3.8
Fixations pour bois
Dans la construction en bois, les fixations sont essentielles pour fixer les composants ensemble, la résistance de la connexion dépendant en grande pa…
Dans les structures en bois, les fixations maintiennent les composants en place. La résistance de la liaison dépend principalement du roulement direct des membres.
Différentes attaches, comme les clous, sont des goupilles métalliques pointues enfoncées dans le bois à l’aide d’un marteau ou d’un pistolet mécanique.
Il existe une large gamme de types de clous, avec différents diamètres, têtes et longueurs.
Le clouage frontal, le clouage d’extrémité et le clouage des orteils sont trois techniques utilisées pour fixer les éléments en bois avec des clous.
Les vis, qui sont des fixations à filetage en spirale, sont de différents types et sont installées en appliquant un mouvement de torsion pour les enfoncer solidement dans le bois.
Cette action fait que les filetages tirent fermement la vis dans le matériau qu’elle fixe.
Les boulons sont placés dans des trous pré-percés à l’aide d’une clé pour tourner l’écrou du côté opposé à la tête du boulon, et le boulon est serré et fixé en place.
Les rondelles plates en acier sous la tête du boulon et l’écrou répartissent la force sur une plus grande surface de bois, réduisant ainsi l’écrasement des fibres.
Les connecteurs à anneau fendu, les plaques dentées et les dispositifs de charpente métallique sont également utilisés dans les assemblages d’éléments en bois à des fins de fixation.
View the full transcript and gain access to JoVE Core videos
Q1: What role do fasteners play in wood structures?
Fasteners hold wood components in place and are essential for securing structural connections. Connection strength mainly depends on direct member bearing between fastened components. Various fastener types—including nails, screws, bolts, and specialized connectors—are selected based on specific structural properties and dimensions of lumber to ensure durability and stability.
Q2: How do nails differ from screws in wood fastening?
Nails are sharp-pointed metal pins driven into wood using a hammer or mechanical gun, while screws feature spiral threads and are installed by twisting to embed them securely. Screws' threads pull the fastener firmly into the wood, creating a stronger grip than nails. Both come in various diameters, heads, and lengths suited to different applications.
Q3: What are the three main nailing techniques used in wood construction?
Face nailing, end nailing, and toe nailing are the three primary techniques for fastening wood members with nails. Each method provides different angles and connection strengths depending on the structural requirements and wood member orientation. The choice of technique affects load distribution and overall connection performance.
Q4: Why are washers used under bolt heads and nuts in wood connections?
Flat steel washers distribute force over a larger wood area, reducing fiber crushing and preventing localized damage. When bolts are tightened with a wrench through predrilled holes, washers protect the wood surface from concentrated stress. This distribution enhances connection durability and maintains structural integrity over time.
Q5: What specialized fasteners enhance wood member connections beyond standard nails and bolts?
Split-ring connectors, toothed plates, and metal framing devices serve specialized fastening purposes in wood construction. These connectors enhance load transfer between members and improve overall structural stability. They are particularly valuable in applications requiring higher strength and durability compared to conventional fasteners.
Q6: How does bolt installation differ from nail or screw installation in wood?
Bolts require predrilled holes and are secured by turning a nut on the opposite side with a wrench, unlike nails driven directly or screws twisted in. This method creates a more robust connection suitable for heavy-load applications. Washers placed under both the bolt head and nut distribute force evenly across the wood surface.
Q7: How does screw installation create a secure hold in wood?
Screws are installed through a twisting motion that embeds them into wood, with spiral threads pulling the fastener firmly into the material. This mechanical action creates a strong grip that increases with depth of insertion. The variety of screw types available allows selection based on specific wood type and structural requirements.