Casa Peumayen / Aguilo + Pedraza. Image © Timber

How to Design and Build a Wooden Structure with Hidden Joints

由专筑网李韧，王雪纯编译

数字建筑新技术正在逐步改变着人们的设计与建造方式，诸如计算机数控系统（CNC）等，其准确的精度使得人们能够设计出完美的构件，比如包括隐藏各种节点的金属作品，以及耐久、易于建造、体系精准的建筑作品。为了更好地了解木结构的建造过程，以下是重要的设计技巧。

New technology in digital building, particularly Computer Numerical Control (CNC) systems, are changing the way that we design and build wooden structures. Their high level of precision allows us to design perfect assembles--without screws or visible metalwork--resulting in structures that are durable, easy-to-build, and extremely well-organized. We spoke with the experts at Timber to better understand the process of building a wooden structure and to compile a list of key tips in designing one.


Casa Peumayen / Aguilo + Pedraza. Image © Timber

1、选择能够机械化的木材类型，并且有着明确的截面

要让木结构机械化，你需要了解木材的类型，并明确其截面。这能够防止项目到后期一改再改。

但是，许多建筑师在设计木建筑时，其横截面都并不存在，因为这需要经过耐久度与刚性需求的计算，要么就是木材无法进行机械化，最终结果这就导致在各个事情都完成之后来改变整个系统。如果在结构类型这方面缺乏经验，那么建筑师最好和专家进行沟通。

1. Choose wood types that can be easily mechanized and clearly define their sections.
To mechanize a wooden structure, you need to keep in mind the type of wood that you want to use and clearly distinguish its different sections. This will help prevent changes in the later stages of your project.
Surprisingly, many architects design their structures with sections that don't even exist--thanks to calculations done according to durability and rigidity requirements or because the wood chosen for the project cannot be mechanized, resulting in the need to change the entire system once everything is laid out. If you lack experience in these types of structures, it would be wise to consult with experts who can guide you through the process.  


Typical sections for pillars and wooden beams. Image © Timber


© Timber

2、了解不同木材的特性，了解其随着时间而变化的程度

举例来说，我们可以比较一下蒙特雷松木和俄勒冈州松木两种木材的特性，了解一下它们的层压特征与木材形式。

俄勒冈州松木对于湿度、白蚁、霉菌等外部干扰分有着很强的抵抗力，因此在用在外部结构之中，这种木材是首选。但是如果用作硬木，俄勒冈州松木便没有那么适合，这种材料会随着时间持续的受损变形，并且后期不易复原，而蒙特雷松木在这方面就更加稳定一些。

就预算来说，建议选择层压形式木材，因为安装之后，无论哪种松木，它们的形式都不易改变。另外，当然也有多种多样的天然饰面可以选择，这样能够为木材增添保护层，让其更耐久，甚至可以维持长达15年。

2. Study the different types of wood to understand their properties and how they change over time.
To give you an example, we will compare the properties of Monterrey Pine with Oregon Pine, taking a look at their laminated or hardwood forms.
Oregon Pine is highly resistant to humidity, termites, and mold, making it a recommendable choice for exterior structures. However, as hardwood, after being laid, Oregon Pine has the tendency to continuously shift, leading to damage and deformations that can prove difficult to fix. Monterrey Pine, on the other hand, is more stable and is a better choice for this type of use.  
If it fits into your budget, we recommend that you choose laminated formats since they stay exactly the same from the time that they are installed, whether they're Oregon or Monterrey Pine. However, there are also a variety of natural finishes to choose from that give even more protection and durability to all types of wood, and that can last for up to 15 years.   


CFT ARAUCO DUOCUC / GDN Architects. Image © Aryeh Kornfeld


CFT ARAUCO DUOCUC / GDN Architects

3、考虑项目的地点，以及材料的吸水性

如果是在干燥的室内应用木材，那么无论是建筑的哪个部位，都应保证使用耐久性高的材料。但是如果建筑位于沿海地区或是湿润的环境之中，那么就可以适当地缩小木材尺寸，减少其遇水的机会。

3. Consider the location of your project and its tolerance to moisture swelling.
If you choose wood dried in a chamber, the degrees of humidity in the finished structures should remain stable, no matter the structure's location. However, if your project is on the coast, or in a humid environment, it's possible to modify the wood's tolerance, such as reducing its dimensions by a few millimeters to combat the swelling from contact with water.


El Galeno马厩和仓库｜El Galeno Horse Stables and Warehouse / Peñafiel & Valdivieso Arquitectos. Image © Francisco Croxatto Viviani


El Galeno马厩和仓库｜El Galeno Horse Stables and Warehouse / Peñafiel & Valdivieso Arquitectos. Image © Timber


El Galeno马厩和仓库｜El Galeno Horse Stables and Warehouse / Peñafiel & Valdivieso Arquitectos. Image © Francisco Croxatto Viviani

4、木材越大，抗火性能越好

就建筑结构来说，层压木材能够有效地抵抗火灾，这一点甚至比钢材更加优越，因为层压木材只会燃烧其外层。

举例来说，如果项目需求的木材耐火时间是R30，意味着建筑在火中需要维持至少30分钟，假设结构木材的尺寸为42x150毫米，如果其截面每增加0.7毫米，那么耐火时间就能增加1分钟。而如果耐火时间要从R30变为R60，那么木材的厚度就应该增加2.1厘米。

4. The larger a piece of wood is, the greater its resistance to fire.
In the case of structures, laminated wood is effectively resistant to fire, even more so than steel, as it's only its outer layers that burn.  
For example, if an R30 fire resistance is needed (meaning that the structure will continue with its functions for at least 30 minutes) and the structure has a 42x150 mm piece of wood, you can add up to 1 minute of resistance by increasing the section by 0.7 millimeters. This means that, you should add 0.7 mm to get one minute of resistance. To go from R30 to R60, for example, you should increase the thickness of the wood by 2.1 cm.


© Timber

5、隐形节点的功能与美学

除了传统的金属制品，一系列的隐形节点与组件可以通过螺栓和其他金属构件相连接，它们可以将几种木头、或与其他材料连接在一起。

5. The function and beauty of hidden joints
Along with traditional metal workings, there are a series of hidden joints and assemblies that can be attached with bolts or other metal pieces, connecting wood with wood or wood with other materials like concrete.


© Timber

数控切割较为精准，降低了项目的成本，一般来说，节点部件可以通过模型、图纸的方式精确地表达出来，并且能够与Revit以及数控切割机器相结合使用。

Cutting done by CNC results in a high level of precision, lowering the general costs of a project. Generally, the structure can be easily modeled by Cadwork software, compatible with Revit and other CNC machines.


© Timber

以下是一些常用的节点：

鸠尾接合

有着梯形切口，其一端一般大于另一端。

Some of the most used combinations include:

Dovetail Joint
Made with a trapezoid-shaped cut, one of its extremes is always wider than the others.


Dovetail Joint. Image © Timber


Dovetail Joint. Image © Timber

榫卯节点

将其中一个部件经过精准的切割与打磨，从而与另一个部件完美无缝地连接在一起。

Mortise and Tenon Joint
Achieved with a precise cut into one of the pieces, allowing the other piece to be tightly fitted connected with the other.  


Mortise and Tenon Joint. Image © Timber


Mortise and Tenon Joint. Image © Timber

隐藏式金属连接器

可以用于连接金属与诸如混凝土等其他材料。

Hidden Metal Connectors
These connect wood with other materials like concrete.


Hidden Metal Connectors. Image © Timber


Hidden Metal Connectors. Image © Timber

6、明确规范能够有效降低项目成本

在设计的时候应该结合当地的规范要求，如果规范看起来不完整或不清楚，则可以查阅其他国家设定的更高级的规范，从而保证建筑设计方案的有效性。例如欧洲的Eurocode 5就给出了设计与建造木建筑各个方面的规范，可以作为木结构项目的指南。

在一些规范没有涉及到的区域，工程师们往往会尤其注重此方面的安全性。

6. Guiding design through clear regulations can reduce project costs
It is fundamental to always design with norms in mind. If norms appear incomplete or unclear, it's possible to look to more advanced norms set by other countries, ensuring the efficacy of your structure. For example, Eurocode 5, which covers all aspects of designing and building wooden structures, is a good guide for these types of projects.
When norms leave too much room for chance and speculation, engineers tend to increase the safety percentage by unnecessarily adding onto the structure.


© Timber


© Timber


Casa Peumayen / Aguilo + Pedraza. Image © Timber


House on the Rocks / Schwember García-Huidobro Arquitectos. Image © Nicolás Sánchez


© Timber