E. coli
Direct fecal indicatorA gut bacterium. Finding it in the fill means sewage reached it, not just clean water.
Bacteria & Sewage Screening
sewage bacteria testing under floors.
Post-Sewage & Sub-Floor Bacterial Clearance · ISO 17025 accredited lab
When sewage, grey water or flood water gets under the tiles, it soaks into the sand or shumshum fill beneath them and stays there long after the floor looks dry. We take sterile samples of that fill, ship them refrigerated to a partner microbiology laboratory accredited to ISO/IEC 17025, and you get a clear answer: conforming, or active contamination that means the fill has to be sanitised or replaced.
- 3Fecal indicators
- 17025Lab accreditation
- 10Days to the report
ISO 17025 lab test
every sample is tested by a microbiology laboratory accredited to ISO/IEC 17025.
The accreditation belongs to our partner laboratory, and it is what turns a result into evidence: a validated method, calibrated equipment and a signed laboratory report. The lab tests for three fecal indicator bacteria and reports them in CFU per gram.
Coliform bacteria
Total coliformsA broad group used as a general measure of sanitary quality. A high coliform count in the fill under a house floor says it has not returned to a clean state.
Enterococcus
Long-lasting indicatorTends to survive in wet sand and fill longer than E. coli, so it can still point to sewage after E. coli has faded.
When to call
sewage contamination under tiles, and what it leaves behind.
The test fits any case where contaminated water reached under the floor, or where you need to prove it is no longer there.
A sewer stack or line backup
A blockage in the shared line that flooded the flat through the drains, the toilet or the shower.
A grey or black water leak
A cracked drain pipe, a leaking toilet connection or a waste line that leaked into the fill over time.
A flood
Water that stood on the floor and soaked through the grout and joints into the sand or shumshum.
A sewage or musty smell under tiles or parquet
A smell that comes back after cleaning and drying, usually along the walls and in the wet rooms.
Sanitary clearance before moving back in
Before you move back, before you let the flat again, or before new flooring goes down over the fill.
Evidence for the insurer
When the insurer, a neighbour or the building committee disputes the extent of the damage, an independent lab result settles it.
Wet sand and shumshum
the tiles are dry. the fill under them may not be.
Most floors in Israel sit on a layer of sand or shumshum. It soaks up water like a sponge and holds it for weeks or months, out of reach of any dehumidifier. What to do with it is the most expensive decision of the whole restoration.
Tearing up the whole floor for nothing
Without a test, the only safe option is to replace all the fill in every affected room. Testing area by area shows where the fill is actually contaminated, and where the floor can stay.
Re-tiling over active contamination
Contaminated fill sealed under new tiles keeps smelling. When the smell comes back, the new floor comes up again, this time at your expense.
Arguing without numbers
The insurer, the contractor and the neighbour can all say the fill is fine. A bacteria count in CFU per gram on an accredited lab certificate is a number nobody argues with.
Required before the visit
an opening to the fill must be ready before we arrive.
The sample is taken from the sand or shumshum itself, so every area tested needs at least one opening. You or your contractor prepare it before the visit, in one of three ways:
Under parquet it is the same: one board lifted or a section of skirting removed. Without an opening ready, no sample can be taken and the visit has to be rebooked. Tell us on the call how many areas were affected and we will tell you how many openings to prepare, and where.
How it runs
from the call to the sanitary clearance.
The sampling visit is short. Most of the time is laboratory work, and the chain of custody keeps the result standing when someone else challenges it.
- CallWhat happened, and whereThe kind of water, when it happened, which rooms were affected. We agree the sampling points and the openings to prepare.
- SampleSterile samplingSterile tools for every point, sealed and numbered containers, and a photo and location for every sample.
- Cold chainRefrigerated to the labSamples travel refrigerated, with a chain of custody form, to our partner microbiology laboratory accredited to ISO/IEC 17025.
- ReportSanitary reportResults and the sanitary report within 10 business days of sampling, with the lab certificate attached.
Lab resultISO/IEC 17025
Sample 2 · shumshum under the bathroom floor
- E. coli1,200 CFU/g
- Coliforms15,000 CFU/g
- Enterococcus< 10 CFU/g
Non-conforming: active contaminationThe fill in this area needs sanitising or replacing.
ConformingThe fill in this area shows no active fecal contamination.
Non-conforming: active contaminationThe fill needs sanitising or replacing before the floor is closed.
Sanitary clearance after a flood
one conclusion per area, nothing in between.
Every sampling point gets its three bacteria results and one of two conclusions, so you know exactly which fill to treat and which to leave.
- Results by point: E. coli, coliforms and Enterococcus in CFU per gram for every sample, with location and photo.
- The lab certificate: The certificate of the ISO/IEC 17025 accredited laboratory, attached to the report as issued.
- Conclusion and recommendation: For every area: conforming, or sanitise or replace the fill, and how far it extends.
- Clearance after the works: Once the fill has been sanitised or replaced, a re-test at the same points gives written confirmation that you can re-tile and move back in.
- A document that holds up: The testing is independent, which is why insurers, lawyers and property managers rely on the report.
Options
on its own, or added to a mold inspection.
The price depends on the number of areas and samples. Tell us what happened and we send you a written quote before the visit.
- Sterile fill samples in every affected area
- E. coli, coliforms and Enterococcus at an accredited lab
- Sanitary report with a conclusion per area
- Re-sampling at the same points
- Compared with the first results
- Written clearance before re-tiling and moving back
- Fill samples taken during the inspection visit
- Moisture, mold and bacteria in one picture
- Lab results reported with the inspection findings
Before you book
What people ask about sewage bacteria testing.
What does a bacteria test under the floor measure?
It measures three fecal indicator bacteria, E. coli, coliforms and Enterococcus, in samples of the sand or shumshum under the tiles or parquet. Results come in CFU per gram from our partner microbiology laboratory, accredited to ISO/IEC 17025, and the report states for every area whether the fill is conforming or actively contaminated.
Why is drying the floor not enough after a sewage backup?
Drying removes water, not bacteria. Sand and shumshum hold moisture and organic matter long after the tiles are dry, and a moisture meter cannot tell clean water from sewage. Only a lab test says whether the fill is still contaminated, and whether the floor can be closed over it.
What do I need to prepare before the visit?
An opening to the fill in every area tested: one tile removed, a section of skirting taken off, or an existing inspection hatch. You or your contractor prepare it before we arrive. Without an opening ready no sample can be taken, and the visit has to be rebooked. On the call we tell you how many openings are needed, and where.
How soon do I get the results?
Results and the sanitary report arrive within 10 business days of sampling. The samples leave refrigerated for the lab straight after the visit, and the lab certificate is attached to the report.
Can the report be used with my insurer?
Yes. The testing is independent, and the report gives the location of every sample, the lab results in CFU per gram and the accredited laboratory's certificate. Clients use it with insurers, loss adjusters, contractors, neighbours and building committees to settle the extent of the damage and the scope of the works.
Can the test be added to a mold inspection?
Yes. If you are already booking a mold inspection after water damage, the fill samples can be taken in the same visit, so moisture, mold and bacteria come back as one picture. Everything included is set out on your written quote.
What happens if the result is non-conforming?
The report states which fill needs sanitising or replacing and how far it extends, so the contractor works from findings rather than guesses. After the works, a clearance re-test at the same points gives you written sanitary clearance before you re-tile and move back in.
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