Presentation MHM system
MHM system, solid wood ecological wall

They are thick and massive walls featuring extraordinary insulation caused by wood’s outstanding physical properties, incredible ability to store heat and reduce heating costs and shape stability caused by the crossed layers structure of dried boards: these are only some of the peculiarities MHM system (Massiv-Holz-Mauer) features.

The wall is an ecological structure conceived for residential housing and further applications and it is made up of 24-mm-thick dried boards of different lengths.

During the preliminary phases of the work, boards are provided with a 3-mm-large abutment through a milling machine, and then profiled with numerous 3x3 mm side grooves.

These profiled boards are then processed by a Wandmaster which produces raw elements in sizes ranging from 1,50 x 1,50m to 3,25 x 6,00m and thickness ranging from 11,50 to 34,00cm.

Boards are pressed, crossed (both longitudinally and crosswise) and assembled through aluminium nails without the use of any glue.
Every intersection is assembled crosswise through the use of two nails which are placed as far as possible from each other.

Once obtained the desired thickness, the raw element is transferred to a numerically-controlled work centre (PBA), where it is shaped and provided with the necessary openings for doors and windows, which are listed within your architectural plan.

During this phase even holes for slings, grooves and carvings for heating and water system are automatically realized, as well as sockets and further applications for electrical systems. After these procedures, the wall, which is ready to be installed, is sealed to the facade through a special water-repellent mortar which protects it during assembly.

This is the way both internal and external walls are created, and they will be stored vertically inside special devices up to the time of assembly.

MHM walls can be used both internally and externally, can be bearing or not and can be employed as both common and partition walls..

Static characteristics
Explanation of the static data

Employed aluminium nails must comply with building licence Z-9.1-563. Traditional boards are 18 cm large. Larger tables occasionally cause much trouble due to the higher number of joints they involve, glass strain excluded.

The wall’s capacity load was calculated according to Appendix D of E DIN 1052:08/03 through the help of cutting analogy. It was observed that upon maximum capacity load for all kinds of stress mentioned, joints represent valid dimensioning values.

As far as the stress of glasses and panels is concerned, loading values for unit loading 1 of walls featuring various thickness and height are represented. Since both load capacity nails and stress feature a linear status, values could be accordingly adapted to the load and the length of the wall. Upon normal stress conditions, calculations are carried out according to II-order theory. Upon non-linear status, different schemes are represented for different thickness and height. Through the value which indicates the stress of the wall it is possible to measure both nail stress and strain.

Upon combined strain, values must be superimposed.
Both the direction of nail stress and strain are represented.

To display a test carried out on crossed boards which were glued but not NAILED DOWN as MHM walls, visit following link:
http://www.youtube.com/watch?v=pI3tMQ20mzs

Wall description
Fire protection class F 90 B

Solid wood walls are ecological structures conceived for residential housing; they are made up of 24-mm-thick dried boards of different lengths.During the preliminary phases of the work, boards are provided with a 3-mm-large abutment through a milling machine and then profiled with numerous 3x3 mm side grooves.

These profiled boards are then processed by a Wandmaster which produces raw elements in sizes ranging from 1,50 x 1,50m to 3,25 x 6,00m and thickness ranging from 11,50 to 34,00cm. Boards are pressed, crossed (both longitudinally and crosswise) and assembled through aluminium nails. Every intersection is assembled crosswise through the use of two nails which are placed as far as possible from each other.

Once obtained the desired thickness, the raw element is transferred to a numerically-controlled work centre (PBA), where it is shaped and provided with the necessary openings for doors and windows.

During this phase even holes for slings, grooves and carvings for heating and water system are automatically realized, as well as sockets and further applications for electrical systems.

A complete production line for M-H-M walls covers a surface of about 40m x10m and can produce about 6.000 m² of walls’ elements a year. After these procedures, the wall, which is ready to be installed, is sealed to the facade through a special water-repellent mortar which protects it during transport and assembly.

This procedure allows to optimize the U-value (the employed mortar is a mixture of wax, sunflower oil and sawdust ). This is the way both internal and external walls are created, and they will be stored vertically inside special devices up to the time of assembly.

Wood species: spruce, silver fir, pine WAINSCOT PANELLING
• Trim width: 10 – 30 cm
• Thickness: 24 mm (set value)
• Humidity: 14 ± 2 %

STANDARD:
• Wood fibre deviation: max. 16 %
• Medulla: admitted
• Annular width: unlimited
• Wood shrinkage: admitted
• Cracks caused by lightning, ring shakes: not admitted
• Bevel: up to 1/3 of the cross section, without bark
• Longitudinal warp: up to 12 mm every 2 m
• Twisting: up to 5 mm every 2 m
• Warping: up to 5 mm every 10 cm
• Blueing: admitted
• Brown and red veins resistant to nail scratches: admitted
• Dry rots: not admitted
• Compression wood: up to 3/5 of the board’s width
• Insect attack: not admitted
• Holes caused by insects: admitted, provided they do not impair resistance

Cell drying: at a temperature of 65°C for at least  8 hours to wipe insects out. Test carried out through automatic drying protocol.

Nodes: Max. diameter  ½ of the board’s width, not-adherent nodes admitted, rotten nodes not admitted.

Technical specifications MHM

Download technical specifications * (PDF format, about 3MB)

CAD 3D

The drafting and design ofSOLID WOOD WALLS is performed through CAD. The architect working at the planning department has the simple task to send all relevant documentations to the manufacturer of SOLID WOOD WALLS via the Internet.

During the preliminary phase, received data are checked and the building planned together with the architect, so that the house is erected according to the design engineer’s requirements.

Even carvings, niches and difficult passages designed by skilled engineers (heating, electrical system, sanitary fixtures and ventilation) are included in the CAD planning.

When all parameters are set, SOLID WOOD WALLS are produced through a CNC-controlled assembly line.

Transport and assembly

Prefabricated walls are delivered by road through special trucks.

Intermediate floor

We employ two kinds of Fir or Larch intermediate floors.

Picture 1. Solution based on thin boards (from cm 12,00 to cm 18,00) put together featuring “openings” from 4mtl to over 10mtl, firm and compact structure.

Picture 2. The most popular solution which is employed in traditional masonry too, made up of relief truss and stopping planking. Examples:

Rafstore
Rafstore is a modern and practical dimming system which can be controlled from the inside of the house both manually and electrically through a centralized radio control.
Several colours available. Below some descriptive pictures

Window shutters
The shutters we employ differ from traditional ones for the way they are anchored to the wall. Below some pictures depicting the different kinds of shutters we employ.

Covering roof: it is available in different versions which are all insulated through wood fibre, vapour-based breathable cloth and ventilation. Here some examples:

Download PDF to display available models.

Reinforced concrete

Example of reinforced concrete foundation bed. After the engineer dealing with static calculations has established the technical characteristics the bed should have, foundations are laid taking into account future connections to the piping system, so that it won’t be necessary to bore external walls again or mark out the bed, thus compromising insulation and bringing about additional charges. By acting like this, we will also facilitate the work of technicians you CAN personally choose.

Ventilated wooden foundation bed

VENTILATED FOUNDATION BEDS are manufactured to give people the possibility to take advantage of a natural ventilation which makes THEIR HOUSE drier and healthier.

The whole structure is separated from the ground by a zinc-coated steel leading frame made up of IPE  horizontal beams and can be anchored in two different ways:

1. Oakenpillars anchored to the ground, a widespread solution in Northern Europe

2. Reinforced concrete vertical pillars with anchorages. Both solutions ensure utmost performance since they are designed according to static calculations and in compliance with applicable earthquake-proof and environmental regulations.