Tramex RHIH – Insulated RH Hood (Hygrohood)
An insulated hood that seals to the floor surface and lets relative humidity equilibrate beneath it, for non-destructive surface RH testing of concrete and other floors and screeds. It is used by flooring installers and inspectors where drilling the slab is not an option.
Non-destructive, and that is the point
The surface hood method does not require drilling into the slab. On a finished floor, in a tenanted building, or where the slab is post-tensioned, that matters a great deal. AS 1884-2012, the Australian standard for resilient floor coverings, describes the surface hood method, and Tramex states the Hygrohood complies with British Standard codes of practice BS 8201, BS 8203 and BS 5325, which call for the insulated impermeable hood method.
It is a different test from in-situ ASTM F2170, which measures humidity at depth inside the slab. Neither replaces the other. Check which one your flooring specification calls for before you test, not after.
What else you need
The hood is a sealed enclosure – it takes a relative humidity probe and a meter or logger to read it. Tramex lists it for use with a Tramex external RH probe and a CMEX5, a Feedback DataLogger DL-RHTX or a TREMS-Xtra remote monitoring system. A Hygro-i2 probe is used for hood tests, connected through the interface cable that matches your meter – RHIE2B for the CMEX5, MEX5 and DL-RHTX, or RHIE2 for the CMEX2 and MRH3. The hood itself is not connector specific. You will also need butyl tape to seal it to the slab.
How the test runs
- Expose the floor surface, clear it of any foreign material and sweep away dust so the hood can seal properly.
- Seal the insulated hood to the surface with butyl tape.
- Insert the RH probe into the hood and connect your meter, logger or TREMS-Xtra system.
- Allow the air beneath the hood to reach equilibrium with the slab before reading.
Avoid locations in direct sunlight or near sources of heat.
Specifications
| Type |
Insulated surface RH hood |
| Size |
195 x 195 x 55 mm |
| Construction |
ABS body |
| Method |
Non-destructive – no drilling |
| Standards |
BS 8201, BS 8203, BS 5325 hood method (Tramex); surface hood method in AS 1884-2012 |
Documents
Frequently asked questions
Is a hood test accepted instead of an in-situ test?
It depends entirely on the specification. The surface hood method and ASTM F2170 in-situ probes at depth are different tests, and flooring manufacturers' warranties often name one specifically. Read the specification before choosing the method – a correct test to the wrong standard is still a failed compliance check.
How long does the hood need to sit?
Long enough for the air beneath the hood to reach equilibrium with the slab surface. Lifting it early gives a reading of the room, not the floor.
Why does it need to be insulated?
Because a temperature difference between the hood and the slab drives condensation and skews the humidity reading. Insulation keeps the air space at slab temperature so the RH measured is the slab's.
Can it be used on a post-tensioned slab?
Yes, and that is one of its main uses. Post-tensioned slabs cannot be drilled without risk to the tendons, which rules out in-situ testing and leaves the surface hood method.
Not sure which RH test method your specification requires? Contact The Moisture Meter Company before you test.
