Read the guide: Can construction vibration damage my house?
How to monitor construction vibration at home
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Step 1: Start before the heavy work does. Log for an hour on a quiet evening or weekend, so you know what normal looks like in your home.
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Step 2: Use the lowest floor, on the side facing the work. Lay the phone flat, screen up, on the floor right next to the wall closest to the site. Concrete or tile is best.
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Step 3: Plug the phone in, turn off Low Power Mode or battery saver, and set auto-lock to Never for the day.
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Step 4: Tap "Start logging". On iPhone, tap Allow when Safari asks for Motion & Orientation access. Leave the phone alone and keep this page open in front.
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Step 5: Note what the crew is doing and when: pile driving, compacting, digging, breaking concrete, heavy trucks. Photos with timestamps work well.
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Step 6: At the end of the working day, stop the log and tap "Download PDF report" and "Download CSV". Keep one set of files per day.
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Step 7: Compare the peaks with the construction vibration limits for your type of home.
What your result means
Your result lands on one of four levels. This page uses the people and buildings scale, which is based on peak velocity in millimeters per second (mm/s).
| Level | Range (peak velocity) | What to do |
|---|---|---|
| Barely noticeable | Under 0.25 mm/s under 0.010 in/s | Background level. Most construction at a distance never gets above this. Nothing to act on. |
| Noticeable | 0.25 to 1.0 mm/s 0.010 to 0.039 in/s | You can feel it indoors if you're sitting still. Common when heavy equipment works nearby. Keep logging and keep your notes. |
| Strong | 1.0 to 2.5 mm/s 0.039 to 0.098 in/s | Clearly felt, and loose items may rattle. This is usually well below damage guidelines for ordinary homes, but it's fair to ask the contractor what they're doing and whether they monitor vibration. |
| Very strong | 2.5 mm/s or more 0.098 in/s or more | Strong for a home. If it happens often, send the site manager your report, photograph any cracks, and check the limits page. Old, fragile and historic buildings need extra care at this level. |
Professional construction vibration monitoring uses calibrated seismographs fixed to the ground or foundation and a report from an engineer. Your phone can’t replace that. What it can do is give you a dated record of when the shaking happened and how strong it was. That tells you whether you have a real problem, and it lets you talk to the contractor with facts instead of guesses.
Common causes and fixes
Caltrans notes that vibration from construction, like traffic, is mostly in the 10 to 30 Hz range. That’s mostly within a phone’s range, though close to its top. Each kind of work leaves its own pattern on the timeline.
Pile driving
An impact hammer shows up as a long run of repeated jolts, one per blow. A vibratory pile driver shows up as a long, steady event. If piles are going in close to your home, ask whether drilled or pressed-in piles are an option. They usually shake the ground much less.
Vibratory rollers and compactors
These make steady events that grow as the roller comes closer and fade as it moves away. Near homes, crews can often switch the roller to static mode (no vibration), use a lighter machine, or make more passes at lower power.
Demolition, breakers and digging
Hydraulic breakers and demolition make irregular bursts. Dropped loads make single jolts. Ask the crew not to drop heavy loads on your side of the site.
Trucks and steel road plates
Loaded trucks, and loose steel plates over trenches, make a sharp bang each time a truck passes. Loose plates are easy to fix, so report them to the contractor or the city.
What you can do
- Talk to the site manager first. Bring your report and ask what vibration limit the project uses.
- Ask for a pre-construction survey. Many contractors photograph nearby buildings before work starts.
- Photograph existing cracks now, with a ruler for scale and the date visible. Check them weekly.
- If you find new damage, tell the contractor in writing and contact your home insurer.
When you need professional construction vibration monitoring
Your phone log is for your own records and to start a conversation. For a dispute, hire a professional vibration monitoring company. Get one if your home is old, fragile or historic, already has cracks, sits very close to pile driving, blasting or vibratory compaction, or if your log often shows Strong or Very strong events. They place calibrated seismographs at your foundation, record the true peak velocity in three directions, and write a report insurers and contractors take seriously. On some projects the contractor pays for this, so ask first.
What this tool can’t measure
- The true peak of sharp jolts. The phone estimates peak velocity as RMS × √2. That’s exact for smooth, steady shaking but can read low for single hard impacts.
- Fast vibration. Phones measure up to about 30 Hz. The PDF report and the CSV list your phone’s exact limit. Some vibratory equipment runs close to or above that, and can then show up as a false lower frequency.
- The cause of a crack. Houses also crack from settling, drying lumber, and changes in temperature and moisture. A log shows when shaking happened, not what it did.
- Other spots. It only measures where it sits.
- Time while paused. Nothing is logged while the screen is locked or the page is in the background.
Phone readings are a good guide, not a certified measurement.
Frequently asked questions
How much construction vibration can damage a house?
It depends on the building and the type of work. For continuous sources like pile driving and vibratory rollers, Caltrans (2020) gives a guideline of 0.3 in/s (about 7.6 mm/s) peak velocity for older homes and 0.5 in/s (12.7 mm/s) for new ones. Fragile and historic buildings have lower values. See the construction vibration limits page for the full tables.
Will this report hold up in a dispute?
No. It's a good guide, not a certified measurement. Use it for your own records and to start a conversation with the contractor. For insurance claims or legal disputes, hire a professional vibration monitoring company that uses calibrated seismographs.
Where should I put the phone?
On the lowest floor, flat on the floor next to the wall that faces the work. Building guidelines usually refer to vibration at the foundation, and the lowest floor is the closest you can get. Keep it away from where people walk, since footsteps can swamp the reading.
Can I ask the contractor to monitor vibration?
Yes. Many projects already have a vibration monitoring plan with limits and seismographs near sensitive buildings, especially for pile driving, blasting or work next to old buildings. Ask the site manager, or your city's building or permit office, who is responsible and what limit applies.
Why doesn't my reading match the contractor's monitor?
Professional seismographs sample far faster than a phone and record the true peak on each of three axes. Your phone estimates peak velocity from the average (RMS × √2) and can't see vibration faster than about 30 Hz. The monitor is also in a different spot, often outside at the foundation.
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