Are you running the numbers on a Johnston rental and wondering how to avoid surprise costs after closing? You’re not alone. In Polk County, a few big-ticket items can make or break your cash flow if you don’t plan ahead. In this guide, you’ll learn what to inspect, what it might cost, and how to budget for radon, roofs, sump systems, and floodplain issues before you write an offer. Let’s dive in.
Why CapEx planning matters in Johnston
Central Iowa weather and soil conditions can speed up wear and tear on roofs and put pressure on basements. Many homes in and around Johnston also sit in areas with higher radon potential. On top of that, floodplain status can affect your lending and insurance. A clear plan for these items helps you price offers, structure contingencies, and protect your net operating income.
Radon: test, verify, and budget
Johnston sits in a region with high radon potential. That means any basement-level living space or rental unit should be tested during due diligence. The EPA’s action level is 4 pCi/L, and many landlords aim even lower to reduce risk and tenant concerns. You can review national guidance on testing and mitigation from the EPA radon program and statewide resources through the Iowa Department of Public Health radon program.
What to check
- Order a short-term radon test during your inspection window.
- Review seller disclosures for prior test results and any existing mitigation system.
- If a system exists, confirm the fan runs, the manometer shows suction, and the discharge is properly routed.
Contingency tips
- Include a radon test in your inspection contingency.
- Specify your acceptable action level and remedies if results are high.
Typical costs and timing
- Professional short-term test: about $100 to $250.
- Sub-slab mitigation: about $800 to $2,500 depending on the home and routing.
- Installations are usually quick. Confirm any local permit and the mitigator’s licensing.
Roofs: age, storm wear, and replacement planning
Iowa’s hail, wind, and freeze-thaw cycles can shorten a roof’s life. Older roofs and those with prior storm claims can also affect insurability and premiums. If the roof is at or near the end of its life, you should plan reserves or negotiate repairs.
What to check
- Ask for roof age and look for curling, missing shingles, granular loss, and attic stains.
- Get a qualified roofer’s inspection when possible.
- Review any insurance claim history for hail or wind.
Contingency tips
- Include a roof inspection and require repair of active leaks or structural issues.
Typical lifespans and costs
- Asphalt shingles often last about 15 to 30 years depending on product and exposure.
- Replacement for a typical single-family home commonly runs about $5,000 to $15,000, with premium materials higher.
Sump pumps and drainage: keep basements dry
Many Johnston homes rely on drain tile and sump pumps to manage groundwater. Clay soils and seasonal runoff can push water toward foundations, so you want to confirm the system works and plan for backups.
What to check
- Ask for sump pump age, type, and whether a battery backup is installed.
- Look for signs of water intrusion: efflorescence, staining, patched cracks, dehumidifiers, or fresh coatings.
- Check grading and downspout discharge away from the foundation.
- Consider a sewer scope if you suspect issues that could relate to backups.
Contingency tips
- Include a mechanical check of the sump and ask the seller to run it during inspection.
Typical costs
- Primary sump pump replacement: a few hundred dollars to about $1,000 installed.
- Battery backup system: several hundred dollars to about $1,500+ depending on features.
- Interior perimeter drains or professional waterproofing: commonly $3,000 to $10,000+.
Floodplain status: underwriting and insurance
Floodplain designation is evaluated early in underwriting and can impact both loan approval and annual operating costs. If a structure sits in a Special Flood Hazard Area, federally regulated lenders typically require flood insurance. You can look up a parcel’s preliminary status with the FEMA Flood Map Service Center and learn about policy pricing under FEMA’s modern risk-based approach on the FEMA NFIP site.
What to check
- Verify the property’s flood zone using FEMA maps or Polk County GIS.
- Ask your lender to order the formal flood determination early.
- If needed, obtain an Elevation Certificate to refine insurance pricing.
- Review any local floodplain permits, restrictions, or mitigation steps.
- Ask the seller about any prior flood events or insurance claims.
Contingency tips
- If the parcel is in an SFHA, add time to secure quotes and review elevation data.
Typical insurance costs
- Premiums vary widely. They can be under $1,000 per year in some zones or several thousand dollars per year for structures lower in the SFHA, especially with basements or prior losses. Get a quote on the specific parcel before you finalize an offer if flood risk is possible.
Other recurring CapEx to monitor
- HVAC age and replacement cycles, typically about 15 to 20 years.
- Water heater age and plumbing type in older homes.
- Windows and siding for efficiency and condition.
- Driveway and garage door wear from freeze-thaw and salt.
- Any municipal assessments, stormwater fees, or planned local improvements.
A simple due-diligence timeline
Pre-offer quick checks
- Review FEMA flood maps for the parcel.
- Check Polk County and City of Johnston records for year built, permits, and any noted roof or mitigation work.
- Read the seller disclosure for roof age, radon tests, sump details, and past water issues.
- If the roof is 15 to 20 years old or more, plan for near-term replacement.
During your inspection window
- General home inspection with roof-access and attic review.
- Radon test included in your contingency.
- Roof inspection by a qualified roofer with a written estimate if needed.
- Operate the sump pump and inspect for water intrusion evidence.
- If near or in an SFHA, order an Elevation Certificate and get flood quotes.
- Add a sewer scope where appropriate.
Lender and insurance conversations
Tell your lender early if flood risk is possible and get the flood determination ordered.
If the seller claims mitigation or backups are installed, request documentation, receipts, and any warranties.
Budget shortlist before you write offers
Use these placeholders to stress-test cash flow. Always get local bids.
- Radon test: $125 to $250.
- Radon mitigation (if needed): $800 to $2,500.
- Roof replacement reserve: plan $5,000 to $15,000 depending on size and material.
- Sump pump replacement: $300 to $1,000.
- Battery backup for sump: $300 to $1,500.
- Interior basement waterproofing: $3,000 to $10,000+.
- Flood insurance (if in SFHA): obtain a parcel-specific quote.
- Immediate repairs reserve (plumbing/HVAC): $1,000 to $5,000 depending on age and findings.
Local rules and helpful resources
- City of Johnston: Check building permits, floodplain rules, and stormwater guidance on the official municipal site.
- Polk County GIS and Planning: Review parcel-level data and floodplain layers via Polk County resources.
- FEMA Flood Map Service Center: Verify flood zones and Elevation Certificate info at the FEMA map portal.
- FEMA NFIP: Learn how modern, risk-based pricing works on the FEMA NFIP page.
- Iowa Department of Public Health Radon Program: State guidance and mitigator information via the IDPH radon program.
- EPA Radon: National testing and mitigation guidance at the EPA radon site.
Ready to build a smart CapEx plan for your Johnston rental? We can help you line up inspections, read disclosures, and budget with confidence before you write. Reach out to Unknown Company to start a focused rental acquisition plan today.
FAQs
What is the most common CapEx surprise for Johnston rentals?
- Radon mitigation and roof wear often top the list due to Iowa’s high radon potential and storm exposure. Test for radon and verify roof age before you offer.
How do I know if a Johnston property needs flood insurance?
- Check the parcel on the FEMA Flood Map Service Center and have your lender run a flood determination. If the structure is in an SFHA, insurance is typically required.
What should I ask a seller about the sump pump system?
- Ask for the pump’s age, model, and whether there is a battery backup. Request proof of maintenance and, during inspection, have the seller demonstrate operation.
How much should I reserve for a near-end-of-life roof?
- For a typical single-family home in the area, plan roughly $5,000 to $15,000, then refine with a roofer’s estimate during your inspection window.
What radon level should I target before leasing a basement unit?
- The EPA action level is 4 pCi/L, and many landlords aim for levels under that threshold. Include a radon test in your contingency and budget for mitigation if needed.
