Condensation and Surface Temperatures
[ad_1]
If all the other factors remain the same, any improvement in the thermal insulation of your house will result in higher surface temperatures and consequently reduce the risk of condensation.
Pitched roofs Installing (or adding) to the insulation on the loft floor is certainly one of the most effective ways of saving money on heating bills. This will avoid condensation on the underside of upper-floor ceilings but may dramatically increase the possibility of condensation in the loft space particularly if the loft hatch and holes down to the house are not well sealed and spaces are not left at the eaves.
Insulating materials such as mineral wool, preferably about 100mm thick, can be laid between the joists. The insulation must be laid evenly between the joists with no gaps and must be taken down to the eaves to cover the wall head, while ensuring that ventilation openings are not blocked.
As improving the insulation of the ceiling will make the roof space colder, the movement of moist air from the house into the roof space must be kept to a minimum. Gaps in the ceiling – around pipes, cables, and so on – must be sealed as well as possible. The roof (loft) hatch should also be sealed and fitted with a catch to prevent movement. As long as you have had no previous serious problems with condensation in your roof space, the above precautions should be sufficient. However, if condensation occurs, you will have to improve the ventilation in the roof space by providing ventilation openings at the caves if they are not already there. Or add roof tile and ridge ventilators and air bricks in gable end walls.
If you insulate your loft, you should also insulate the cold water cistern and all pipes.
Flat roofs (bitumen felt or metal covered)
Although improved insulation may be possible, how it should be done depends on the type of roof. Repair or renewal of existing roofs should be of the over-deck insulated type.
External walls
You can increase the insulation properties of a wall by apply¬ing extra insulation material to the inside or outside surface of the wall or within the wall itself. As a d-i-y task, fitting internal linings is the most practicable. Cavity wall insulation has to be left to specialist contractors (except when building a new house) and insulating the outside of wall involves a considerable number of alterations.
A lightweight lining built on to the inside of a masonry wall produces a surface which warms up and cools down considerably faster than the wall itself -so the temperature of the surface directly in contact with the air is more able to keep in step with the air temperature in the house. This will considerably reduce the risk of condensation if your house is intermittently heated – unoccupied during the day with little or no healing on followed by very large moisture and heat inputs during the early evening.
A plasterboard lining is generally sufficient to prevent surface condensation on a cavity wall but insulating plasterboard is preferable for a solid wall.
When you build on a lightweight wall lining you must provide a vapor cheek to restrict the flow of water vapor through the wall so that condensation within the wall is kept to the minimum. This can be achieved either by using a special vapor check board or by stapling a separate sheet of polythene to the timber battens holding the board to the wall.
You can also improve the condensation resistance of a cavity wall by sticking insulating material directly to the inside surface of the wall. The insulating material can be rolls of thin polystyrene which will warm the wall surface but will add very little to its insulation. A dis¬advantage of thin polystyrene is that it dents easily; more substantial wall insulating material will not only not dent but will add significantly to the insulation of the wall while stopping condensation.
Cold bridges
These occur when the thermal insulation of small areas of a wall is considerably lower than the wall which surrounds them. Typical cold bridges are window lintels and solid columns forming part of a wall. Condensation prob¬lems on cold bridges can seldom, if ever, be satisfactorily prevented by adjusting the heat input, ventilation or moisture production. Remedial treatment is generally necessary.
The easiest way to overcome a cold patch on a wall is to stick insulation over it. Choose a type of insulation which is not permeable to water vapor. It may be possible to hide the insulation in the plaster finish. However, in many instances, techniques similar to those described for improving wall insulation will have to be used to obtain a pleasant and satisfactory wall finish.
Windows Condensation on the glass of single-glazed windows can be overcome by installing double glazing. However, in many eases condensation will still occur on metal window frames. Double glazing at present is barely cost effective as far as fuel saving is concerned, but when window frames have to be replaced then double-glazed windows should be considered.
While double glazing will almost certainly reduce the condensation level on the glazing, it may well increase condensation elsewhere. The reason for this is simple: modern double-glazing systems especially high-performance replacement windows are an extremely effective method of draught proofing and, when used to replace a leaky single-glazed window, may simply move the condensation problem somewhere else, typically a cold outside wall.
[ad_2]
Source by Tauqeer Ul Hassan