Nem ve Rutubet Yalıtımı / Humidity and Moisture Insulation

Controlling humidity with humidity and moisture insulation makes your home more energy efficient, less costly to heat and cool, more comfortable and prevents mold growth. For facility professionals evaluating building retrofits, new construction, or insulation, paying attention to humidity and moisture performance helps ensure effective, long-term thermal resistance. Since the area to be sealed from moisture and dampness will not be visible, any problems with degraded materials will not be apparent, although the impact on higher energy bills is very real.

Wet insulation is an ineffective insulation. Rigid foams with high humidity and moisture retention lose about half of their insulation R-values. Because insulation installed over low-grade building foundations and under concrete slabs is often exposed to moist soil, it is crucial to choose an insulation with minimal long-term moisture retention and fast drying capability.

One challenge in choosing insulation is eliminating competing claims from insulation manufacturers. Manufacturers of extruded polystyrene (XPS) and expanded polystyrene (EPS) common under grade insulation, both claim their products are superior to moisture. Each is justified in its own way, but that depends on whether it’s looking at abstract, standardized tests or performance in real installed conditions.

How does this test represent reality? The truth is that it doesn’t reflect real-world conditions for two reasons:

  1. Unless your building is in a lake or river, or is subject to heavy flooding, the insulation will not be completely submerged.
  2. It does not take into account how much an insulation dries or dries out between periods of exposure to moisture.

XPS and EPS – Thermal Insulation Foams

EPS Polistiren / EPS PolystyreneXPS Polistiren / XPS Polystyrene

All marketing campaigns are built around this test, but when it comes to what actually happens in your building, one has to look at actual exposure during onsite tests. Studies of insulation exposure in real field conditions show that EPS outperforms XPS by a large margin because EPS dries much faster than XPS.

In a test; The moisture content of EPS and XPS embedded side-by-side for 15 years on a building foundation was evaluated. At the time the insulations were removed, EPS was four times drier than XPS. EPS contained only 4.8% moisture by volume compared to 18.9% moisture content for XPS. After a 30-day drying period, EPS dried to only 0.7% moisture by volume, while XPS still contained 15.7% moisture.

Insulation manufacturers are aware of how their products will perform over the years. Evidence of this is seen in the limitations stated in the warranties they offer. This is why XPS manufacturers usually only guarantee 90% of the insulating R-value of products during service, while most EPS manufacturers guarantee 100% of the R-value. Some XPS manufacturers will also void warranties in the event of pond or water immersion, as opposed to emphasizing the 24-hour full immersion test.