The Basics of Floor Assembly in a House


Concrete capping is sometimes laid to prepare the subfloor for tile or radiant heating pipes. This assembly is where the ductwork for the forced air system and other plumbing and electrical lines will be put.

Building Floors

There are three primary floor configurations employed in contemporary buildings. These include both prefabricated joist systems and framed, truss-style flooring.


Framed floors are the most widespread type of flooring system. The term “floor joists” refers to the dimensioned lumber that rests on “load-bearing walls” or “load-bearing beams” located both within and outside the building. The joists for the floors are typically set at 16″ intervals. Rim and trimmer beams are nailed down to complete the perimeter before the floor joists are nailed on top. Strapping or bridging prevents the posts from twisting in their bearings. Gluing the subflooring to the joists as installed is another way to stop this kind of twisting. Unless metal hangers give sufficient bearing support against other structural components, all posts must extend at least 1-1/2″ onto a bearing assembly consisting of a beam or an entire height wall. For longer spans, builders use laminated joists, built-up beams, or one-piece, solid load-bearing beams made from logs or manufactured lumber. To install utilities, electricians, and plumbers must frequently make cuts or drill holes in the joist work, which is generally OK as long as no more material is removed than is required by building requirements. This flooring option typically has the lowest initial cost.


All truss flooring is made out of trusses. Small pieces of lumber are used in their construction, and metal or wooden plates are used to join them in a latticework pattern. Trusses are sometimes constructed on location, with plywood plates serving as connectors for the webwork. They are typically spaced 24 inches apart, mounted on bearing walls or beams, or framed with plywood rim joists. Strapping is attached to the underside to stop the typical problem of deep truss parts twisting in situ. Bearing lengths of at least 3 inches are commonplace in the context of long-span truss work. Trusses can be constructed to span the entire building, unlike framed floor assemblies, which are limited to supporting only the center of the structure’s weight. They are more costly than framed floor assemblies but deliver an exceptionally sturdy floor that doesn’t “bounce” as much. The structural system’s webwork components also allow for the easy installation of utilities. Truss members are explicitly designed for the loading conditions they will experience throughout the building’s lifetime. Hence no alterations must be made to them by the trades.


The relatively new prefabricated joist is typically made from inexpensive materials to resemble a steel I-beam in more significant buildings. This means that the post has a thicker top and bottom edge, with appetite typically interlocking between them in the vertical direction. These systems are so sturdy that they can usually span the whole length of the structure. The joists on this type of floor need to be hung in a particular way, either from other posts or beams, or bearing walls, which can be costly to custom-make. Because of their low price, decreased labor time, and sufficient support, manufactured joists quickly replace traditional flooring systems. Contractors, however, should study up on its installations since improper use can seriously harm the posts. A three-point beam with an uncut top chord over the central bearing point is an excellent illustration of this problem.




Typically, three types of sub-flooring are used, each with its own purpose. The completed floor will be laid atop this. You can choose from the raw sheathing, interlocking, or strip subflooring. It is used to protect the building from being subjected to twisting or torque pressures and serves as a surface upon which the interior finishes can be installed. Loads can be distributed using the joist framework, supported by the sub-floor. Sub-flooring is frequently attached to the posts to avoid creaking floors and keep the floor joists from turning.


The raw sheathing is typically installed as 3/4″ thick plywood panels and comes in 4′ x 8′ sheets. Sheathing of this type can be used to bridge joists up to 24 inches apart. The sheathing is laid so that no two edge joints are parallel on adjacent sheets. It requires little effort to set up and can be done quickly. Nails or flooring screws of 1-1/2″ in length are used to secure the sheets at a distance of about 8″ apart. Backers or supports under joints, between sheets that run perpendicular to the framed floor assembly, are a good idea even though they are not strictly necessary.


Interlocking sheathing panels are the standard. Sheathing like this is typically 5/8″ thick and comes in 4′ by 8′ sheets made of plywood or aspenite (also known as “chipboard”). The sheets’ long edges feature a tongue on one side and a grove on the other, allowing them to lock together securely. The sheets are put in the same way as raw sheathing: pushing or pounding them together before nailing or screwing them to the joist construction. It is commonly the most cost-effective to set up.

Once upon a time, subfloors made of strips were the norm. However, its use has decreased as manufactured sheathing alternatives have become more widely available. Strip flooring comprises 1″ by 6″ or 8″ boards arranged on the diagonal above the floor joist framework. It demands skilled professionals and comes at a higher cost. Non-kiln-dried lumber with reasonably high moisture content is required to properly install such floors. This may sound counterintuitive, but it’s true that wood contracts as it dries out. Drawing the floor closer together as it contracts makes the whole structure more robust. The subfloor’s strength and longevity are its best features. The 1/4″ to 1/2″ gaps often left between individual planks after wood dries out can cause a lot of annoyance for homeowners. When the floor is finished, the voids are not evident and do not affect the subfloor components, but they might be unsightly during construction. The joints in a strip floor are made to fit snugly together, either by lapping or by being spaced apart.


Completed flooring


The completed floor, which we see and tread on every day. This is one of the most critical elements of flooring for most homeowners. While the building’s framework must be considered, the final product’s visual appeal and tactile experience depend only on the floor. Carpet, ceramic tile, wood planks, wood parquet, vinyl sheet, and vinyl tile are the most often used floor coverings.


Vinyl sheet flooring, often known as linoleum, is frequently used in domestic settings like the kitchen, bathroom, laundry room, and foyer. This flooring is made of a vinyl composite with a coating on top, and it comes in a wide variety of colors, textures, and patterns in 12-foot-wide sheets of varied lengths. The vinyl is attached to a covering laid over the subfloor (often 4′ × 4′ sheets of mahogany or particle core). It is also compatible with basements and other locations with concrete floors. While the width of a room is more than 12 feet, especially while going under a doorway, it is common practice to join two sheets together. Sheet vinyl is a fantastic choice for flooring in damp locations like around sinks and tubs, and entryways. It lasts a long time and requires little upkeep. One of the least expensive flooring options is linoleum.


Vinyl tile is another water-resistant flooring option. It is often produced like sheet vinyl, except it is far more rigid and typically sold in units measuring 12 inches by 12 inches. Installation is relatively similar, albeit it does call for experienced professionals. If you want your tiles to be uniform in width from wall to wall, have the tile installer begin in the center of the room. The joints are less likely to come apart over vast areas, making this form of flooring preferable to sheet vinyl. This is why it is common in institutional settings, where spacious rooms are the norm. The same simplicity of installation applies when laying vinyl tile directly on concrete. It shares the water resistance of vinyl sheets and is, therefore, typically used in high-moisture parts of a structure. Tile is one of the cheapest options for a finished floor because it is durable, simple to maintain, and easy to clean.


Ceramic tile is one of the most long-lasting options, and it is frequently used in entryways due to its resistance to scuffing from sand and water accumulation. However, homeowners typically exclude bathrooms and kitchens from receiving this floor treatment because of the expensive installation expense. Standard sizes for ceramic tiles are 4 inches, 6 inches, 8 inches, and 12 inches square. There are also interlocking pieces available. They can be put into a thin mortar bed (called “thinset adhesive”), which functions like glue, or into a heavyset bed of 1-1/2″ regular mortar base, the latter of which is the more common procedure. To prevent tiles or grout from cracking; the floor must be strengthened before ceramic tile may be laid. The term “cement board” refers to a substance commonly used by installers that resembles drywall but is comprised of glass fibers and cement. Ensure your tile installer will guarantee against tiles cracking or lifting in the future. Although low-maintenance, homeowners often regret using high-gloss tiles in their bathrooms because of the danger of slipping on wet tiles.


The use of wood strips for flooring is one of the earliest methods that is still widely used today. It is installed by nailing or gluing interlocking wood strips to the subfloor. In many cases, the strips will already be finished without additional sealants or varnishes. This flooring option is not only costly but also requires a significant amount of time and effort to install. The end product, however, is a warm, long-lasting floor that needs hardly any care or repair. Wood strip flooring greatly diminishes the bed’s deflection (or “bounce”), making the base sturdy.

The most popular type of wood flooring is parquet tile. Simply put, they are constructed from square pieces of wood that are locked together using glue and metal wires. They typically measure 6″x6″ or 12″x12″ and have a thickness of about 1/4″. They are adhered directly to the subfloor and are robust enough to accommodate minor imperfections. Prefinished wood is low-maintenance and convenient. If you’re looking for a warm, long-lasting floor that won’t break the bank, consider a parquet floor instead of strip flooring.


Carpet is by far the most popular option for domestic flooring. It’s available in a rainbow of hues and finishes. The carpet comprises protruding fibers woven or bonded onto a foam or jute backing. Carpets are made much more comfortable to walk on with an underpad of pressed foam inserted below it or with the support made an integrated part of the carpet. The carpet can be adhered to the subfloor using carpet glue or tacked down using carpet tacks around the edges. A high-quality carpet will have a tight weave that conceals the backing when cut. Contractors looking to cut expenses may pair a high-quality underlay with a cheaper carpet. This gives the carpet’s plush feel and a long lifespan without breaking the bank for the average homeowner.


Manager Julian Arhire works for, a supplier of HVAC products such as Honeywell, Johnson Controls, Robertshaw, Jandy, Grundfos, Armstrong, and more. The company’s website, located at, lists more than 35 thousand of these items.

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