing one. The way to do this is to fix a network of battens to the ceiling, with screws driven through them and the plaster into the joists. lf you decide on a plasterboard ceiling, the network should go both along and across the joists, to give the necessary fixing points, as detailed in the previous section. Finding the ceiling joists can be difficult, but in cases such as this – where there will be a good cover up you can make a series of test borings. Once you have determined the position of two joists you should easily locate the others, because usually the spacing between them is regular.


To get a good, level ceiling, all the battens should be at   the same height. Check that they are by placing a long, true batten, with a spirit level held against it, across them. To adjust the level, withdraw the battens fixing screws or drive them in further as necessary. Where the ceiling joists have twisted badly out of true, and the ceiling bows heavily in the middle, fix the battens at the perimeter of the room to the top of the wall, rather than the ceiling. The battens should have a cross section of about 50mm square, so long screws will be required a minimum of 100mm to get through batten, plaster and lath, and give a good, firm fixing, A false ceiling serves a useful function in a top-storey room, where there is no accessible attic space above. You can place insulation materials above the plasterboard, to make the house warmer, and so reduce heating bills.