CAUSES and CURES (FIRST AIDE SUGGESTIONS of common wood floor problems
and concerns) QUICK FIND INDEX:
CROWNING - BUCKLING
"Washboard". Across the width of one piece of the flooring
material, the edges are high, the center is lower. Generally develops
Moisture imbalance through the thickness is the only cause. The
material was manufactured flat and was flat when installed. Job site
or occupant provided moisture is greater on the bottom of the piece
than on the top. Prove it with your moisture meter. Find the source of
moisture and eliminate it. Common moisture sources and their
corrections are: Airborne (Relative Humidity) - dehumidify air space
or (lack of during heating season humidify air space); wet basement -
ventilate, dehumidify; crawlspace groundcover/vents, add exhaust fan
on timer; lot topography - french drain to remove; rain handling
provisions - correct to drain away from house; excessive lawn/garden
moisture - reduce/waterproof foundation; leaks plumbing, roof, doors -
fix; don't hose patio; maintenance; correct capillary through slab -
install barrier, french drain, drain tiles. In kitchens, the
dishwasher and ice maker are notorious leakers.
Expansion is also the result of site moisture and may have moved the
floor tight to vertical surfaces. If so, remove flooring along the
wall, or saw cut, to relieve pressure.
Allow time. Time for the corrections to take effect - to permit the
floor to improve on its own. It may become acceptable . After
stabilized, sand flat and finish. Cost of corrections should be for
owner or builder to cover.
"CROWNING", or the center of the piece of flooring (across
its width) is high, the edges are lower.
While moisture imbalance might be the cause (by excessive moisture
introduced on the finish side of the floor; i.e. water used in
maintenance, plumbing leaks overhead sprinkler system), it is more
likely that the floor was cupped (problem #I) and sanded flat thus
removing the outer edges, the sanding having been done at the wrong
time, i.e., before corrections were made and before the floor
flattened on its own.
After the floor has stabilized following corrections, sand flat and
finish. Note: Some slight cup and/or crown can and should be
tolerated. It is common in wood floors, especially in wider planks. It
is, in many cases, seasonal in its occurrence and can be minimized
with lighting and furniture placement, by using beveled products and
by other than high gloss finish
"BUCKLING", "tented", "ballooning"
floors. Pieces of the flooring are no longer in contact with the
Generally an extreme moisture problem. See Problem #1 for sources and
corrections. Inadequate expansion space, even "net fit"
(installer error) prevents normal expansion. On nailed products,
insufficient nailing, incorrect nails, incorrect sub floor
construction. On glue down product, incorrect mastic, insufficient
mastic, wrong trowel used, inadequate mastic transfer, sub floor
separation, sub floor contamination.
If caught early, spot repair/replacement may be possible. In many
cases, however, pull, correct, and relay/replace is more practical.
-SEPARATION BETWEEN INDIVIDUAL FLOORING PIECES- ABNORMAL CRACKS -
LOOSE, NOISY, SQUEAKY FLOOR- UNEVENNESS
NORMAL CRACKS - SEPARATION BETWEEN
INDIVIDUAL FLOORING PIECES:
Mother Nature. Dryness. As moisture caused some earlier problems 1,
the loss of moisture results in the most frequent reason for shrinkage
of individual pieces and cracks. Should a floor have been exposed to
problems 1, 2 & 3, then afterwards, "dried out", cracks
will develop. If subjected to extreme moisture, the edges of the wood
(a vegetable made up of cells), can crush, and subsequent drying and
shrinkage can present larger than normal cracks. Square edge
(un-beveled) floors show cracks more than beveled. White, light,
pastel finished show cracks more than darker wood-tone finished
floors. Most cracks are seasonal - they show in dry months, or the
cold season when heating is required, and close during humid periods.
This type of separation and closing is considered rm 1. In solid 2
1/4" wide strip oak floors, dry time cracks may be the width of a
dimes' thickness (1/32"). Wider boards will have wider cracks
(and the reverse is true).
Add moisture to the air space during dry periods. A constant Relative
Humidity (RH) of 50% works in concert with the manufacture of wood
floors to provide stability in the floor. Live with normal cracks or
add humidity - its 'the owners' choice. Easy ways - boil a pan of
water on the stove, turn off bathroom exhaust fan, open dishwasher
after rinse cycle, a pan of water in furnace fan compartment, hang
laundry to dry in basement. Better yet, install humidifier to furnace
controlled by a humidistat set at 50% RH. In dry and warm climates,
add moisture (pan or humidifier) and run furnace "fan only".
ABNORMAL CRACKS: Abnormal cracks - larger than normal, cluster or
localized, end separation, not uniform and not general throughout, do
not close up during humid months.
Edge crush from prior exposure to extreme moisture, especially solid,
flat grain flooring (and may be general throughout). If surface coated
(such as polyurethane), edges of some adjacent pieces may be literally
"glued" together, or panelized, and shrinkage cracks
multiplied at the weakest points. (See note that follows) "Hot
Spots" in the undersurface such as poorly insulated heating
ducts, hot water plumbing lines, radiant heating system (if so, should
be laminated products only), the new "Instant Hot Water"
feature, register openings, heat from refrigerator motor, check nail
spacing with stud finder. With adhesive applied floors, early foot
traffic, incorrect adhesive, amount transferred or used (most noticed
in traffic pattern). 3/4" thick solid parquet with no return
control (cork) in expansion space, generally indicated by center of
the field is tight, with gaps around the walls. Note if there is a
pattern to the cracks, such as 4' X 4' or 4' X 8' indicating sub floor
change or weakness. Glued over sheet vinyl may show 6' cracks from
shrinkage or loose vinyl. Does the pattern of cracks convey a
relationship with foundation or slab cracks and/or settlement. Check
nail spacing on solid products take wood moisture content reading and
if it is within normal range for your market and the wood is
undersize, drying was improper prior to manufacture. If wood MC is
normal and wood is "on size" or over, the wood was wet prior
In addition to obvious corrections suggested under it cause"
(i.e., add insulation between heat ducts and sub floor for "hot
spots", pull, add adhesive, relay, adjust 3/4 parquet, add
expansion joint control, add cross bracing under weak sub floor),
attempt to elevate the relative humidity in the air space and after
sufficient time has passed to confirm that the problem has stabilized,
fill the cracks with the appropriate color-matched fill. Re-coat if
necessary. Last resort, pull and replace - note however, that if
corrections are not made, chances are that replacement will develop
the same problem. Note: When a floor shows "panelizing" and
a surface coat has been used, you might choose to sand then finish
with seal and wax, or if surface finish is required, use a sealer
first rather than the stronger finish directly on the new floor.
LOOSE, NOISY, SQUEAKY FLOOR, NOISY, SQUEAKY FLOOR
Inadequate nailing, flexing weak sub floor system, nailed over
particle board type sub floor. Check sub floor thickness and joist
direction. Insufficient or incorrect adhesive. Subjected to excess
moisture, excessive drying.
Add face nails, counter-sink&putty. Strengthen sub floor from
below. Inject adhesive or pull-add-relay. Lubricate squeaks with
graphite, wax, baby powder. Wedge sub floor up from joists.
UNEVENNESS-CAUSE:Wood joist system - sub floor warped and
loose, joists warped or fractured, support pillars settled, perimeter
foundation settlement.Concrete slab system - slab cracked and settled.
Correct, strengthen substructure, repair sub floor, splice joists, add
joists. Structural, failure is not the wood floor contractors domain
usually. Owner needs a general contractor for repairs prior to wood
Quality or"Grade"- knots, heavy color variation, out
of-square, surface defects.
CAUSE:Consumer expectations, incorrect
sampling, incorrect ordering, mistake by supplier, manufacturer,
installer error (should not have installed).
CURE:Pull and replace offending pieces.
Review samples with owner.
Excessive and Early wear
on finish - scratches, traffic pattern. Finish Peeling - bubbles,
blister - ROUGHNESS
CAUSE: Improper maintenance, grit,
water, strong soaps, dog toenails, chair legs.
CURE: Correct maintenance, especially
vacuum, not just broom sweep. Clip dog's nails, felt chair leg glides,
appropriate exterior walk-off mats to prevent grit, area rugs
especially in front of kitchen sinks. Re-coat if necessary - owner
Finish Peeling - bubbles, blister
CAUSE: Stain not dry. Excessive
burnishing. Early coats not dry. Skipped screening between coats.
Product incompatibility. Stain not sufficiently wiped leaving heavy
pigment on surface (is finish peeling from finish or wood?), improper
tack. Surface contaminated such as wax, oil soap maintenance.
CURE: If de-lamination from wood
surface, sand and refinish. If surface only, screen and re-coat.
Pet Stains CAUSE- (We all know the
CURE: For the most part minor pet stains will lessen or get lighter
with sanding. Repeated stains (the darker the deeper) will not sand
out. Several consideration must be given. 1 - Will the floors be
refinished ? If so, a light or medium colored stain can be use to help
"cover or lessen" the stains. Sometimes a
"painted" design on the floor will cover the stains, or the
use of area carpets over those stained areas. 2 - Removal and repair
will give BEST results, if time, and budget allowances are made.
CAUSE: Moisture from maintenance,
spills, constant source, condensation causing surface grain raise.
Poor sanding, edging, scraping. Contamination in finish during dry
CURE: Correct moisture source. Lightly
sand or screen. Re-coat.
- not right, changed
CAUSE: Customer expectation, poor
sampling, lighting over the floor and room colorings. In correct
maintenance including residue of cleaners, waxes, etc. (i.e., Oil
Soap). Wood itself changes color with age ("Patina").
Extreme hot sunlight through South/West facing windows. Color
different under rugs or low furniture from lack of exposure. Bleaching
is unpredictable - don't oversell expected results.
CURE: Compare with sample. Explain
lighting and colors. Remove residue and correct maintenance
procedures. Move rugs and colors will even out in time. Shade large
Dents - Yes, wood dents.
CAUSE: High heels. Pet nails, Dropped
heavy objects, metal tips on furniture legs. Unprotected rolling of
heavy appliances such as refrigerator or freezer.
CURE: Remove high heels or maintain
proper heel-tip protectors. Keep pet nails clipped. Provide large felt
or rubber protectors under heavy furniture legs. Roll heavy casters
over plywood protection only. For individual dents where wood fibers
are not broken, cover with a dampened cloth and press with an electric
iron to draw fibers up. Last resort sand and finish - owner pays.
CAUSE: Water from spills, water from
continual source leading to mildew (black) or decay (brown/white) or
alkali (white) or bleeding up of adhesive. Urine (dark) from pets, wet
diapers. Unprotected metal chair legs. Improper maintenance with water
or harsh chemicals. Traffic pattern wear. Excessive harsh sunlight
(wood looks starved near South or West facing windows). Light
deprivation under area rugs, large low furniture. Be sure to observe
if only one piece of flooring is affected, or does the stain continue
across adjacent pieces. Oil soap residue.
CURE: Correct water source, let dry.
Minimize sunlight. Relocate area rugs. Correct maintenance procedures
and products. Dark stains, lightly abrade surface with fine sandpaper,
feather out area, dampen cloth with 50/50 household bleach & water
and lay on stain for 30 minutes, remove, let dry, re-color if
necessary. Waxed floors, clean with renovator or paint thinner
(combustible) and re-wax. Whiteness/cloudy surface finish, clean and
buff. If all fails, screen and coat, sand and refinish, replace severe
First Aid for Surface
Most common burns can be treated with touch up kit (rub with steel
wool /sandpaper, stain as needed, touchup finish)
If burn is deeper, boards/pieces may have to be replaced
Chewing gum, crayons, wax
A plastic bag filled with ice on top of deposit until brittle enough
to crumble off. Clean area with cleaners made for urethane finishes
Greasy spots, Food
Cleaners made for urethane finishes (cleaning kit from your wood floor
Repair with touch-up kit from your wood floor retailer, "Endust"
on a soft cloth, wipe in direction of scratch will help bring back the
TO THE TOP
CAUSE:Termites-Identified by eating
corridors beneath surface which when weakened, the fragile surface
sags. The bugs are white or cream colored. Subterranean type build
sand tubes. Powder post Beetles identified by 1/ 16" diameter
perfect circle hole in surface of floor. Active infestation will show
clean bright wood in holes with fine talcum powder like dust piles
around the holes. Inactive holes are darkened, even show stain or
finish on walls of the hole. When in doubt, collect sample bugs,
consult exterminator, entomologist, or extension service, etc.
Structure must first be rid of active termites by professional
exterminator. Repair structural damage. Pull and replace damaged
floorboards, sand and refinish. Heavy infestation of powder post
beetle, handle as above. When powder post is occasional, few boards
especially in new floors, treat individual openings immediately with
insecticide (from hardware or garden shop) injected by syringe into
holes, or aerosol insect spray through a straw. Usually will not
disturb finish. Have owner watch for new evidence (dust piles) and
treat again. After 2-3 months holes may be filled. Termites will not
be associated with the flooring and costs will be the responsibility
of the owner. Powder post may be in new flooring materials.
Immediately on first report notify your floor supplier. Prompt action
by all will minimize costs involved. Check all surroundings for
infected wood molding, furniture (especially bamboo and antiques). If
old infestation is in other materials the owner must stand the costs
involved in floor repairs.
Wood Damage by
Wood damaged by subterranean termites is often not noticed because the
exterior surface usually must be removed to see the damage. However,
galleries can be detected by tapping the wood every few inches with
the handle of a screwdriver. Damaged wood sounds hollow, and the
screwdriver may even break through into the galleries. Subterranean
termite feeding follows the grain of the wood and only the soft
springwood is attacked. Unlike dry wood termites or other wood boring
insects, subterranean termites do not push wood particles or pellets
(fecal material) to the outside, but rather use it in the construction
of their tunnels. This debris, along with sand and soil particles, is
used as a form of plaster.
SUBTERRANEAN TERMITE PREVENTION AND
The best control of subterranean termites is prevention. The best time
to provide protection against termites is during the planning and
construction of a building. Prevention should include: 1-Removal of
all stumps, roots, wood, and similar materials from the building site
before construction is begun. 2 -Removal of all form boards and grade
stakes used in construction. 3-There should be no contact between the
building woodwork and the soil or fill. Exterior woodwork should be
located a minimum of 6 inches above ground and beams in crawl spaces
at least 18 inches above ground to provide ample space to make future
inspections. 4- Ventilation openings in foundations should be designed
to prevent dead air pockets and of sufficient size to assure frequent
changes of air - at least 2 sq. ft. to 25 running feet of outside
foundation wall. This helps keep the ground dry and unfavorable for
termites. 5- Thorough annual inspections should be conducted to
discover evidence of termite activity such as shelter tubes on
foundation surfaces, discarded wings or adult termites. 6- Any wood
that contacts the soil, such as fence posts, poles and general
foundation structures, should be commercially pressure treated.
PRE-CONSTRUCTION TREATMENT OF
Control subterranean termites by preventing the termite colony in the
soil from entering the structure. It is impossible to build structures
so termites cannot cause damage. Therefore, a thorough
pre-construction treatment should be applied to protect the structure
for 5-20 years. Houses treated prior to 1988 with chlorinated
hydrocarbons, should be protected from subterranean termites for 30-40
years. Several insecticides have proven satisfactory for making
effective barriers when properly applied.
PRE-CONSTRUCTION TREATMENT OF
FOUNDATION WALLS AND PIERSF A Q's-BACK TO THE TOP
After the footings are poured and the foundation walls and/or piers
have been constructed, apply the insecticide to a trench in the soil
about 6-12 inches wide and 4-6 inches deep adjacent to the foundation.
The insecticide must be applied to both the inside and outside of the
foundation and also around piers, chimney bases, pipes, conduits and
any other structures in contact with the soil. The trench should be as
deep as the top of the footing. The insecticide should be mixed with
water as recommended on the pesticide label and applied at the rate of
2 gallons per 5 linear feet of trench. The insecticide should be mixed
with the soil as it is being replaced.
PRE-CONSTRUCTION TREATMENT OF CONCRETE
SLABS The most common type of construction in Florida is concrete slab
resting on the soil. Often the slabs crack or shrink away from the
foundation wall allowing termites to infest the wood above. The soil
underneath and around the concrete slab should be treated with
insecticide before the concrete slab is poured. The chemical should be
applied after all the subslab fill and reinforcement rods are in
place. Apply diluted spray to the fill at the rate of 1 gal. per 10
sq. ft. Along both sides of foundation walls and interior foundation
walls and plumbing (critical areas), apply diluted insecticide at the
rate of 2 gal. per 5 linear feet. Treat all hollow masonry units of
foundations with I gal. of diluted spray per 5 linear feet. Apply the
insecticide to reach the footing.
POST-CONSTRUCTION TREATMENT OF
Crawl Space Treatment Dig narrow trenches along both the inside and
outside of foundation walls and around piers and chimney bases, and
apply diluted spray as described above. Also be sure to trench and
treat around sewer pipes, conduits and all other structural members in
contact with the soil. Apply the insecticide to the trenches. The
insecticide must be applied to both the inside and outside of the
foundation and also around piers, chimney bases, pipes, conduits and
any other structures in contact with the soil. The trench should be as
deep as the top of the footing. Mix the insecticide with water as
recommended on the pesticide label. Apply the diluted spray at the
rate of 2 gal. per 5 linear feet of trench. Mix the insecticide with
the soil as it is being replaced.
Concrete Slab Construction
It is possible to trench around the outside of a slab after it has
been poured, as described above, but this alone usually will not give
satisfactory control because the termite colony may be entering the
structure from the soil under the slab. Homeowners are not equipped to
treat under slabs after the slab foundation is completed. A
professional pest control operator usually is needed to do subslab
chemical injections. Most subterranean termites feed along the grain
of the wood, eating the spring wood and leaving the summer wood. The
Formosan termite feeds on both and forms a hollow. In Hawaii, where
unprotected homes were built over large colonies, records show that
the Formosan subterranean termite caused major structural damage in 6
months and almost complete destruction in 2 years (Tamashiro 1984).
Moisture Requirements The Formosan termite, like all subterranean
termites, uses the soil for a source of moisture. However, Formosan
termite colonies can obtain moisture from plumbing or roofing leaks.
INSPECTION OF CONCRETE SLAB
Inspect for evidence of termite activity near any plumbing that goes
through the slab. Look for tubes around baseboards. Tap baseboards
around walls. Check for wood which is in contact with the soil.
THE VACANT HOUSE
- "Greenhouse Effect"
CAUSE: Security -conscious vacationers,
a homebuilder's unsold inventory, whenever a wood floor is deprived of
an air flow in the environment, it can and will misbehave. Sunlight
through windows generates heat, lowers humidity, moisture vapor enters
to balance, nights cool off, humidity builds and wood floors cup.
Thermostats set at 60 degrees and outside, winter howls, heating
system runs constantly with no moisture added, and floors shrink.
CURE: Avoid problems by leaving
windows "ajar", have neighbor air the house out
occasionally. Treat floors as discussed under cupped, tented, or
shrinkage cracks and only after environment returns to normal. Owner
The above commonly ask questions will help you and your wood floor
contractor resolve some of the everyday concerns about wood floors. By
no means is this a sure method or procedure. If in doubt, get a second