Troubleshooting
Made simple with out a design
At
the Bottom of the Foundation Wall Water or moisture on the top of Bottom
Wall Plate
and/or
high humidity in the basement.
Causes:
a. No Sump.
b. No or
too little gravel under the floor or under the footing plate or floor.
c. There
is something damming the water under the floor or under the footing
plate.
d. The Vapor
Barrier has been extended under the footing plate.
e. The Vapor
Barrier has not been cut off at the bottom of the footing plate, but
is instead extended into the gravel.
f. The Vapor
Barrier has been left off the Wall or omitted under the floor.
g. The bottom
of the sump has not been perforated or open to the gravel.
h. The sump
is not drained to a positive drain (by gravity or pump).
i. The sump
is not surrounded with at least 4 inches of gravel.
Foundation
wall sinks out of level at any point along the foundation wall.
Causes:
a. The axial
load is too heavy for the size of the footing plate.
b. There
is not enough gravel depth or width under the footing plate.
c. There
is too much building weight for the gravel depth under the footing plate
(gravel shear).
note this can happen only with undersize footing plates.
d. The footing
plate is too wide giving rise too induced tension. (oversize footing
plates)
e. Plywood
stiffener is too thin.
f. Plywood
stiffener face grain is not perpendicular to footing plate grain.
g. Plywood
or concrete concentrated load pad is missing or too small for the point
load.
h. The load
pad is not thick enough for the concentrated load.
i. If a plywood
pad, the adjacent pieces are not perpendicular to each other.
j. If a plywood
pad, the adjacent pieces are not glued together.
k. The footing
plate is plywood, the adjacent pieces are not perpendicular only when
required,
are not enough layers thick, are too wide, or are not glued together
as required by some
designs.
L. The footing
plates has been installed on a mixture of stone and snow. This will
cause the house
to sink when the temperture warm up. The
Installer of the footing plates must check for this condition
before installing the footing plates. A snow and stone mixture will
be below 3000 lbs per sq. ft.
A 3000 lbs. per sq. ft. stone footing is required by the pwf design.
The
foundation wall is bowed, out of plumb, or deflecting inward.
Causes:
a. There
is not enough bearing against the floor by the bottom edge of the studs.
b. The grade
for the species used for studs is too low.
c. The spacing
of the studs is too great.
d. Insufficient
number and/or size and diameter of nails used to nail bottom top plate
to studs.
e. The grade
for the species used for top plates are too low.
f. Nail spacing
is too far apart and/or size and diameter of nails used to nail the
two top plates
together.
g. Nail spacing
is too far apart and/or size and diameter of nails used to nail band
joists to top
plates.
h. Floor
joists not adequately attached to the band and the top plates (this
may be done with pwf
framing straps, joist angles, or joist hangers---The number of nails,
size, and diameter is
significant for each type of framing anchor).
i. Shear
wall(s) may be needed.
j. The length
of the shear wall(s) may be too short.
k. The nail
spacing at the plywood panel edges of the shear wall(s) may be too far
apart at the
plywood panel edges, and/or the nails are the incorrect length or diameter.
l. Horizontal
blocking may be left out at a horizontal plywood joint in the shear
wall.
m. Holes
were drilled in the tension half of the stud or near the point of maximum
moment.
n. At end
walls where the floor joists run parallel to the foundation wall, blocking
between the 1st,
2nd, etc. interior joist space(s) may have been left out or removed
for ducts, pipes, wires ,etc.
The block spacing is significant.
o. In all
blocked joist spaces the minimum joist spaces must be at least as wide
as the blocks
are high.
p. The sub-floor
above the foundation may not have been nailed to the 1st, 2nd,etc. interior
joists
at the correct nail spacing; or the correct number of nails were not
used to nail the sub-floor
to the blocks; or the nails are not the correct length or diameter.
q. The sub-floor
is not a rated sheathing.
r. When
a stairwell or other opening is in the floor-ceiling diaphragm, adjacent
to and less than
4 feet from a foundation wall with a backfill, the top plates of the
wall become a horizontal
beam. Depending on conditions, the beam is constructed by adding plates
to the top and
thru-bolting all the plates together. The lateral load on the beam is
blocked into the
floor/ceiling diaphragm through headers to the inside of the opening.
If this is not done
correctly the top of the foundation wall will deflect into the opening.
The grade, species, and
size of the top plates are significant in determining the number of
pieces to us for the beam.
The size of the bolts are important in order to determine the spacing
of the bolts. All bolts
used in wood foundations should always be hex-head machine bolts with
washers. (Never
use carriage bolts).
The
wood basement wood floor is up-lifting or sliding or sinking.
Causes:
a. Uplifting: The lateral soil loads at the bottom of opposite
foundation walls are
forcing the wood floor to rise near the center. A short kneewall under
the floor joists and
connected to the floor joists will correct this. Also, bearing walls,
shear walls, partitions, or
posts on top of the floor will do the same thing.
b. Sliding:
This can occur when a high backfill is opposite a walkout wall. Sliding
can occur if there
is no frost wall or anchor wall under the walkout wall; or if the wood
floor is not adequately
connected to the top of the frost wall. Nailing patterns become significant
at the bottom of the
walkout wall where it connects to the frost wall.
c. Sinking:
This occurs when the spacing between the sleepers is too wide for the
width of the
floor joists or floor joist spacing, or if the sleepers themselves are
too narrow in width to
adequately transfer the floor load to the gravel and ultimately to the
bearing soil; or if there are
no sleepers and the floor joists rest directly on the gravel under the
floor.
d. Uplifting
near walls: The plywood floor system has not been cut back 1/4"
away from all wall
studs.
e. Center
barring wall: Walls are not supported by the correct size tee under
the wall.
f. The
footings, sleepers and support tees are installed on a mixture of
stone and snow. This mixture
will not support the axial load to the bearing soil.
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