The first step in installing tongue and groove
decking over the floor joists is to snap a chalk
line. This gives you a straight line to follow as
you install the plywood. Snap this line at 48 ¼
inches in off the edge of the rim joist, or outside
edge. This ensures that in the course of
installation the plywood (which is 48" wide) will
not hang over the edge of the rim joist. It doesn't
matter whether you start in the front or back of
the house. For best results start with the longest
run without a jog in or out in the foundation.
After you have snapped your line determine which
joist the first sheet of plywood will break on. If
the joists are 16 inches on center from the end of
the building the edge of the plywood should split
the joist at 8 feet. Sometimes the roof layout
determines the floor joist layout. This is usually
the case when the roof is a hip roof. In this
instance, start with the joist that will allow the
plywood to cover all the joists, even if it hangs
over the edge of the first joist. It will be cut
After you have determined where to start, apply
adhesive to the top edge of the joists. Apply no
more than 48 inches, the width of the plywood. Lay
the first sheet in the glue with the groove edge on
the chalk line. While holding the sheet to the
line, nail the leading edge of the plywood to the
rim joist so it splits the joist.
Put nails in the rim joist where the floor joists
are nailed into it. When nailing off the field,
these nails can be used as a guide to find the
Nail the groove edge. On the leading edge, move the
joist as necessary so the edge of the plywood
splits the joist. Once you have the joist aligned
where you want it, nail the plywood to it.
Hook the tape measure to the leading edge of the
joist you just nailed and pull it along the edge of
the plywood. Mark 16 inches on centers on the
plywood and pull the leading edge of the joists to
this mark and nail them. This will help keep the
joists in line and will help make sure future
course of plywood breaks on 16 inches centers no
matter which joist you start with.
Glue the joists for the next sheet. Butt the next
sheet to the one previously installed while making
sure to hold it to the chalk line and nail the
groove edge corner. Nail it to the rim joist just
like the first sheet. Move the joist so the plywood
splits it. Hook that joist with your tape, mark
centers and move the joists to the lines.
Continue laying the plywood in this fashion to the
other end of the building.
You’re now ready for the next course of plywood. If
you have started with a full 96 inch sheet of
plywood on the first course start the second course
with a 48 inch piece. This works great if the
building length is in increments of 4 feet. This
isn't always the case. If the building is an odd
length you can usually use your ending cutoff to
start the next course. Stagger the joints at a
minimum of 32 inches apart.
the next course by gluing the joists the same way
you did the first course.
the sheet on its tongue edge next to the groove
edge of the sheet you are standing on. Make sure
its butt edge is lined up on the joist it is
breaking on and let it fall into the glue. As it
hits the glued up joists step on it and try to pull
it in with your foot. Only under the right
conditions will the tongue go completely into the
groove. Sometimes the sheet can be jumped into the
groove. This involves standing on the sheet and
jump with force towards the sheets in the previous
row. In most cases it takes a sledgehammer and a
piece of 2x4 as a beater block to push the sheets
together. The block keeps the groove edge from
getting damaged by the sledge hammer.
the piece is in place, nail the tongue edge making
sure the leading edge is breaking on a joist. Move
the joist so the groove edge breaks on the joist.
Pull 16 inches centers from that joist, mark the
plywood, move the joists if necessary, and nail
have the plywood hanging over the end of the deck.
After all the plywood is in place, snap a line from
one corner to the other and cut off the overhanging
That’s all there is to installing tongue and grove