Decks.com. Nailing a BeamLearn how to nail a beam together. How many nails should you use? What type of nails should you use? ... When securing 2 or more dimensional wood boards together to form a beam you will need to use the proper number and size nails to create a solid member. A 2x10 Beam should use a minimum of (4) - 3 nails fastened in a vertical pattern from both sides of the beam every 16 on center. Be on the safe side when in doubt and use extra nails, having too few nails can result in ...