floor joist bridging is critical to the structural strength of a floor, as shown in figure 1. proper bridging distributes the load on the floor to other joists and over time prevents floors from sagging and squeaking do to floor joists twisting and warping. yet it is not uncommon to find bridging not properly installed or missing all together.
*designed properly, engineered joists will make for a stiffer floor. a common problem is using the span tables too literally. the listingis the maximum allowable spans. just as most builders would not try and use the minimum size allowed 2x joist to acheive a stiff floor, you should not push the limits of engineered joists.
joists are horizontal supports that span from wall to wall, wall to beam, or beam to beam. several popular options include solid lumber, lvl, wood i-beams, steel joists and open web floor trusses. lets examine three of these materials. solid lumber joists. traditional solid lumber joists are still very common.
i've been asked this question often, should i use a solid rim joist or block i floor joist. a solid rim joist is easier to install, but doesn't provide you with enough support to prevent your
after several centuries of service, floor joists in older homes may sag or crack. long spans of joists in newer homes may wobble or bounce from foot traffic. as incremental parts of a building's
this article provides step-by-step instructions and pictures on how to make structural repairs by sistering floor joists alongside weak joists. if you have sagging, cracked or twisted joists, which can happen in older houses, this project will provide the extra support the floor needs.
leave outside joists for last and install blocking from underneath. on a low deck, where blocking cannot be installed from underneath, stretch a string from the house to the outside edge along each outside joint for a reference. cut blocking to fit so that joist stays aligned with the string.
these days, many new floors are framed with i-joists, a type of engineered lumber that's a fraction of the weight of conventional lumber and capable of spanning greater distances. still, if asked to span too great a distance, i-joists will bounce. as a rule, the same kinds of methods that take the bounce out of solid-lumber floors work for i
properly insulating and air-sealing rim joists band joists takes patience, so some builders simply stuff in some fiberglass and walk away. if you're working on an unfinished basement, you can properly insulate the rim joists in just two or three hours.
different from slanting/sloping floors are those that sag or have dips. for instance, you may have a dining room floor that, end to end is level, but between those two points are various sags and dips. your foundation may not be the problem. instead, it may be an issue with joists and beams below your floor that require shoring up.
whether your home is new or old, it is sometimes necessary to install floor joist bracing in order to eliminate squeaking and deflection in the flooring itself. bracing will stiffen a floor system, prevent floor joists from twisting, and increase overall stability.however, there are actually two types of floor joist bracing commonly used: cross bracing and solid blocking.
floor joists. a floors framework is made up mostly of wooden joists that run parallel to one another at regular intervals. floor joists are typically 2 by 8s, 2 by 10s, or 2 by 12s; ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home. some newer homes have manufactured, i beam shaped joists.
engineered to provide strength and consistency, weyerhaeusers trus joist tji joists are one of the most fundamental components of a solid, high-performance floor system. and with their light weight and long lengths, tji joists are faster and easier to install than traditional framing, which can save time and money.
the joists immediately under the load deflect substantially before the straps are tensioned and start spreading weight to other joists. properly installed wood x bridging tightens as the joists shrink, to the degree that i've seen the bottom of the joists get a slight crook in them from the bridging.
lp solidstart i-joist benefits. lp solidstart i-joists are more versatile than open web floor trusses, and more uniform and dimensionally stable than lumber. they can be trimmed on-site, and long lengths allow ceilings and floors to be designed with fewer pieces, saving installation time.
how to properly splice a joist or rafter . we'll begin our discussion by reminding everyone that carpenters have been splicing wood together for thousands of years. it's one of the things carpenters do best but still there are those who say that this is the purvue of an engineer and no one else.
coupled with adequate joist support, a subfloor provides the structure that assures your floor will be solid, level and properly supported. over concrete, subfloors can keep a room warmer and drier and more livable. if you have an opportunity to specify your subfloor materials, it's well worthwhile to choose the best you can find.
wide flanges provide a larger gluing and nailing surface for floor and roof sheathing. openings can be strategically cut in the i-joist web to allow for wiring, ductwork, and plumbing. one i-joist can do the work of two or more solid joists. between 15% and 20% of i-joists are now being built with solid-lumber flanges.
is there an opinion about about metal bridging vs. wood blocking for floor joists? i have a near 10' run of 2x8 floor joists that i intend to insulate between with mineral wool. would the metal bridging be better for getting the batts closer to each other or is it inferior for some other performance reason? i do not plan on running, wires, duct, or pipe in the joist bays.
the electrician drilled 3 3/4' holes an inch or so apart through a series of 2x10 joists. there is about 1-1/2' from the bottom of the holes to the bottom of the joist. there is more than one set of three holes and the distance from the end of the joists varies but they all appear to be in the middle third of the length of the joists.
joist to girder attachments are normally supported with joist hangers, easyclip e-series or s-series support clips. web stiffeners may be required at supports and other point loads. solid blocking and strap bridging is required to properly brace the floor assembly. precut to exacting sizes and readily available
properly sistering floor joists is very important and should not be rushed to save time. since this is a repair of a faulty or damaged floor joist, it is imperative to do this project correctly, and there are a few big mistakes to avoid. be prepared to get a little dirty, but rest in the fact that
rim joist blocking alternative. on the side of the house close to the existing townhome, we were unable to install a rim joist because it would be impossible to nail the board in place. there is no access to the outside of the wall . to achieve a similar benefit, we installed wood i joist blocking between the existing joists.
if your home is built on expansive soil and, thus, subject to regular movement, a screw jack can be used in lieu of solid wood posts between the concrete piers in the clspace and the girders that support the floor joists. a screw jack is a metal support post that can be adjusted to level
bridging allows each joist to share weight with its neighbors and can cut deflectionhow much the joists flexby half. even if your floor already has a row of bridging running down the center, you can stiffen it substantially by adding two more rows. the catch, of course, is that the bouncy floor joists must be accessible from below.
set the floor joists. set each of the boards you cut for the main floor joists in place along the lip of the sill plate, making sure they're properly aligned with the markings you made. when measured, cut, and placed correctly, the main floor joists should fit flush against the rim joists.
re: cross bracing on i joists dave-nice post. your thoughts and experiences are very similar to my own. i don't spec floor systems' details, such as joist size, spacing, series, but we're looking at a job that has very lousy dings/specs, in which we will be making recommendations along the way.