Some houses have the shiplap on a 45.
Floating floor have to be perpendicular to floor joidts.
First renail the existing plywood subfloor so that the old nails are tight and add new nails to achieve a maximum nail spacing of 6 inches.
Hardwood flooring is to be run perpendicular to the joists for structural integrity of the flooring system to prevent rolling or waviness between the joists over time.
This provides added strength to the floor and helps cut down on bowing in the laminate.
In these cases the conservative choice is to go perpendicular across the floor joists and allow them to support the new floor as well as the sub floor.
A flooring contractor howard brickman responds.
If the subfloor is stiff enough there is no reason why solid nail down strip flooring can t be run parallel to the joists.
If the subfloor is plywood of marginal quality then the finish floor should be perpendicular to the joists to stiffen the overall assembly.
Generally floor or ceiling joists run parallel to the rafters.
Just make sure the subfloor is flat and the proper thickness e g.
Plank should be stiff enough to span the joists with no problem.
Installing them parallel creates the possibility that the floor will sag.
That said some times it s not possible to do this.
If you go parallel to the joists you may end up with areas of flooring that aren t fully supported.
Since the floor joists typically attach perpendicular to the rim joists and roof rafters typically bear perpendicularly to the rim joists as well then the joists and rafters are typically parallel.
Flooring experts recommend installing flooring boards perpendicular to the floor joists in a house with a plywood subfloor.
If you have an older house with a shiplap floor the shiplap is perpendicular to the joists so the flooring is parallel to the joists.
Most directions recommend running laminate flooring perpendicular to floor joists.