Fuktsäkerhetsgranskning av nybyggnation - Byggnadsfysik - Lunds ...

Abstract
The undoubtedly greatest "enemy" for a building engineer is moisture impact
during the construction process. Moisture damages are expected to cost
billions of SEK for the society annually. In addition, the moisture-related
problems jeopardize the health and wellness of human beings. The moisturerelated
damages stand for more than 80 percent of all damages in buildings.
New buildings exhibiting moisture damages during construction or after a
few years of management is not uncommon in the construction industry.
Examples of construction projects that have demonstrated moisture damages
in the early stages include 2000s large residential areas such as Mariastaden in
Helsingborg, Annehem in Lund and Hammarby Sjöstad in Stockholm.
In addition, the climatic conditions in the future are predicted to give more
intense weather with more rain and more flooding in accordance to SMHI's
(Swedish Meteorological and Hydrological Institute) climate scenarios. With
this in mind, an even more thought-out moisture safety planning of
construction projects is required to minimize moisture damage risks.
In this thesis, a new construction built in Skåne has been reviewed. The
contractor has chosen to remain anonymous and therefore not mentioned by
name in this thesis. The study includes a block with a garage space underneath
the block. Total five buildings are built in three to five stories. The houses are
built with prefabricated sandwich walls, infill walls of steel and wood and
floor joists of hollow core slabs.
The investigative part of the thesis is consisted of three sections; moisture
safety review at the planning stage, moisture safety review under construction
and additional moisture calculations.
My studies of moisture safety points to a series of errors, both during the
design and construction phase. During the design stage, it appears that the
critical points consist of too high supply and installation moisture content of
wood in the infill walls. It also appears in the design documentation, that an
unfortunate combination of steel and wood materials has been used in the
infill walls.
During the construction phase the largest source of disturbance has been the
lack of weather protection, which led to large amounts of moisture which
moistened the constructions. The problems have worsened due to the location
of the construction, which is very wind-exposed.
Moisture calculations indicate that the wood studs in the infill walls receive
high relative humidities with a high risk for mould damages. In addition, the
required installation moisture content of wood was inappropriate from the
moisture safety aspect.
Proposed measures, to improve moisture conditions in the buildings, include
weather protection of the constructions, additional insulation with 50 mm
Västkustskiva and lower installation moisture content. All these measures give