How much extra flooring should I buy?
10% for straight installs, 15% for diagonal or herringbone, and 20% for rooms with many angles. Keep one spare box for future repairs — dye lots change.
Calculate how much flooring you need for any room. Supports hardwood, laminate, tile, and vinyl with waste factor and cost estimation.
Boxes needed = ceil(room area × (1 + waste %) ÷ coverage per box). Underlayment rolls = area ÷ roll coverage.
A 300 sq ft room with 10% waste needs 330 sq ft of material. At 23.8 sq ft per box that is 14 boxes, and 15 if you are laying on the diagonal.
10% for straight installs, 15% for diagonal or herringbone, and 20% for rooms with many angles. Keep one spare box for future repairs — dye lots change.
Usually yes for laminate and engineered wood, unless the planks have it attached. Over concrete you also need a vapour barrier of 6-mil or better.
Along the longest wall or towards the main light source. This visually lengthens the room and hides seams best.