Quick Answer: I joists typically run $2.50 to $11 per linear foot as of 2026, depending on depth, flange grade, length, and manufacturer. Most residential work lands between $3 and $7 per LF for common 9.5 inch and 11.875 inch depths. Prices vary by supplier, region, quantity, and grade, and they move with the lumber market, so use these ranges as a starting point and get current quotes for your bid date.
What an I Joist Actually Is
An I joist is an engineered wood framing member shaped like a capital I. The top and bottom flanges are solid dimensional lumber, usually LVL (laminated veneer lumber) or MSR (machine stress rated) spruce, and the web between them is OSB (oriented strand board) glued and compressed into a vertical sheet. That shape gives the joist a lot of depth and stiffness for very little wood weight, which is why it spans farther than solid sawn lumber of the same depth and resists the warping, twisting, and checking that plagues dimensional joists. You will see them called by brand names like TJI (Weyerhaeuser), Boise Cascade BCI, and LP SolidStart, and those brands are not interchangeable on a set of plans. Architects and engineers specify a specific product or an equivalent, so your takeoff has to match the called out series.
What Drives the Price
Depth is the biggest single driver. A 9.5 inch TJI 110 at 16 inch on center might price at $2.50 to $4 per LF, while a 16 inch TJI 360 for a long clear span can hit $8 to $11 per LF. Flange grade matters too: LVL flanges cost more than MSR but they carry more load and stretch the allowable span, which often lets you drop a joist or a bearing line and save more than the unit price difference. Length affects price because long pieces (over 32 feet) are harder to ship and handle, and suppliers charge a premium or force you into a splice. Manufacturer and series drive the number as much as size, because each brand has its own load tables and the engineer often calls out a single series. Region matters through freight and local demand, and volume moves the price a full tier when you buy a truckload instead of a bundle.
Typical Price Ranges by Type
- 9.5 inch depth, entry series (TJI 110, BCI 5000s): $2.50 to $4.00 per LF, used for short spans in residential floor and roof framing.
- 11.875 inch depth, mid series (TJI 210, BCI 60s): $3.50 to $6.00 per LF, the workhorse for most single family floors at 16 inch on center.
- 14 inch depth, heavy series (TJI 360, BCI 90s): $5.50 to $8.50 per LF, used for longer spans or heavier floor loads.
- 16 inch depth, heavy series (TJI 560, BCI 90s): $7.00 to $11.00 per LF, long clear spans and tile floors where deflection is critical.
- Rim board, matching OSB rim: $3.00 to $6.00 per LF, often sold per linear foot of joist or as 8 foot and 12 foot pieces.
- Allowable hole web joists, point load joists: 10 percent to 20 percent premium over the base series for the same depth.
How to Take Off I Joists for a Bid
Count joists by depth and series, then multiply by the run length at the specified on center spacing. Read the framing plan, not the floor area, because a 16 inch on center layout has a different joist count than 19.2 inch or 24 inch on center, and a switch from one to the other changes your LF and your price. Add rim board to the same takeoff at the perimeter of the framed area. Apply a 5 percent waste factor for cuts, defects, and short offcuts you cannot reuse, and round up to the bundle count the supplier sells in. Most I joists ship in bundles of 5 to 12 pieces, and partial bundles either are not sold or carry a cut charge, so rounding up matters. Carry the joist hangers, squash blocks, rim board clips, and joist tape into the same takeoff, because those accessories can add $0.40 to $1.20 per LF if the detail calls them out.
How to Buy Smarter
- Get three supplier quotes for the same series and depth. Prices commonly swing 15 to 30 percent between yards on the same bid date.
- Ask for a truckload price if your total LF is over 4,000. The volume break can drop your unit cost a full tier.
- Lock quotes for 30 to 60 days on longer bids. I joists track the OSB and lumber commodity index, and a two month bid window can move your number 8 to 15 percent.
- Confirm the manufacturer before you quote. A TJI 210 and a BCI 60s are close in capacity but the engineer often calls out one, and substituting without an approved submittal triggers a change order.
- Buy rim board from the same supplier and the same brand. Mixed brands on a rim line is a common inspection flag.
Where Estimators Get It Wrong
The biggest miss is treating I joists like dimensional lumber. You cannot freely swap depths and series the way you swap a 2x10 for a 2x12, because the load tables and the web hole patterns are product specific. Estimators also forget the accessories: hangers, squash blocks, rim board, and joist tape are part of the system, and leaving them out of the takeoff underbids the floor package. A second common miss is ignoring the web hole rules. Every manufacturer publishes where you can and cannot cut holes in the web, and a floor that needs heavy runs of plumbing or HVAC often has to step up to a deeper joist to keep the holes inside the allowed zones, which raises the unit price. Finally, estimators quote from last quarter's price list and assume it holds. I joists move with the OSB and lumber market, and a six month old quote can be off by 10 percent or more in a volatile year.
Putting It Together
For a typical residential floor, plan on $3 to $7 per LF for the joist, another $3 to $6 per LF for matching rim board, and $0.40 to $1.20 per LF for hangers, blocks, and tape. Take off by depth and series, add 5 percent waste, round to the bundle, and get three quotes dated to the bid. Treat the I joist as a system, not a stick, and your floor package will land close to budget and pass inspection the first time.