We at H2O Remedial Services use the latest diagnostic instruments available in order to provide our Surveyors and Technicians with the correct information so as to establish if remedial treatments are necessary or not, the following instruments are used and calibrated on a regular basis to ensure optimum performance:-
Protimeter Survey Master: This combination enables our Surveyors to distinguish surface moisture from sub-surface moisture, essential information when trying to establish the extent and cause of a dampness problem.
Search mode (non-invasive)
By selecting search mode and holding the instrument against building materials such as walls, we can obtain a qualitative indication of the moisture level beneath the surface or under a floor covering.
By selecting Measure mode and pushing two needle electrodes into the surface of the wood or masonry under investigation, we can obtain, respectively, the actual moisture content or the materials wood moisture equivalent (WME) value. Additionally by utilising deep wall probes, further information can be gathered about moisture levels deep within a wall cavity or structure.
Hygrometer: This instrument is used to measure the relative humidity, dew point and ambient temperature.
A sensor supplied with the instrument can also be embedded in solid floors and walls to obtain a materials equilibrium relative humidity (ERH) value.
Surface temperature measurements can also be provided, making this instrument especially suitable for condensation risk assessment and diagnosis.
Data logging: This is one of our remote data loggers to record Relative Humidity Levels at timed intervals, the data logger is left when set in place, for the required period of time. The memory contents are then downloaded to a PC where the logged measurements are displayed in tabular and graphical form. Useful to resolve mould growth issues,if disputes arise between Housing Associations and their residents, for example.
As with all electrical Moisture Meters the results must be correctly interpreted.
Salt Analysis: One way of finding the source of moisture is by way of undertaking a simple on site salt analysis, we can thus establish if Nitrates are present in a plaster sample. Nitrates are derived from the decay of organic compounds thus present in the soil, therefore if these salts are detected, as the salts only move in solution, this would indicate moisture from the soil.
This test is quite simple, with colour changes indicating the presence or not of Nitrates and Chlorides.
Speedy Calcium Carbide Meter: This instrument whilst more accurate than an electrical conductivity meter and gives a quantitative reading, it is a destructive method in that a plaster or masonry samples must be prepared, each test usually takes about 10minutes to undertake.
Free moisture within the sample reacts with the reagent in the sealed vessel to produce acetylene gas and pressure rise within the vessel that is proportional to the amount of moisture. The moisture content value is then read directly from the calibrated integral pressure gauge.
Additional information on this instrument is available in the BRE Digest 245.
Optical Boroscope: Our Surveyors use these instruments to view confined spaces such as cavities to ascertain the condition of the cavity wall ties, and for inspecting under floor voids, the boroscope is an optical device consisting of a rigid or flexible tube with an eyepiece at one end, an objective lens the other linked together by a relay optical system in between.
The instrument has optical fibres used for illumination of the object to be viewed, a very useful instrument indeed!
Specialised Metal Detector: There are two problems with corroding wall ties. The ties can corrode in the cavity and break such that the outer and inner leaves are no longer tied together. If this occurs, there is a distinct risk of the outer leaf collapsing, especially under high winds which cause suction on the face of the wall.
The more common problem is when the part of the tie embedded in the outer leaf corrodes. This tends to occur on south and west facing elevations which are exposed to driving rain and which are often wet. Rust occupies a greater volume than the original steel and therefore the expansion of the tie in the bed joint forces it to crack. Cracks running along the bed joints, every 450mm up the wall, are a definite indication of wall tie corrosion. In severe cases we have seen the outer leaf being lifted by about 50mm at roof level.
A wall tie report comprises detecting the locations of wall ties using a specialised metal detector and then either removing a brick or the mortar or drilling a small hole and using a boroscope to examine their condition. If the ties are corroded or if there are insufficient ties, our report will recommend a suitable type of replacement. Corroded ties will need to be cut out of the outer leaf to prevent further cracking, if the volume of the metal ties is such to cause cracking of the mortar bed joints, it is therefore essential to have the cavity wall ties inspected by a specialist company, such as H2O Remedial Services who can provide insurance backed guarantees on cavity wall tie replacement systems.
Hydrajaws Proof Testing Rig: These instruments are used to proof test stainless steel remedial cavity wall ties and anchors, etc, our proof test meters range from 0 – 5kN, records of the loading achieved by each tested replacement cavity wall tie are made along with a log of the tie location.
Laboratory Analysis Service: We have access to a Laboratory whereby in depth testing of samples of plaster, brick, timber, mortar etc, can be sent in order to establish salt contents, type of salts present, amount of salts present, moisture content levels, hygroscopic moisture contents, timber treatments used, etc. This information is invaluble to establish the cause of the problem, useful indeed, if on site testing proves to be inconclusive.
AutoCAD Drawings: In order to illustrate our proposals in picture format, we take the time to produce detailed drawings using AutoCAD, thus providing the proposed plan layout, highlighted treatment zones and cross sections etc, all part of the professional service we deliver to our valued customers.