Materials

Options are just one of the many benefits of building with timber - YBC offers numerous choices for materials depending upon your climate and site requirements.  You can choose from our standard materials or combine any of the options below to create a unique timber bridge for your project.  At YBC, even our standard materials are of above-average quality.  YBC's experts will be happy to offer recommendations regarding the proper materials for your project.

YBC believes that when you start with the right ingredients, you always end with a better product. 

 

Hardware:

• Galvanized Lags - standard on structural deck on a Vehicular Bridge.

• Heavy Duty AISI Grade 305 Stainless Steel Screws - standard for the pedestrian guiderail and fastening the wear deck to the structural deck.  Superior corrosion resistance under all conditions.  Used instead of nails to minimize loosening connections over time. 
• Heavy duty ASTM A-307 hot-dipped galvanized timber bolts (shown at right) - standard.
• Premium construction wood glue, in addition to the fasteners, to minimize cupping and warping boards - standard on weardeck and certain guiderail applications.
• Simpson hangers (brackets) - hot dipped galvanized, various types.  Used to join piling caps, stringers, piling or glulams to the corresponding material.
• Upgrade to all stainless steel fasteners for every part of the bridge.  May be recommended in marine or high salinity environments or in areas with severe weather. Some clients opt for this to ensure even greater longevity of their bridge.
• ASTM F-844 dock washers to minimize twisting lumber and maximize holding power of the bolts - standard.

Lumber:

Southern Yellow Pine

• #1 Dense and #1 grade pressure treated Southern Yellow Pine - standard on nearly all parts of the bridge.   #2 grade pressure treated used in limited application, such as the piling caps.  Used in areas of the country where Southern Yellow Pine is the common species of tree. 
• Upgrade to #1 Grade, #1 grade dense or any higher grade lumber is an option on any project.

Douglas-Fir

• #1 Dense and #1 grade pressure treated Douglas-Fir - standard on nearly all parts of the bridge.  #2 grade pressure treated used in limited application, such as the piling caps.  This is often the YBC standard used in the Western United States where this species is most commonly found.  In other areas and climates, upgrading to Douglas-Fir is an attractive options for many clients.  
• By nature, Douglas-Fir is more dense than Southern Yellow Pine, proving to be a great material for the Arid Climate in the West, compensating for the rapid drying process that climate produces.  The density of this material is an additional defense to warping, twisting and cupping.
• Being a heartwood, Douglas-Fir is difficult to penetrate with treatment.  To aid in this process, a practice known as "incising" is utilized.  Incising is cutting or boring a series of slits or holes into the wood, generally 1/4" to 3/4."  This is required for adequate treatment of Douglas-Fir and results in a deeper, more uniform treatment.

• Our standard Glu-lam Beam is Douglas-Fir treated with Penta (Pentachlorophenol).

• Upgrade available to architectural quality glu-lams or Southern Yellow Pine glulams for their aesthetic value.

Additional Options for Lumber

• Upgrade to exotic or hardwood timbers, such as IPE or Green Heart Piling.  Hardwoods greatly add to the strength and beauty of the bridge, and may not need to be pressure treated.  IPE, for example, is deep, rich brown in color and will not weather to gray over time with the proper staining.  It is so much stronger than conventional lumber that YBC can use smaller members and still achieve the same structural integrity - a 3x3 IPE post is the structural equivalent to a 4x6 post of standard lumber.
• Upgrade to composite and/or recycled decking material.  Composite materials present a more polished, uniform appearance; however, due to the nature of the material, YBC may not be able to build from the deck level.  Please ask your Sales Rep for further information. 

Treatments:

• For Southern Yellow Pine, CCA is standard.  CCA is typically used for any piling in salt water and for heavy timber construction.  Treatment is minimally leaching and EPA approved for construction use.
• ACQ can be used instead due to environmental constraints.
• ACZA standard on Douglas fir lumber.  
• Pentachlorophenol (Penta) treatment is used on all Douglas fir Glu-laminated beams.
• Upgrade to oil based preservative treatment.  This treatment can minimize the need for future sealing of your timber bridge.  Highly recommended in arid climates.
• For an antiqued look, YBC recommends oil based treatment with Douglas-Fir lumber for the immediate feeling of warmth.
• Upgrade to 21Poly polymer coating for piling, lumber and timbers.

Additional options:

• Plywood construction matting to protect the bridge from damage or marks.  Also protects the wetlands from oils or fluids from the equipment.  Highly recommended for Boardwalk complexes, when using composite materials and on any bridge greater than 200' in length. 
• High-quality bridge sealant.  Highly recommended every 2-4 years, unless the lumber is treated with an oil-based treatment.