There are two options for insulating a bath - outside and inside. I prefer insulation from the inside as it seems more labor intensive to me. This "operation" includes three stages: first, the walls are processed, then the ceiling and floor.
When insulating a bath, it is important to take into account the high level of humidity - no matter how reliable the thermal insulation is, it must be covered with a layer of vapor barrier. If water begins to accumulate in the insulation, it will not last long.
Walls
As a heater, I chose basalt wool - a high-quality and affordable material that can be bought at any hardware store. I don't want to use polystyrene and other synthetics due to the fact that it does not breathe at all and is highly flammable. When insulating the walls, I acted in this order:
- on the surface of the walls I hung a crate from a dry wooden bar;
- between the battens of the lathing covered with a sheet of fiberglass;
- a layer of basalt wool was laid on top of the fiberglass;
- placed a layer of aluminum foil on the thermal insulation layer (as a vapor barrier);
- in the end, he mounted a decorative finish from a wooden lining.
Ceiling
Ceiling insulation is very similar to wall insulation with one difference - I did not use foil in the washing room and dressing room. Instead, polyethylene is well suited - it is cheaper and does an excellent job.
Also, the vapor barrier layer must be separated from the decorative cladding layer - I leave a gap of 1-2 centimeters. This hole allows air to circulate and dries the sheathing material.
Floor
When preparing a bath for winter, many summer residents make a mistake and forget about the floor. But the floor is one of the main reasons for the "leakage" of heat - along with walls and ceilings. I insulate the floors according to the following scheme:
- I pour a concrete screed on the earthen floor (before that, it must be leveled and tamped);
- I put a dense layer of polyethylene after the heavy hardens - it serves as a layer of waterproofing;
- I put sheets of polystyrene foam (as insulation);
- I place another layer of polyethylene on top of the insulation;
- pour the final layer of concrete screed.
The floors in the bathhouse are constantly in contact with water, so one layer of waterproofing is not enough. How long the structure will last depends on the quality of the foam. If drops enter the insulation through the screed, it will not be able to provide sufficient protection.
Materials
Over the years, I have tried different heaters for the bathhouse and eventually settled on basalt fiber. I must say right away that this is not the cheapest solution, but the most profitable in the long term. If you don't want to be stingy, who pays twice, I advise you to take a closer look at basalt. Among its advantages, I can note:
- non-flammable (which is especially important for the steam room);
- resistance to moisture and deformation;
- excellent sound absorption;
- high-quality thermal insulation.
When laying, basalt fibers are cut into pieces and placed on the lathing. The ability to shape them into any shape adds to their versatility. If basalt fibers are installed correctly, they can last for several decades.