When timber acoustic panels are installed the site temperature and humidity conditions are vital for a sucessful installation.
We have published the following guide:
Climatic conditions – expansion and contraction of core materials
As a rule, our acoustic panels are manufactured from MDF (medium density fireboard) or gypsum woodchip boards if a non-combustible fire rating is required. These boards have an 8-10% humidity content during manufacture.
It is vital to check the air humidity and temperature during storage and installation. The DIN (German Industry Standard) 68750/66754 and the SIA (Swiss Engineers and Architects Standard) 164/1 specify the following ranges in humidity and temperature:
- Air humidity in % minimum 35% maximum 60%
- Temperature minimum 18 degrees C, maximum 30 degrees C<?/i>
- Air humidity per m3 minimum 5.5g, maximum 18g
- Wood humidity content minimum 7%, maximum 10.5%
If these standards are adhered to by the installer of our acoustic panels the maximum dimensional change of the MDF substrate amounts to 1.5mm per metre (10.5% – 7% = 3.5% x 0.04% dilatation per 1% changes)
Our acoustic panels must therefore be separated with joints of 3mm to 6mm depending on their size. If this separation is less the following will happen:
- Increasing humidity: joints will be closer or closed and the panels may warp.
- Decreasing humidity: joints will be larger
Our tongue and grooved acoustic planks with their joint free system are installed without a gap between the planks in width. If installation is carried out in high humidity conditions, the planks will shrink in a dry atmosphere – because of the small plank width of 128mm this shrinking is minor and cannot be seen. If the installation is carried out in very dry conditions (e.g. winter time) increases in humidity cannot be absorbed. Planks have therefore to be separated with 0.5mm distance. For swimming pools our acoustic planks are manufactured with a special dilatation profile and moisture resistant MDF substrate (both on request).
General Rule: If installation is carried out in (almost) identical conditions as those when the room will be in use, problems with expansion and contraction can be prevented.
Planks: The front edges of our acoustic planks are supplied with a clean 90 degree angle cut as standard. The length tolerance amounts to +/- 2mm. If requested, the planks can be supplied to a “fixed” dimension with a reduced tolerance of approximately +/- 0.25mm per 1 m. This is only recommended for lengths shorter that 2m because of the potential for greater expansion and contraction of core materials.
Panels: Our acoustic panels are produced on computer controlled machinery with tolerances of +/- 0.25mm per 1 m. Our acoustic products are delivered with small tolerances as above. By grooving and perforating, the surface area is increased by a factor of two or three, depending on the design. Our acoustic products can react quickly to varying humidity and temperature conditions. Therefore size differences can occur before installation caused by expansion and contraction of core materials during storage and acclimatisation.
Transportation and storage: Generally speaking, our acoustic panels and planks must be protected from direct contact with moisture and humid air and be stored in absolutely dry conditions. The products must be stored lying flat on dry wooden planks or pallets. The products must be completely protected from humidity with plastic wrap. Please pay special attention to moisture in the floor in new buildings!
Acclimatisation: The products must be acclimatised for 3 to 4 days in the installation area before starting the installation. Please ensure that all products are equally exposed to the ambient conditions of the installation area. The plastic wrap must be removed during this acclimatisation period.
Natural wood veneers: We recommend sorting the natural wood veneers by their wood grain and colour before installation.
Reinforcement: Removable ceiling panels must be reinforced in the back side to guarantee the panels remain flat. Panels can be flat during installing but will warp because of material fatigue if not reinforced Different climatic conditions in the area below the ceiling and the ceiling void above can result in warping of the ceiling panels.