I have a dryer vent that exits the house wall through two wooden beams. The vent is built using two corner rigid pieces and one long rigid aluminum piece. The long rigid piece is the one that passes through the two wooden beams. Both beams are touching the rigid duct. Beyond that there is exterior brick wall.
Is it safe if the aluminum touches the wooden beams? I know that rigid is the safest in terms of not gathering lint and containing a fire in it.