Joists in home construction are usually made with 2 by 10 or 2 by 12 lumber.
Floor depth light.
The bulk of the floor s thickness comes from the joists which are the horizontal beams that carry the floor s weight.
In this zone the intensity of light rapidly dissipates as depth increases.
Also light shelves should be installed high enough to be out of hanging reach and to avoid a feeling of claustrophobia.
The type of flooring you choose will add some height to the floor.
The depth of light shelf should be equal to the clerestory or transom above it and no deeper than 30 inches.
Hardwood floors and standard carpet with pad add about 3 4 inch to the floor height.
Vinyl flooring is usually the thinnest choice for floors and 1 8 inch vinyl installed over 1 4 inch underlayment will add only 3 8 inch to the floor height.
Medium loads if the garage is used for average sized vehicles and or medium to heavy trucks the concrete needs to be six inches thick.
From south to north has been shown to be viable for daylighting.
The zone between 200 meters 656 feet and 1 000 meters 3 280 feet is usually referred to as the twilight zone but is officially the dysphotic zone.
Only a small amount of light penetrates beyond this depth.
Light shelves also have size limits.
A maximum facade facing due south is the optimal orientation.