tile may be installed over ordinary drywall, which
IN THe BaSemeNT
deteriorates if it absorbs water. One remedy is
tearing out the tile and drywall and installing a
Safety note: Stay out of basements or crawlspaces
cement-based backer board before retiling.
if there’s standing water, wet soil, or substandard
Check tub–wall joints closely. They must be well
electrical wiring! Metal pipes or ductwork could
caulked to forestall leaks.
become energized by a short circuit.
Use your pocketknife awl to prod gently for
Dampness can be mitigated by regularly
damage under lavatory and kitchen sink cabi-
cleaning gutters and downspouts, as well as grad-
nets. Rusted-out drainpipes or leaking supply-
ing the soil around the foundation so it slopes
pipe connections are easily replaced, but exten-
The water damage and rot beneath
away from the house. Musty smells and occa-
sive water damage to the subfloor or floor joists
this toilet could have been avoided by
sional condensation may be reduced by improv-
replacing a $2 wax gasket.
can be a major repair.
ing ventilation. Beyond that, fixes get more com-
plex and more expensive.
16
Chapter 1
Wetness is often caused by surface water and
Given the magnitude of the problem, the engi-
may respond to the previous suggestions. Stronger neered solution may be very expensive.
remedies include sump pumps, perimeter drains,
Older foundations of unreinforced concrete
and engineered solutions. For example, water
or brick may be adequate beneath single-story
seeping through an uphill foundation wall may
houses on flat lots, but long term, you should
need to be intercepted and rerouted by drain-
plan to replace them. Unreinforced foundations
pipes or swale drains farther uphill. Such solu-
are often poor quality (crumbling) and may have
tions can be expensive.
cracks that go all the way through the concrete.
Cracks range from cosmetic surface lines that Wood structures are most often damaged by
you can ignore to larger, deeper fissures caused
sustained moisture below grade, insects, settling
by water pressure, soil movement, foundation
of the foundation, or unwise sawcuts into sup-
failure, or a combination of those causes.
porting members during earlier remodels.
In general, a serious crack is any gap that runs
If you see signs of water damage or rotted sid-
through the foundation or is at least 1⁄4 in. wide,
ing, use your pocketknife awl to probe the perim-
combined with foundation rotation. (In brief,
eter of the mudsill—and the studs atop it—for rot
rotation is caused by horizontal soil pressures
or insect damage. To prevent recurrence of rot,
that push a foundation wall out of plumb.) Have
you’ll need to replace damaged sections with
a structural engineer assess the cause and recom-
mend a solution.
Vertical cracks through a foundation that are
wider at the top may be caused by differential
Knob-and-Tube
settlement. For example, a corner of the house
Wiring
may be sinking because of drainage problems or
a second-story addition that’s too heavy for the
If you see individual wiring secured to ceramic
original foundation.
insulators in the basement or attic, that’s knob-
Horizontal cracks through the foundation
and-tube wiring. Although outdated, it’s gener-
wall, just below ground level, may be caused by
ally acceptable if it’s in good condition and used
adfreezing, in which damp soil freezes to the top
only for lighting. To be safe, check with your local
of a foundation and lifts it. This condition most
code officials or a licensed electrician—and then
often occurs in unheated buildings.
with your prospective insurance company.
The foundation’s bowing-in along horizontal
cracks is extremely serious; it’s caused by soil
movement and strong hydrostatic pressure.
Knob-and-tube wiring is outdated but often serviceable.
Reading a House
17
eLeCtriCaL Safety near Water
Kitchen receptacles within 4 ft. of a sink
and all bathroom receptacles must be
protected by GFCIs. They’re essential
protection against electrical shock.
Note, however, that local codes have the
final say on what’s acceptable in your
community.
treated lumber, improve drainage, slope soil
away from the house, and so on.
If you encounter sagging girders or joists, the
posts and pads supporting them may have failed.
In this case, upsize the concrete pads beneath the Use a voltage tester to check receptacles. The inductance
posts and/or replace the posts. In some cases, you tester shown often can detect electrical current nearby—
such as through a plastic cover or a lamp socket—without
can shorten joist spans by adding girders and
actually touching a conductor.
posts beneath.
Wooden posts rotting at the bottoms suggest
that moisture is wicking up from the ground
In older homes, electrical service is often under-
through the concrete pad—if there is one.
size. If your house has only two cables running
Replace the posts, putting a metal or plastic
from the utility pole, it has only 120-volt service.
moisture barrier between the bottoms of posts
After purchasing the house, have your power
and the concrete pads supporting them.
company upgrade to three-wire, 240-volt service.
Joists and girders may have been seriously
A 100-amp, circuit-breaker service panel is
weakened when they were cut improperly to
considered minimal today. If an older home has a
accommodate ducts or pipes. See “Maximum
fuse panel, it will typically have a capacity of only
Sizes for Holes and Notches” on p. 341 for tips
60 amps. It should be upgraded.
on how much and where you can safely cut and
Knob-and-tube wiring does not necessarily
drill structural members.
have to be replaced, but it does not include a
ground wire and it has its limitations.
Any electrical cable with cracked or frayed
Mechanical Systems
sheathing should be replaced. Deteriorated cable is
Mechanical systems include electrical, plumbing, usually visible as it approaches the service panel
and HVAC. Your comfort and safety depend on
and as it runs along joists in attics and unfinished
up-to-date and adequately sized mechanicals, as
basements. Visible wire splices or cable that sags
they are sometimes called.
from joists is unsafe and substandard. Don’t han-
dle such wiring. Just note its condition.
eLeCTRI
CaL SYSTem
Using a voltage tester, you can safely check
Only a licensed electrician should assess the
whether receptacles are operable. If the cover
capacity and condition of your electrical service.
plates of any receptacles are warm, if tester lights
In particular, do not remove the covers of service
flicker, or if there’s an odd smell, there may be
panels. Before examining receptacles, switches,
aluminum circuit wiring in the walls, which tends
and other devices, always turn off the electricity
to overheat and cause fires if incorrectly installed.
and make sure it’s off by using a voltage tester
Have your electrician check for this, too.
before handling any electrical device.
To prevent electrical shocks in high-moisture
If you see scorch marks, rust stains, or con-
areas, all bathroom receptacles, kitchen recepta-
densation on the service panel or damp condi-
cles within 4 ft. of a sink, outdoor outlets, and
tions around it, that service is unsafe. Dampness
some garage outlets must be ground-fault circuit
is particularly unsafe, and many electricians will
interrupters (GFCIs). All new 15-amp and
refuse to work on a panel until surrounding
20-amp circuits in bedrooms must have arc-fault
dampness is remedied.
circuit interrupter (AFCI) protection.
18
Chapter 1
pLumBINg
Septic
Questions suggested under “Kitchen and
tips
Bathrooms” earlier in this chapter should be
If the house has a septic tank, ask when it was
addressed here, too—particularly if you noted
last emptied. Most tanks are sized according to
water damage around tubs or toilets. By the way,
if the house has only a crawlspace, replacing the
the number of users and should normally be
plumbing will take longer and be more costly
emptied every few years. Also inquire how the
than if the house has a full basement.
owner determines the exact location of the
tank’s clean-out lid, which will usually be buried
drainage, waste, and vent (dWV) pipes should
under more than 1 ft. of soil.
be replaced if they’re rusted, corroded, or leaking.
Then walk the area around the tank. If the
Waste pipes past their prime often show powdery
green or white deposits along their horizontal
ground is damp and smelly, the most recent ser-
runs, where wastes accumulate. Also, if joists
vicing wasn’t soon enough. Besides tardy servic-
around a closet bend (see p. 336) are discolored,
ing, this could indicate that the tank or the
probe for rot. If rotted, they’ll need to be replaced.
drainage field may be undersize, clogged, or
incorrectly installed. A new septic system is a
supply pipes. If water pressure is poor and
plumbing is old, it’s likely that the pipes are gal-
significant expense.
vanized iron. With a typical life span of about
25 years, the fittings rust out first.
Copper pipe will last indefinitely unless the
water is acidic, in which case you’ll see blue-
green deposits on fixtures and pinhole leaks in
P R O T I P
the pipe. But if copper pipes aren’t too far gone,
an acid-neutralizing filter on supply lines may
If cleanout traps show fresh
cure the problem.
wrench marks, suspect recent
Copper and galvanized pipe joined together
clogging; if traps are badly
will corrode because of a process called galvanic
scarred, they have been opened
action. To join these metals, a dielectric union
many times. This may mean
should be installed between them.
nothing more than children drop-
ping things down the sink or it
A water test by the health department should
may indicate an inadequately
be part of the purchase agreement; this is espe-
sized pipe that needs replacing
cially important if the house has its own well.
(see “minimum drain, Trap, and
Water heaters. Water heaters more than 12 years
Vent Sizes” on p. 335).
old probably should be replaced. A manufactur-
If a cast-iron waste pipe is this rusty, it needs replacing.
er’s plate on the heater will tell its age and capa-
city. As a rule of thumb, a 40-gal. gas-fired water
heater is about right for a family of four. Electric
water heaters should have a capacity of 50 gal.
because they take longer to recover.
pipe Life and
Water quaLity
If supply pipes are galvanized steel, their useful
life is about 25 years. Copper supply pipes
installed before 1990 may contain lead in solder
joints, which can leach into drinking water. So
before making an offer on a house, get the water
tested for lead and other toxins. If the pipes
appear to be otherwise in good condition, an in-
line filtration system with replaceable filters may
be a cost-effective solution to this problem.
Corroded galvanized-steel pipe atop a water heater tells you it’s time to replace both the heater
and the supply pipes.
Reading a House
19
Tankless water heaters create hot water on
If the bottom of the heating unit is rusted
P R O T I P
demand, so they lack a tank; p. 353 has tips on
out or if it’s 15 to 20 years old, it probably
selecting them. Any gas-fueled water heater—
should be replaced. It’s certainly not efficient
If your old hot water heater
whether tank or tankless—must have an
and probably not safe.
needs replacing, installing a tank-
approved vent to exhaust combustion gases.
less water heater may lower your
Soot around heat registers or exhaust
Electric water heaters do not require a vent.
energy bills. Tankless models cre-
smells in living areas means that the furnace is
ate hot water on demand, so
There should be a temperature- and pressure-
dirty and poorly maintained or that the
there’s no energy wasted keeping
relief (TPR) valve on or near the top of the water
furnace heat exchanger is cracked, allowing
a tank of hot water hot until some
heater. Without TPR protection, a water heater
exhaust gases to escape. If an HVAC specialist
one needs it. and, especially in
can explode and level the house. If the TPR valve
can see flame through the heat exchanger, it’s
mild climates, tankless water
drips, replace it. If you own the home, make sure definitely time to replace the unit. It may be a
heaters can be installed on the
you have a TPR valve.
fire safety and health hazard.
exterior of the house, freeing up
Gas lines that smell and corroded gas pi
pes
If your house has forced hot-air heat, your
precious space inside.
are unsafe. If you spot either of these problems,
family could develop respiratory problems if the
call the gas utility immediately (most provide a
furnace has one of the older, reservoir-type
free inspection). Gas lines are typically black iron humidifiers, which are notorious for breeding
pipe with threaded fittings or copper joined by
harmful organisms in the always-wet drum.
flared fittings. Gas lines should never include
An HVAC specialist can suggest alternatives.
PVC plastic pipe, sweated (soldered) copper
If certain rooms are always cold, an
joints, or compression fittings such as those used HVAC specialist may be able to balance heat
for water supply.
distribution or add registers. That failing, you
may need to upsize the furnace or boiler.
HeaTINg, VeNTILaTIoN,
If ducts, pipes, or the central heating unit
aNd aIR-CoNdITIoNINg
are wrapped with white or gray paper-tape,
Heating and cooling systems are varied and com-
your older heating system may be insulated
plex, so make your house purchase contingent on with asbestos. Do not disturb it—an HVAC
a professional inspection by an HVAC contractor. specialist can assess its condition and
In your walk-through, look for the following:
recommend an asbestos-abatement expert.
Air-conditioning (AC) systems that run
constantly but don’t keep the house cool may
need the coolant to be recharged. An AC
system that cycles too rapidly and makes the
house too cold may simply be too large for the
house. Both problems just need adjustments
by an HVAC contractor.
FIRepLaCe oR WoodSToVe
Loose bricks in the fireplace firebox or smoke
stains between the wall and the fireplace mantel
(or surround) could allow flames or superheated
gases to ignite wood framing around the fire-
place. A mason or chimney specialist can usually
make necessary repairs.
If there are gaps between the hearth (firebox
floor) and the hearth extension, stray coals could
fall into the gaps and start a fire, so repoint gaps
with mortar (if there’s brick) or grout (tile floors).
Local building codes usually specify mini-
mum distances woodstoves and stovepipes must
be from flammable surfaces.
A TPR valve can prevent water-heater explosions caused
Renovation 4th Edition Page 5
