To achieve the 16 inch depth we wanted for insulation and an air space under the sheathing we used open web parallel chord trusses as the rafters.
Insulating open web floor trusses.
4d extend insulation into joist space to reduce air flows.
It also allowed us to create a basement ceiling with minimal bulkheads except where load bearing beams are installed.
The joists allowed us to reduce the boxes and bulkhead to hide ducting to almost zero with the exception of inside a main floor closet and the main floor powder room.
Gaps in open web truss or engineered floor joist systems may be difficult to address with this type of insulation.
Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances.
Open web floor truss insulation options hi bodo and welcome to the forum.
Open web floor trusses.
These trusses typically used as joists have diagonal bracing or struts and are made in quebec by open joist triforce.
I ll have to do some searching on the paper against the bottom of the floor if you go this direction but one of the experts in the field stated that paper to the warm side of a home was not intended for basements.
Of the conditioned space above.
Open web joist chase opening.
When the basement or crawl space has vents installed insulating joist bays.
It is sprayed directly to the underside of the sub floor and adheres upon impact.
I have these in my home and i use the space for extra storage as you can see in the picture.
It must be cut to fit snug between floor joists.
Spray foam insulation expands upon exiting the foam gun.
Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below.
4b slab floors built directly on the ground.