In this review I will be looking at the Protimeter on-site chemical analysis kit. This is a fairly cheap bit of kit that would be used in conjunction with other on site tools to investigate the presence of rising damp. I do not aim to go through the full methodology of diagnosing rising damp nor am I going to touch on the treatment, I am going to be strictly keeping to the salt analysis.
Rising damp is a fairly rare phenomenon but when ruling out rising damp, an on-site salts test could be valuable. This kit is intended only for the testing of wallpaper or plaster samples for the presence of certain chlorides or nitrates mainly from the soil. Sub-soil naturally contains nitrates, from decaying plant matter, and chlorides.
This test will detect the presence of chlorides and nitrates within the test sample. The presence of both of these could indicate that the water in the sample came from the soil but as I will discuss later this might not be quite as simple as it seems.
Why Test for Salts?
When investigating a case of potential rising damp you will need to confirm a few factors, one of which being the presence of salts in the damp apex of the moisture profile. The salts are more abundant at the peak as this is where the majority of evaporation takes place. Nitrates and chlorides can be found within soil, so if soil bound moisture has risen up a wall these salts should be found.
These salts are hygroscopic which mean they absorb moisture from the air. This means even if the salts were deposited from a historic case of rising damp the wall will draw in moisture from the air and become damp making it seem like the issue is live. The salts hygroscopic action can take place with relative humidities as low as 55%.
If contaminants are residing within a wall, they will readily conduct electricity so they can give false readings to an electrical resistance meter, so if it is an historic case where the wall was at one time contaminated but now is dry, it will show on the electrical resistance meter as wet.
The testing for salts is a crude exercise and should be used as one small part of a suite of tools when diagnosing defects. The presence of salts does not really tell you the full story as there are a number of reasons they may have got there, I will discuss this in a bit more detail later on in the review.
Protimeter Salts Analysis Kit BLD4901 comes with the following:
- Nitrate no1. tablets (x10)
- Nitrate no2. tablets (x10)
- Chloride tablets (x10)
- Plastic scoop (x1)
- 100cc measuring beaker (x1)
- 60cc measuring beaker (x1)
- Bottle of de-ionised water (x1)
- Instruction leaflet
- Carry case
The case I was supplied with was a bit small for the kit but I am glad to say that if you look online a larger carry case is the standard spec so this shouldn’t be a problem. The instruction leaflet lays out in simple terms exactly what you need to do to conduct the test.
There really is not much to say on this kit as it is not meant to be a kit that comes with all the bells and whistles, its a very simple package of items geared towards testing the presence of chlorides and nitrates.
Testing out the kit
It can be the case that small traces of nitrates can be found in the potable water supply so it would be good practice to first test the potable water obtain a baseline. If the subsequent test is higher than this should indicate that there are nitrates which are not only coming from the water supply.
I tested three samples in total. A potable water sample, a cutting of external sandstone and a chlorinated sample. My hope was that I could possibly get some nitrates out of the sandstone and a good colour difference between the potable water and the chlorinated water samples.
The test is very quick to carry out and the process is very simple, so you will know within 5 minutes whether your sample is contaminated with salts. The caps for the beakers are not completely water tight so when I was shaking the beaker to mix the sample I noticed a little bit of water escaping but nothing major.
Just so that you can interpret the below results, the colours mean the following:
- Nitrate (60cc beaker test)
- Yellow – Negative
- Brown – Traces found
- Red – Positive in significant quantities
- Chloride (10cc beaker test)
- Brown – Negative
- Yellow – Positive
Analysing the results
As with many methods of testing, caution must be taken with the results. If the salt analysis test is negative this can be useful as this means that the moisture could be consistent with condensation or rainwater. If however, we find that salts are present, we must then proceed with caution. This is because chlorides, and sometimes nitrates, could be found if the following are present:
- Tap water (low Chloride, with a low/trace of Nitrate)
- Mortar additives containing chloride
- Detergents, like washing up liquid (I have been guilty of adding this to a mortar mix in the past)
- Chimney flue (soot contains hygroscopic salts)
- Salt water exposure – areas with lots of de-icing salts
- Contaminated agricultural buildings
My samples were all negative for nitrates, my chlorinated sample was obviously positive with chloride and the sandstone sample had a very slight colour difference in chloride to the potable water.
The major thing that is missing for me in the Protimeter kit is a colour chart to give an indication of the amount of nitrates or chlorides based on the change in colour. This means that the kit doesn’t provide a quantifiable result which would have been useful for this kind of test. This is going to make the process of comparing samples slightly harder.
The kit is geared up for a YES, NO or TRACE for nitrates and a YES/NO for chloride. If the kit came with a colour chart this would allow surveyors to make a more accurate assessment of the quantity of salts in a sample.
This being said, this cheap kit does what it sets out to achieve which is to confirm the presence of salts. Even though this kit will not be the most frequently used bit of kit in a surveyors arsenal, I think it is worth while to have for those occasions where salts are suspected.