Insulation of the floor in a wooden house: simple tips
Hello.
The issue of warming the floor of the first floor in a wooden house. The floor consists of:
- wooden logs;
- black floor (edged board);
- isospan;
- mineral wool insulation;
- vapor barrier technofol 0.3;
- grooved board.
I want to clarify whether it is possible to make insulation in this order?
Svetlana
Expert Answer
Hello Svetlana!
You touched on a very interesting and topical topic. In turn, I would like to ask you a counter question. If you form the floor of a wooden house in the exact order that you specified, then how will ventilation gaps between the materials of the heat insulation pie be created? The same technofol does not let steam pass at all, which means that the sheet pile laid on it from below will be wet. No matter how much you infuse it with an antiseptic before laying, it will still be affected by the fungus and rot.
For this reason, it is necessary, first of all, to evaluate the total thickness of the insulation and relate it to the cross section of the log. If necessary, a counter beam can be nailed from below to the logs and a slab (unedged board) can be fixed on it - the cracks here will not hinder. After this, wind protection (waterproofing membrane) should be laid and thermal insulation should be placed in the space between the logs. From above, the insulation layer must be covered with a vapor barrier membrane. But it is better to abandon the use of technofol (or use it instead of the bottom layer of waterproofing) - from above it will interfere with the ventilation of mineral wool. Before laying the tongue-and-groove board, make sure that there is a clearance of at least 2 cm between the final floor and the vapor barrier. You can raise the level with the help of counter-rails, which are stuffed along the lags. After that, you can finally fix the finish materials.
If it is not possible to work from below, then from the sides to the logs you can attach a beam and lay the rough floor on top of it. In this case, to compensate for the height of the lag, you have to choose a counterrail of increased thickness. And the last thing I would like to recall: be sure to calculate the thickness of the insulation based on heat loss. Remember that due to a too thin layer, the dew point will shift to the lower surface of the insulation. And since you plan to use mineral wool, when wet it will not only lose most of its heat-insulating ability, but will also cause rotting and damage to wooden structural elements.
