Buy Floor Joists -

: The traditional choice made from solid lumber like Douglas Fir or Southern Pine . Best for : Simple residential projects and shorter spans.

: Eliminates the need for drilling or cutting holes for utilities. buy floor joists

The "span" is the distance between supporting walls or beams. Joist size significantly impacts how far they can safely reach. The I-joist Handbook - Masonite Beams : The traditional choice made from solid lumber