When you install wood flooring, it is essential that you are aware of the moisture content of the subfloor on which you will lay your new floor as well as the moisture content of the wood flooring you are about to lay. Moisture testing can be as detailed or as approximate as your job warrants but it is something you choose to ignore at your peril. That said, all moisture testing of wood flooring comes with an appropriate “Health Warning” which states that the moisture levels tested can only ever be a snapshot of what the conditions are at any one time and are no guarantee of what may or may not happen in the future.
If you plan to have your floor professionally installed, your floor fitter should have made allowances in his project plan for the accurate moisture testing of both your subfloor and your new flooring product. What’s more, he or she should have the skills and the tools to do the job effectively and evidence to you that the job has been done correctly.
If you are planning wood flooring moisture testing on a DIY basis, this is a completely different proposition and should be approached with preparation and a degree of caution. As well as the use of moisture meters, there are three commonly used moisture testing methods for concrete. They are:
- The Calcium Chloride Test
- The Polyfilm Test
- The Phenolphthalein Test
The Calcium Chloride Test
The Calcium Chloride Test is one of the oldest and most commonly used moisture tests for concrete sub floors. This test involves the sealing of a small plastic dish of anhydrous calcium crystals over a sanded or scratched concrete surface for anything between 60 and 72 hours. The moisture content of the concrete is determined by the difference in weight between the crystals at the start of the test and at the end. The test results will be expressed in grams per square meter by the testing centre.
The Polyfilm Test
The Polyfilm Test is somewhat less scientific, but equally effective, some argue. This test involves the taping of several large pieces of plastic film in key locations over the concrete floor. If there are signs of moisture on or around the polyfilm after 24 hours eg. condensation or darkening of the concrete, then further testing or drying out is required.
The Phenolphthalein Test
The Phenolphthalein Test involves drilling holes in the concrete and inserting drops of the test solution into the holes. Colour changes in the solution indicate moisture.
Side by side
| Test Method | Description | Level of Complexity |
|---|---|---|
| The Calcium Chloride Test | This is one of the oldest and most commonly used moisture tests for concrete subfloors. It involves sealing a small plastic dish of anhydrous calcium crystals over a sanded or scratched concrete surface for 60 to 72 hours. The moisture content is determined by the difference in weight between the crystals at the start of the test and at the end. Results are expressed in grams per square meter by the testing centre. | Medium: Requires special materials and understanding of weight measurement. |
| The Polyfilm Test | This method is somewhat less scientific but argued to be equally effective. It involves taping several large pieces of plastic film in key locations over the concrete floor. If there are signs of moisture on or around the polyfilm after 24 hours (e.g., condensation or darkening of the concrete), then further testing or drying out is required. | Easy: Requires just a plastic film and observational skills. |
| The Phenolphthalein Test | This test involves drilling holes in the concrete and inserting drops of the test solution into the holes. Colour changes in the solution indicate moisture. | Complex: Involves drilling into concrete and interpreting chemical change |
When it comes to the moisture testing of the wood flooring itself, most professional flooring suppliers suggest that new flooring should be left to acclimatise in its new environment prior to fitting.
—
FAQ
1. Why is moisture testing important in the installation of wood flooring?
Moisture testing is crucial in the installation of wood flooring as it ensures you’re aware of the moisture content of both the subfloor and the wood flooring you’re about to lay. Ignoring moisture testing can lead to issues with the flooring in the future. However, it’s important to note that the moisture levels tested are only a snapshot of the conditions at that particular time and do not guarantee future conditions.
2. Who should carry out the moisture testing during wood flooring installation?
If you plan to have your floor professionally installed, your floor fitter should conduct the moisture testing. They should have allowances in their project plan for accurate moisture testing and possess the skills and tools to do the job effectively.
3. Can I perform moisture testing on a DIY basis?
Yes, moisture testing can be done on a DIY basis, but it should be approached with preparation and caution. There are three commonly used moisture testing methods for concrete subfloors: The Calcium Chloride Test, The Polyfilm Test, and The Phenolphthalein Test.
4. What are the different moisture testing methods for concrete subfloors?
The Calcium Chloride Test involves sealing a small plastic dish of anhydrous calcium crystals over a sanded concrete surface for 60 to 72 hours. The Polyfilm Test involves taping large pieces of plastic film over the concrete floor and checking for signs of moisture after 24 hours. The Phenolphthalein Test involves drilling holes in the concrete and inserting drops of the test solution into the holes, where color changes in the solution indicate moisture.
5. How should I prepare the wood flooring for moisture testing?
Most professional flooring suppliers suggest that new flooring should be left to acclimatise in its new environment before fitting to properly prepare it for moisture testing.