Floor panels most often utilize I-joists for structure, with the grade, thickness, and spacing depending on the requirements of the project engineer. We use TJI, BCI, and LPI I-joists of varying grades, and depending on material cost and availability at the time of production. Floor panels are typically designed to be platform-framed, with a 1 3/4″ LVL beam of appropriate height providing the structure at the rim, though sometimes it is smarter to use hangers which can be pre-installed in the panels in the shop, and fastened on site to a ledger. Floor panels always use tongue and groove 3/4″ plywood, glued and screwed. While less common, sometimes floor panels utilize dimensional lumber, incorporate decorative wood on the underside, or offer a hybrid between the two types of panels below, incorporating blocking to keep exterior sections insulated (for example, under a deck), while the interior portion is left uninsulated.
We offer two primary types of floor panels:
Uninsulated floor panels: The simplest panel, typically built with dimensional lumber, I-joists, and LVL rim boards, with a layer of glued and screwed, tongue-and-groove plywood on top.
Insulated floor panels: The same panel as above, but with a membrane or plywood bottom that holds in a cavity of dense-packed cellulose (recycled newspaper) insulation, installed in the shop. These panels typically provide structure while also providing sound insulation and/or heat resistance insulation for unconditioned attics.
Clients often ask if we deliver the first floor panel to go on top of foundation stem walls, and the answer is typically no, due to needs for both plumbing and electrical work in this typically insulated panel, and the need to have foundations backfilled before equipment can be brought in to install wall, additional floor, and roof panels. Therefore the majority of our floor panels are either mid-floor panels or ceiling panels under unconditioned attics.