Older homes make good rentals. They're often in established neighborhoods with mature trees and walkable streets. They sell below replacement cost. They have character that newer construction can't replicate. And they can generate strong cash flow relative to their acquisition price.
They also come with a set of maintenance realities that are entirely predictable — if you know what to look for.
After managing single-family rentals across Des Moines, Ankeny, Urbandale, and Johnston, certain problems come up again and again in homes built before 1990. Not because older homes are poorly built — many of them are better built than modern construction in certain respects. But because materials have lifespans, systems have service windows, and the particular climate and soil conditions of central Iowa create specific stress patterns that show up in specific ways.
This post documents the seven most common maintenance problems we encounter in older Des Moines area homes, what the warning signs look like, what it typically costs, and what landlords and investors should know before — or after — they buy.
1. Foundation Settling and Soil Movement
Des Moines sits on glacial till — dense, clay-heavy deposits left by glaciers thousands of years ago. That clay soil is the foundation of nearly every maintenance conversation about older homes in this metro.
Clay soil expands when wet and contracts when dry. It does this every year, every freeze-thaw cycle, every drought. In a home with a foundation built 60 or 80 years ago, that means decades of seasonal movement pressing against basement walls, shifting footings, and slowly opening cracks that were invisible at purchase.
What you actually see: The warning signs aren't always dramatic. Doors and windows that stick or no longer close squarely are one of the most reliable early indicators — in an older Des Moines home, that's usually structural movement, not just humidity swelling the wood. Diagonal cracks running from the corners of window and door frames in a stair-step pattern through brick or drywall. Gaps opening between walls and ceilings. Floors that have developed a noticeable slope. Horizontal cracks in basement walls — the most serious type, indicating lateral soil pressure pushing inward.
What it costs: Minor crack repairs run $500–$2,000. Pier installation to stabilize a settling foundation — the most common structural intervention in central Iowa — typically runs $1,250–$2,500 per pier, with most homes needing 5–10 piers. Total structural stabilization projects in Des Moines commonly run $5,000–$15,000. Deferred until walls bow significantly or footings shift materially: much more.
What landlords need to know: Older neighborhoods in Beaverdale, Sherman Hill, Drake, and Highland Park have higher-than-average rates of foundation issues due to housing age and the specific clay composition in those areas. A sewer scope and foundation inspection before purchasing any pre-1970 home in these neighborhoods isn't optional — it's the minimum due diligence. Catching a settling foundation at $3,000 is a manageable cost. Discovering it after it's compromised structural integrity is a different conversation entirely.
Normal settling that has been stable for decades is not necessarily a problem. Active, ongoing movement is. A structural engineer — not just a general inspector — can tell you the difference.
2. Plumbing: Galvanized Pipes and the Brown Water Problem
Homes built before roughly 1970 in the Des Moines area were plumbed primarily with galvanized steel supply lines — zinc-coated steel pipe that was the industry standard before copper and PEX became dominant. The zinc coating that prevents corrosion has a service life of about 40–50 years under normal conditions. In most of those homes, that service life has already passed.
What happens when galvanized pipe fails is not a burst — it's a slow, interior oxidation that builds up scale inside the pipe, progressively narrowing the flow path. The result is low water pressure that seems to get worse over time, water that runs slightly orange or brown after sitting in the pipe overnight, and clogs that recur no matter how many times you snake the drain. These symptoms don't fix themselves. They progress.
What you actually see: Discolored water when a tap is first opened — particularly after the home sits vacant between tenancies. Reduced pressure at multiple fixtures simultaneously, not just one (which would indicate a fixture-specific issue). Recurring slow drains in multiple areas of the home. Visible rust on exposed supply lines in the basement or under sinks.
What it costs: Partial galvanized replacement in an accessible section: $500–$1,500. Whole-house repipe from galvanized to PEX or copper: $4,000–$8,500 depending on home size, accessibility, and whether walls need to be opened. This is a significant cost — but it's also a one-time investment that eliminates a recurring maintenance category and typically improves insurance terms.
What landlords need to know: Galvanized plumbing is a tenant experience issue before it becomes a structural one. A tenant who opens the tap and gets brown water is not going to stay through lease renewal, and is going to tell other people about it. Properties with known galvanized plumbing should be disclosed to tenants and addressed in the capital planning budget. When evaluating a pre-1965 acquisition, factor the cost of a future repipe into your underwriting — it's not a matter of if, it's a matter of when.
3. Sewer Lines: Cast Iron, Clay, and Tree Roots
The sewer lateral — the underground pipe that carries waste from the house to the city main — is one of the most expensive surprises in older home ownership, and one of the most consistently missed at purchase.
Pre-1980 homes in Des Moines were served by either cast iron or clay tile sewer lines. Cast iron drain lines have a service life of 50–75 years under good conditions. Many of them are at or past that window. Clay tile sewer lines are often older, are inherently porous, and are a preferred destination for tree roots looking for water and nutrients.
Both materials fail in the same general ways: joints crack or separate over time, tree roots infiltrate the joints and build up until flow is blocked or the line collapses, and the inside of the pipe corrodes and deteriorates until it can no longer handle normal waste volume.
What you actually see: Slow drains across multiple fixtures — not just one, which typically indicates a localized clog. Gurgling sounds from drain lines. Sewage odors in the basement or around floor drains. In advanced cases, sewage backing up through the lowest floor drain. Patches of unusually lush grass directly above the buried sewer lateral, which indicates the line is already leaking and fertilizing the lawn.
What it costs: A CCTV sewer camera inspection — the only way to actually see the condition of the line — runs $150–$350 and should be non-negotiable on any pre-1980 purchase. Spot repairs where the pipe is accessible: $1,000–$3,000. Full lateral replacement using traditional excavation: $3,000–$8,000 depending on depth and length. Trenchless pipe lining or pipe bursting — which rehabilitates or replaces the line without major excavation — runs $6,000–$12,000 and is often the right call when the line runs under a finished basement floor, driveway, or significant landscaping.
What landlords need to know: A sewer backup during a tenancy is one of the worst maintenance scenarios in rental property management — it's a habitability emergency, it creates a potential health hazard, and the cleanup and repair costs can be substantial. Getting a camera inspection before purchasing eliminates most of that risk for a few hundred dollars. If you own a pre-1975 home with mature trees near the sewer lateral and haven't had a camera inspection in the last five years, add it to this year's maintenance list.
4. HVAC Systems: The Countdown You Can See on the Data Plate
Every furnace and central air conditioner has a data plate — a small label attached to the unit that shows the manufacturer, model, and serial number. Most manufacturers embed the installation year in the serial number, and most HVAC technicians can read it at a glance. That number tells you almost everything you need to know about near-term capital risk.
Furnaces have a service life of 15–25 years with proper maintenance. Central air units run 15–20 years. Iowa's climate stress — genuine winters with sustained periods below zero, genuine summers with heat and humidity — sits at the challenging end of the HVAC service life spectrum. A 22-year-old furnace in Des Moines has had 22 seasons of hard use.
What you actually see: The unit runs but struggles to maintain setpoint temperature on the coldest or hottest days. Unusual cycling — starting and stopping more frequently than normal. Increased gas or electric consumption for the same output. Visible rust or corrosion on the heat exchanger. A yellow or flickering burner flame rather than a steady blue one — which can indicate a cracked heat exchanger, a carbon monoxide risk, and immediate grounds to stop using the unit.
What it costs: Annual furnace and AC tune-up: $100–$200 per system and worth every dollar in extended life and early problem detection. Furnace replacement: $3,000–$7,000 installed depending on unit size and efficiency rating. Central air replacement: $3,500–$7,500 installed. Full HVAC system replacement: $8,000–$15,000+ depending on ductwork condition and home size.
What landlords need to know: Iowa's landlord-tenant law requires landlords to maintain functional heat — not as a convenience, but as a habitability requirement. A furnace that fails at 11pm on a January night in Des Moines is a landlord-emergency, a tenant-crisis, and a potential legal issue simultaneously. The practical answer is simple: know the age of the system before you close on a purchase, factor replacement into your capital budget if the unit is over 15 years old, and get annual tune-ups that include a heat exchanger inspection. An older furnace that's serviced annually and running well can give you several more years. One that hasn't been serviced in years is a liability.
5. Ice Dams: A Midwest-Specific Problem Most Investors Underestimate
If you're an out-of-state investor who grew up somewhere without serious winters, ice dams may be the single least intuitive item on this list. They're also one of the most expensive sources of water damage in older Iowa homes.
Here's the mechanism: in an older home with inadequate attic insulation, heat from the living space rises through the ceiling, warms the roof deck, and melts the snow accumulated there. That meltwater runs down the slope until it reaches the cold overhang — which sits above the exterior wall, beyond the insulation, and stays below freezing. The water refreezes at the eave, forming a dam of ice. More meltwater backs up behind the dam, has nowhere to go, and finds its way under the shingles, into the roof deck, and eventually through the ceiling.
By the time a landlord sees a water stain on a ceiling in February, the damage behind the drywall is often already significant.
What you actually see: Large icicles hanging from eaves after a snowfall — a warning sign, not a decorative feature. Ice formations along roof edges that grow after snow events. Water stains on interior ceilings or walls near exterior walls, appearing or worsening in winter. Damp or deteriorating insulation visible if you have attic access.
What it costs: Emergency ice dam removal: $300–$700 per event (and it needs to be done carefully — improper removal damages shingles). Water damage repair after ice dam infiltration: $2,000–$10,000+ depending on how long it's been going and how far it spread. The root-cause fix — properly air-sealing the attic floor and bringing insulation up to modern standards — costs $1,500–$4,000 for most Des Moines homes and permanently eliminates the problem.
What landlords need to know: Older homes in Des Moines often have attic insulation levels that were adequate by the standards of when they were built (R-11 to R-19) but fall well short of current recommendations (R-49 to R-60 for Iowa's climate zone). If you're buying a pre-1980 home and the attic inspection shows thin or compressed insulation, budget for an upgrade. That investment pays for itself in reduced ice dam risk, lower heating bills, and a more comfortable rental for tenants.
6. Knob-and-Tube Wiring: The Insurance Problem as Much as the Safety Problem
Knob-and-tube wiring was the standard electrical system in American homes built roughly from 1880 through the 1940s. It uses separate hot and neutral conductors routed through ceramic knobs (which hold the wire away from framing) and ceramic tubes (which protect the wire where it passes through joists and studs). It has no ground wire.
Properly installed and unmodified knob-and-tube in good condition isn't necessarily dangerous. The problem is that very little of it is unmodified. Over 80 years, previous owners added circuits, extended runs, buried the wire under attic insulation (which causes dangerous heat buildup), and added modern loads — refrigerators, washing machines, window AC units, televisions — far exceeding what the original system was designed to handle. The result is a system that may look intact but carries real fire risk.
What you actually see: In the basement or attic, you'll see the distinctive white ceramic knobs attached to framing members with single conductors stretched between them, and white ceramic tubes where the wire passes through wood. In the breaker panel, you may see a 60-amp service — the original capacity for knob-and-tube systems — rather than the modern standard of 100–200 amps. Outlets throughout the home will be two-prong (ungrounded) rather than three-prong.
What it costs: Replacing active knob-and-tube wiring with modern wiring: $5,000–$15,000 for most older Des Moines homes. For larger homes or those with significant access challenges (plaster walls, finished spaces), costs can reach $20,000–$25,000. Upgrading from 60-amp to 200-amp service: $1,300–$3,000 separately.
The insurance dimension is often the more immediate issue. Many Iowa insurers will not write a standard homeowners policy on a property with active knob-and-tube wiring. Those that will charge 50–100% higher premiums. Homes with knob-and-tube often end up in the surplus lines market — higher cost, narrower coverage, harder to maintain. If you're acquiring a pre-1945 property in Des Moines, find out the insurance situation before you close.
What landlords need to know: Knob-and-tube that has been deactivated and replaced throughout the home — which is often the case in homes that have been renovated — is not a concern. Active knob-and-tube that is still carrying load is a different matter. Your inspector should distinguish between the two, and you should verify the electrical report specifically addresses knob-and-tube rather than simply noting "older wiring present."
7. Basement Moisture: Central Iowa's Most Persistent Problem
If there's one issue that unites every category of older Des Moines home — pre-war bungalows, postwar ranch-styles, split-levels from the 1970s — it's moisture in the basement.
Central Iowa receives approximately 36 inches of precipitation annually, and spring snowmelt can raise the water table to within two to three feet of the surface in many Des Moines neighborhoods. The glacial till and clay soils that create foundation settling problems also drain poorly, which means water accumulates against basement walls for days after significant rain events. And the limestone and stone foundations common in the oldest Des Moines homes are far more porous than modern poured concrete.
What you actually see: Efflorescence — white, chalky mineral deposits left on basement walls after water evaporates through the masonry. This isn't structural damage, but it confirms water is moving through the wall. Visible moisture or water staining at the wall-floor joint, particularly after heavy rain. Rust on any metal objects stored on the basement floor. Mold or mildew — black, green, or white patches — on walls, wood framing, or stored materials. A persistent musty smell that doesn't go away when windows are opened. In more advanced cases, actual water on the floor after rain events.
What it costs: Improving grading and extending downspouts to redirect water away from the foundation: $500–$2,000 and the first thing to try. Interior drain tile system with sump pump installation: $3,500–$8,000 and provides permanent protection for most situations. Exterior waterproofing with membrane application (more disruptive, higher cost): $8,000–$15,000+. Mold remediation after moisture damage has allowed growth: $1,500–$10,000+ depending on extent.
What landlords need to know: Basement moisture falls squarely within Iowa's habitability requirements. Mold visible in a living space is not a maintenance annoyance — it's a potential habitability violation and a health concern for tenants. The practical approach is to address moisture at its source: grading, downspout extensions, and proper sump pump function are the first-line interventions that solve most problems. A sump pump with a battery backup — which keeps functioning through power outages that often coincide with the same storms causing water infiltration — is one of the highest-value mechanical investments in an older Des Moines basement.
Check the sump pump annually. Replace the backup battery every 3–5 years. Keep the discharge line clear. These are $50–$150 maintenance items that prevent the $5,000–$15,000 remediation.
What This Means for Landlords and Investors
None of these problems are disqualifying. The homes in Des Moines's established neighborhoods — Beaverdale, Drake, Sherman Hill, Urbandale, Ankeny's older sections — that have these issues are also the homes with the character, the location, and the price points that make them excellent long-term rental investments.
What separates investors who profit from these properties from investors who get hurt by them is simple: they knew what to look for before they bought, they budgeted honestly for what they found, and they maintain the systems they know are aging before those systems fail with a tenant inside.
The pattern across all seven problems above is consistent. Caught early, these are manageable capital expenses that fit into any realistic investment budget. Left until they fail — often during a tenancy, often in the middle of winter, often on a weekend — they become emergency costs, tenant relations problems, and occasionally legal issues.
At Caddie, our annual walk-through inspections are specifically designed to catch these patterns early. We know what aging galvanized plumbing looks like, what early foundation movement feels like underfoot, and what a sump pump that's struggling sounds like when it runs. Landlords who manage their own properties often don't have the repetition to build that pattern recognition. We do.
If you manage a Des Moines home built before 1985 and want a professional perspective on its maintenance profile and capital planning priorities, we're happy to take a look.
Cost estimates reflect general ranges for the Des Moines, Iowa metro area as of 2025–2026. Actual costs vary by property, contractor, scope of work, and access conditions. This post is for informational purposes only. Always consult licensed contractors and inspectors for assessments specific to your property.
