Moisture Dry-Out Capability of Steel-Faced Mineral Wool Insulated Sandwich Panels

Abstract

Moisture dry-out from steel-faced insulated sandwich panels has previously received little attention from researchers. This paper reports the results from laboratory tests and dynamic heat, air, and moisture transport simulations of the moisture dry-out capabilities of a steel-faced sandwich panel with a mineral wool core. Three test walls (TWs) with dimensions of 1.2 m × 0.4 m × 0.23 m were put above water containers to examine the moisture transport through the TWs. A calibrated simulation model was used to investigate the hygrothermal regime of a sandwich panel wall enclosure with different initial moisture contents and panel joint tightening tapes. The moisture dry-out capacity of the studied sandwich panels is limited (up to 2 g/day through a 30-mm-wide and 3-m-long vertical joint without tapes). When the vertical joint was covered with a vapour-permeable tape, the moisture dry-out was reduced to 1 g/day and when the joint was covered with a vapour-retarding tape, the dry-out was negligible. A very small amount of rain would be enough to raise the moisture content to water vapour saturation levels inside the sandwich wall, had the rain ingressed the enclosure. The calculated time of wetness (TOW) on the internal surface of the outer steel sheet stayed indefinitely at about 5500 h/year when vapour-retarding tapes were used and the initial relative humidity (RH) was over 80%. TOW stabilised to about 2000 h/year when a vapour-permeable tape was used regardless of the initial humidity inside the panel. A vapour-permeable tape allowed moisture dry-out but also vapour diffusion from the outside environment. To minimise the risk of moisture damage, avoiding moisture ingress during construction time or due to accidents is necessary. Additionally, a knowledge-based method is recommended to manage moisture safety during the construction process.

Effect of Artificial Aging of Peel Adhesion of Self-Adhesive Tapes on Different Construction Surfaces

“…Several studies have been carried out to investigate the maintenance/loss of sealing using adhesive tapes. It has been established that the hygrothermal behaviour of steel-faced insulated sandwich panels can be controlled using adhesive tapes [5,6]. The tape is seen as a viable solution when it is required to ensure the level of tightness of a wooden frame [7]; however, it is understood that the durability of adhesion is not sufficient to ensure the good tightness of the joint for a long period [8].…”

Impact of artificial ageing on the performance of acrylic self-adhesive tapes

“…Research [1] showed that after 8 months of outdoor aging, some of the exterior air barrier tapes, glued to the outer wall of the barrack hut from plywood panels, completely or largely peeled off from the glued surface, while others showed a change in color, bubbling, or other signs of degradation. A maintaining/losing the sealing purpose of self-adhesive tapes, as well as finding promising solutions to ensure the airtightness of the building are investigated mostly [2][3][4][5][6][7][8][9][10]. However, very few studies aim to investigate the aging of tapes and the factors influencing the deterioration of tapes' properties.…”

Moisture drying capacity of mineral wool insulated steel-faced sandwich panels by convection

“…This makes it possible to form a clearly defined area where air must move to dry the structure. As diffusion drying from a steel-faced mineral wool insulated sandwich panel is limited [9], convection drying is a method to increase the efficiency of moisture dry-out. However, there is still relatively limited research on this field.…”

“…Moisture dry-out at stable temperature conditions (Figure1). Diffusive drying 2020 refers to a previous research on vapour retarding and vapour permeable tape performance[9].…”