Young Blonde Girl In The Room With A Chair Posing At The Door

- Hollow-core - Often consists of a lattice or honeycomb made of corrugated cardboard, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core flush doors are commonly used as interior doors.
+ Lock block - A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
- Stave-core - Consists of wooden slats stacked upon one another in a manner similar to a plank & batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
- Solid-core - Can consist of low-density particle board or foam used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation and strength.