Deck building is an important part of the overall home maintenance process. Proper footing is key to a safe and long-lasting structure. Poured piers are best, although on-grade cement blocks might work if the frost line is not too deep.
Concrete deck blocks are more susceptible to movement over time, but a bit of movement shouldn’t hurt your new deck. Contact Deck Builders Murfreesboro TN for professional help.
A beam is a structural member used to resist loads applied laterally to its axis. It is an important part of any structure, including decks. Beams can also be referred to as members, elements, rafters, shafts, or purlins. Beams can be found in a variety of shapes and sizes, and are often made from steel. Beams can be fixed or free-standing and they may or may not be joined to other structural components, such as joists and girders.
Typically, a deck plate is placed beneath the beams to distribute horizontal wind and wave loads to the main deck plate and superstructure. The size of the deck plate is determined by the equipment, supplies and crew loads that will be loaded on the deck. This information is obtained from the deck equipment and production designers in the conceptual design phase.
The deck plate may be thickened around wheeled loading areas, forklifts and other wheeled vehicles and also in the vicinity of deep tanks. It is also thickened at the ends of the deck in order to withstand deck sway caused by heavy equipment and cargo loads.
The psf load rating determines how much weight the deck can support per square foot. This rating affects joist size and spacing, beam spans and post placement to ensure the frame can safely carry the loads. For example, a higher psf rating may require larger joists and closer joist spacing to reduce deflection, or it may require shorter beam spans and more mid-span posts to distribute the load evenly.
The rim joists are the outermost flange of the deck framing. These joists may align with the deck edge or be inset. Rim joists are typically the same size as the deck joists–commonly 2×8, 2×10, or 2×12 pressure-treated lumber–to provide consistent support throughout the frame.
Joists
Joists and beams play interconnected roles in the overall structural integrity of a deck. Beams support walls, ceilings, and floors, while joists are the horizontal supports that distribute the weight of a deck’s surface and furniture. Joists are also responsible for preventing sagging or warping over time. The right joist materials, design, and arrangement ensure a safe and long-lasting structure.
While both joists and beams are important for a sturdy deck, joists are especially crucial because they are responsible for supporting the floor of a deck. Standard dimensional lumber joists can provide adequate structural support, but engineered wood products such as I-joists offer increased strength and capacity, reducing the number of joists needed and allowing for longer spans.
In addition to ensuring the joists are spaced appropriately, proper installation of blocking will prevent sagging and other common problems. Decking materials, furniture, and foot traffic all impose significant pressure and weight onto joists, and joist blocking evenly distributes this load to avoid putting too much stress on one joist. Joist blocking is often placed in a zigzag pattern between joists to create a rigid framework and reduce bounce, sway, and lateral movement.
Another important step in deck building is applying joist tape, which protects joists from moisture and prolongs the life of your deck. This is a necessary step in regions with heavy rainfall or snowfall, where joists are particularly vulnerable to water damage.
Before starting to build your deck, check the local building codes and your homeowner’s insurance policy to find out whether you need a permit. If a permit is required, follow the process carefully to ensure that your project meets all building codes and is safe to work on.
Footings
Footings are an essential part of deck construction, as they serve as the foundation for the structure. They transfer the weight of the deck to the ground, helping it withstand external forces like soil changes and frost heave. By distributing the load across a wider area, they also prevent sagging and shifting that can compromise the safety of the deck.
Footing depth is another important factor to consider, as it determines whether or not a deck will be able to withstand seasonal changes in temperature and moisture levels. Insufficient footing depth can lead to the structure moving and sinking, which can cause damage or even collapse. Proper depth can minimize the risk of these issues by ensuring that the footings are properly below the frost line and meeting local building codes.
Deck footings can be made from a variety of materials, including concrete and steel. Concrete footings are often preferred due to their durability and ability to be molded into unique shapes to accommodate specific design requirements. However, they can be more expensive than other options and require more time to install, which may delay your deck build.
Alternatively, steel footings are more cost-effective and durable than concrete. They’re also easier to install, reducing labor costs. They’re also resistant to corrosion, making them a great choice for outdoor use. Lastly, helical and H-pile footings are another option, but they’re typically more expensive than other types of footings and may not be suitable for all soil conditions.
While footings are essential for safe and secure decks, they can be difficult to build. It’s crucial to consult with a qualified contractor who has experience in the field and understands the importance of proper installation to ensure that your deck is safe, sturdy, and compliant with local building codes.
Support Posts
A deck’s posts support the joists and transfer the weight of the deck and everything on it-people, furniture, snow-to the ground. They also support the ledger boards that connect the deck to the house. The type of posts used depends on the size and layout of the deck and local building codes. Post spacing is very important because it impacts the structural integrity of the deck and can affect the aesthetics of the home.
Generally, single-piece, steel, permanent posts are preferred for long-term stability. They are hollow and, when installed, should have an ICC or BOCA sticker (sometimes removed after installation) to indicate third-party evaluation to ensure they meet specific design criteria. Posts may be screwed to the footing with an adjustable end or fixed in place by a flat steel plate (flange) end that is either cemented or bolted into the basement floor. Temporary posts are often found on older homes and are usually less than 3” in diameter. They come in multiple pieces with smaller sections fitting inside larger ones that are fixed in length by metal dowels. Home inspectors will occasionally find these multiple-piece temporary posts installed as permanent posts in a home and this should be investigated as it indicates non-professional structural work that might lack proper engineering or permits.
Homeowners should carefully plan outpost locations before construction to avoid costly repairs. They should also consult with a structural engineer or professional deck builder to verify their plans comply with safety standards and other local building codes. For example, the psf load rating (a number set by local code) determines how much weight can be supported per square foot and influences joist size and spacing, beam spans, and post placement.
Piers
Piers are one of the fundamental elements that provide stability and support to structures like bridges, buildings, and marine facilities. They are a critical part of the construction process, and their design and construction require careful consideration of environmental factors and structural loads.
There are several types of piers available. The type that you choose depends on the specific needs of your building. For example, a working pier typically has features that make it easier to access marine vessels for loading and unloading. These piers are usually constructed of concrete because it is an extremely strong material that can bear a substantial load and resist corrosion. Other piers are designed for recreational use. Pleasure piers, for instance, are built with features that cater to fishing activities such as spots where you can clean and gut freshly caught fish. Other piers are designed to reach ideal deeper waters where you can enjoy leisurely marine vessel activities such as boating or swimming.
In terms of construction, pier foundations are used for large-scale projects such as bridges and skyscrapers. They are also commonly found in areas where soil conditions are not favorable for a spread footing or other types of foundation. They are constructed from steel or reinforced concrete and are driven into the ground until they reach a firm layer of soil or bedrock.
There are two primary pier types, push and helical. Helical piers are more expensive than push piers, and they are typically chosen when an extensive amount of work is needed to dig down to the required depth. In general, however, most contractors prefer push piers because they can be installed more quickly and with less labor than a helical pier.