WALL2DN is a simple, user-friendly, integrated two-dimensional computer model to predict the fire resistance of either insulated or uninsulated, non-loadbearing wood-frame wall assemblies finished on both faces with gypsum wallboard.
WALL2DN is written in Microsoft Visual C++ 6.0, and can be run on most personal computer systems with WINDOWS 95® or better operating systems. WALL2DN has a simple, user-friendly interface that permits architects, building-code officials and engineers to easily create custom-designed walls and then estimate the fire-resistance ratings of those assemblies. As well, WALL2DN allows users to compare the model's theoretical predictions with the empirical results from any of six standard fire-endurance tests.
WALL2DN can be used to investigate the fire resistance of wood-stud walls with the following construction options:
· three grade-species of lumber: SPF, Douglas fire, southern yellow pine,
· two sizes of studs: 28 mm x 89 mm (nominal 2 x 4) and 38 mm x 140 mm (nominal 2 x 6),
· two spacing distances between studs: 400-mm o.c. (16 in.) and 600-mm o.c. (24 in.),
· two types of gypsum board: generic Type X and proprietary Type C,
· two thicknesses of gypsum board: 12.7 mm (1/2 in.) and 15.9 mm (5/8 in.),
· single and multiple layers of gypsum wallboard attached directly to the two sides of the walls,
· varying spacing-distances between the fasteners used to attach the gypsum wallboard to the studs,
· if insulated, either glass-fibre or rock-fibre insulation filling the cavities between the studs, and
· if insulated, varying densities of insulation.
There is very good agreement between WALL2DN’s predictions and the observations and measurements taken during standard fire-endurance tests for the following:
· two dimensional heat transfer (temperatures) in wood-frame walls,
· deformation or gypsum wallboard during fire exposure,
· loss of joint compound,
· fall-off of the gypsum wallboard,
· melting/shrinking of glass-fibre insulation,
· charring of the wood studs, and
· “insulation failure’ of wood-frame walls.
While the following features are not currently available in WALL2DN, many will be added to future versions:
· heat transfer through floor-ceiling and roof-ceiling assemblies,
· dimensional shrinkage of wood members resulting from loss of moisture during fire exposure,
· application of structural loads on wall assemblies and the ability of the assemblies to support those loads during fire exposure,
· validation data for other wall designs,
· pre-loaded non-standard fire exposures,
· attachment of the gypsum wallboard to the studs using resilient channels,
· wall assemblies constructed with two rows of studs (e.g. either staggered or double-row), and
· wall finishes other than gypsum wallboard (e.g. OSB or plywood).