I agree with Mac and use solid whenever I can get the right material. I only use stave core when working with unstable or extremely knotty material. Doors have been built solid for many centuries.
We used Timberstrand for cores on an interior door job many years ago and had a couple callbacks where the 1/8¡± skin cracked. This material has little movement and you need thin skins to avoid cracking. The contractor commented that my quality must be out the door if using OSB for cores. Never used it again. The local hardwood dealers sell Timberstrand specifically made for doors and supposedly has low MC and stored in doors. National Wood sells a LVL core material made for doors. It is made from fir and the grain is vertical orientation compared to construction LVL that have flat grain and usually high moisture content. I do use this material occasionally for difficult material. Works well for barnwood doors.
Recently replaced some doors on a historic commercial building. Doors were over 100 years old and actually not in terrible condition. One was solid pine with high exposure and the other stave core construction that was under a 6¡¯ overhang. The solid door was in a lot better condition than the sat e core one. The cores had telegraphed through and much cracking of the 1/8¡± skins. I built the new doors out of 10/4 solid Sipo Mahogany, first picture. Second picture is a barnwood door with the LVL core. Third picture is 3 layer lamination for a 68mm thick euro door in knotty white oak. This is a good construction for these thick doors where material needs to be laminated. With this construction there are no glue lines to the weather compared to an exterior door with 1/8¡± or thicker skins.
