Marine Grade Lumber And Its Different Uses

Marine Grade Lumber And Its Different Uses

February 2, 2023

marine grade wood

Marine-grade lumber is exactly what it sounds like, lumber that can be used near or in the water! If your lumber is going to be installed near a consistent source of water, it is likely that stock pressure-treated wood will not suffice. For these types of applications, customers will want to use a more heavily treated wood to withstand the ongoing water exposure. Although specifications for pressure-treated wood often use a classification known as use categories (e.g. UC3B, UC4B, etc.) most pressure-treated wood can be simplified into the following four levels of treatment – Above Ground, Ground Contact, Saltwater Splash, and Saltwater Submersion. Above Ground and Ground Contact is what is typically used for decks and landscaping purposes, and the latter two are for marine use.

Above Ground

Lumber that is treated to the above-ground grade is able to withstand rot or decay for projects that are exposed to the elements but are not in contact with the ground. This lumber has the lightest treatment when making comparisons to other treatment options. Some examples of where this treatment would be used are deck boards, railings, trim, and fascia.

Ground Contact 

Ground contact lumber is best for deterring pests, rot and decay from projects where the lumber will be in contact with the ground. Some examples of projects that may use this type of treated lumber include, but are not limited to; fencing and decking posts, retaining walls, and flower boxes

Saltwater Splash

Saltwater Splash is a treated lumber used in projects where the lumber is installed near a body of water and that water could splash onto the wood. This treatment is a bit stronger than the ground contact, due to the fact that water and moisture will lead to decay faster than lumber that is not subject to contact with high levels of moisture. This lumber would be used in projects such as piers or some boardwalks.

Saltwater Submersion

Salt Water Submersion is for lumber that will be constantly and completely submerged in water. This is one of the strongest treatments that you can get. Because the lumber will be continuously submerged in water, it needs to have the highest resistance to rot as possible, otherwise, it could make your project unsafe for use in the long term. Piling is one of the more common types of marine pieces that are treated to this grade as they are used on projects like piers and bridges.


Whether you need lumber treated from Above Ground to Salt Water Submersion, we can help!  As always, here at Frisco Woodline we supply all lumber and treatments and would be more than happy to answer any remaining questions that you may have. If you are looking to get a quote, we can help you with that as well!