Table of contents:
- Non-smoldering wood fiber insulation board
- Apply plaster to non-glowing wood fiber insulation board
- Avoid cracks and tension
- Winterproof even without plaster
Video: Non-smoldering Wood Fiber Insulation Board
A flame-retardant and non-glowing wood fiber insulation board was used to remodel a former barracks area in Villingen-Schwenningen. Plasterer, carpenter, planner and also the industry worked hand in hand.
Author: Heike Granacher | Photos: Gutex, Martin Granacher
The densification of existing buildings is extremely sensible in terms of general housing shortages and sustainability. As part of this, the 1930s row buildings on the corner of Kirnacher Strasse and Dattenbergstrasse are currently being extended and given a new attic.
While the ceilings are made of solid wood, the wall structure envisages a wooden stud frame with 8/20 KVH stands in a grid of 62.5 centimeters. The stud frame is insulated with mineral wool. The 60-millimeter-thick Pyroresist Wall wood fiber insulation board closes off the F-90 construction; the inside of the walls is covered with 22 millimeter OSB.
Non-smoldering wood fiber insulation board
The wood fiber insulation boards are manufactured using the dry process and, like conventional wood fiber-based ETICS, are installed endlessly horizontally with floating joints. An offset of the vertical plate joints of 30 centimeters must be observed. Cross joints should be avoided. The pressure-resistant insulation boards are fastened with clamps directly on the stands. The permissible maximum distances between the fasteners and the distribution of the fasteners as evenly as possible over the entire floor height must be observed.
Thanks to the flame-retardant insulation board, despite building class 5 and increased fire protection requirements, a simple and therefore inexpensive wall construction was possible. According to the manufacturer, the new insulation board can be processed like conventional wood fiber boards. Thanks to their shock resistance and dimensional accuracy, the hydrophobic, windproof panels should be easy to process. When used as a plaster base plate in the thermal insulation composite system, no additional fire protection bolts are required - this enabled the facade in Villingen to be implemented quickly.
Apply plaster to non-glowing wood fiber insulation board
The newly added floors jump back slightly to the existing building and are separated by a clear component joint. Different movements in the components do not lead to unintentional cracks in the plaster. The wall surfaces are plastered by the local stucco company Karlheinz Hirt. The plaster application began shortly before the start of winter: a second layer of adhesive and filler plaster is applied to the first layer of scraper and the reinforcing fabric is embedded in the outer third of the layer. At the facade openings, e.g. B. windows, additional diagonal reinforcements are incorporated. The drying time is approx. 1 day / mm layer thickness - depending on the weather. The layer thickness of the plaster should be at least 5 millimeters and a maximum of 8 millimeters.
Avoid cracks and tension
The concealed plaster consisting of scratch filler and reinforcement filler is carried out in two steps in order to maintain the base plaster thickness of at least 5 millimeters (max. 8 millimeters per system variant) and the position of the reinforcement in the outer third of the plaster. The reinforcement mesh is laid over the entire surface and overlapping at least 10 centimeters. This prevents cracks caused by tensions in the plaster. Subsequent optional priming regulates the subsurface suction behavior and prevents the plaster from releasing moisture too quickly. At the same time, the primer serves as a bonding agent.
Winterproof even without plaster
The partially finished facade may also be open for a longer period of time and may even overwinter if additional measures are taken into account in the preliminary planning. As soon as an all-day outside temperature of at least 5 ° C is ensured again, the top plaster is applied and the facade is protected with the final coat of paint and the design is completed.
In Villingen, the WBG (Housing Association Villingen-Schwenningen mbH) and architect Bernd Behnisch decided to elegantly contrast the top-up in light gray with the otherwise predominantly white plaster facade. Large front balconies also increase the living quality and are waiting to invite the new residents to relax from spring 2020.
Gutex Pyroresist Wall panels are 1,800 x 600 millimeters in size and have a tongue and groove profile. For the first row of assembly, remove this on the lower side of the panel so that a blunt panel edge is created. Profiled panels are mounted with the spring upwards. The factory stamp on the board surfaces marks the laying side.