So you now have new windows installed. New windows have, compared to the old windows – good insulation due to the effect of a higher surface temperature (about 18 degrees) than the old windows (about 10 degrees). It is because of this warm cozy space, you can turn down anything and save the heating (for example, 21 degrees), and heating costs.
Warning: Cooler air absorbs less water, the humidity rises in the room at a certain rate. The dew point temperature increases as a result, the surface temperature of the wall falls to about 13.5 degrees in the corners at less than 10 degrees. There, the dew point is now slightly below. The result is in all probability, there is mould on the walls.
The 18 degree warm windows now stay dry, the condensation forms on the wallpaper as moisture that you cannot see. And you cannot wipe it. It is absorbed into the wall and the wallpaper paste becomes an optimal mould breeding ground. You can ventilate however it is probably too late. Although the air is at times a bit dry, but the wall surfaces are not warmer. On the contrary. Cool on to say it can get mouldy even more.
Now that the room is ventilated properly, and although reduced for a short time the humidity and thus reduces the risk of mould briefly, but shortly after closing the window, the humidity rises again and condensation water can precipitate on the cold walls. Continuous ventilation would now be fatal. For more info click here.
Third: Some new windows include a facade insulation. If you include new windows in old walls, then one must also look at the facade very accurate and insulate them. Because with a facade insulation raises to the surface temperature (inside) of the wall up to 19 degrees and there can be no more condensation – and no mould. Thus saving the existing paint work or making it easier to repaint when you need to.
Conclusion: If you include new windows and then in most cased you will be free from mouldy walls. This will not only preserve the existing paint job on the walls .
As part of a facade insulation not all are insulated from cost reasons, the window reveals. A little later there is mildew on the inside of the non-insulated window frames and we are angry. In our circle we tell now the following: “I have now insulated and mouldy walls.” We know that this is true, finally, we have experienced it myself. In reality, this statement is wrong. Because the walls mouldy only where they were not insulated. In this case, just the soffits were not insulated.
One of the most important energy-saving messages that you around the house, must including soffits and base, insulation, and building physics, if you want to do everything right. Finally, go so well in the thick of winter completely packed out.
Even so, another mistake is sometimes made. On the inside of an insulation between the insulation and the old facade, condensation could occur. How does it work? There is always warm, it is there always dry under normal circumstances. And even if there – as it was always possible – but some moisture should occur, this is not tragic, because polystyrene (Styrofoam) has water vapor diffusion resistance values, which are very similar to those of wood. Although there is virtually waterproof (extruded) polystyrene for insulation of exterior basement walls. On the facade but is the vapour permeable (“breathable”) material is used.