Rilem Tube Extended

By:  Gil Castonquay    

In this segment we'll focus on the "Rilem Tube" test method.  If this were a full length article, we certainly would get into a more detailed background as to how the test came to be, such as how RILEM originated in France and is actually an acronym for Réunion Internationale des Laboratoires et Experts des Matériaux, and is conducted per the RILEM Commission 25, PEM, Test Method 1154, but, for the purpose of this blog, for brevity sake, we'll just cover some of the high points to provide a brief overview as to how and why this test method, this tool, should be a part of your diagnostic approach tool bag when evaluating building enclosure performance.


When faced with the challenge of identifying causes or sources of water intrusion in a building enclosure, building scientists/design professionals performing the forensic analysis have a multitude of diagnostic methods to consider.  Methods such as AAMA 501.2 "hose testing" with a single calibrated nozzle; ASTM E 1105, which utilizes a calibrated water spray grid to cascade water onto larger sections of the building enclosure; and ASTM E 514, which is primarily designed for masonry and determining the water penetration over a larger wall surface area.  For the most part, these test methods are better suited for testing larger sections of the building enclosure, can be quite costly, are time consuming, and require special provisions for isolating out various building systems/components. For the purpose of isolating and focusing on the performance of much smaller components and building material interfaces, the lesser known but highly effective water head pressure test, in this case the RILEM Tube method, should be considered as a diagnostic tool.  

In performing a bit of research, I came across a fair amount of good information regarding the use of the Rilem Tubes as a tool for evaluation of water penetration into brick and masonry wall assemblies.  For years, our firm has utilized Rilem Tubes to evaluate the water permeance of brick, and especially to determine the rate of water penetration at those pesky brick-to-mortar interfaces where separations as small as a few thousands of an inch will allow water to seep through the brick wall assembly. 

The test is basically conducted by securing a RILEM tube via putty or gunnable sealant to a vertically or horizontally situated building material, filling the RILEM tube with water, and then timing the rate of water height reduction within the Rilem Tube.  Based upon the rate of water head height reduction within the tube, a rough calculation can be performed on the rate of absorption or permeance through a particular component.  Also, a rough calculation  can relate the height of the water head to a theoretical wind speed.  For example,  a RILEM tube filled to the 3.0 ml mark on the graduated vertical tube is roughly equivalent to a 70 mph wind.  I say "roughly" because, for obvious reasons, the static water head provided by having a tube in place does not accurately simulate the effects of wind-driven rain dynamics and other factors that affect the building enclosure.   
Some of the RILEM Tube method Pros and Cons are as follows:

Pros

• Rilem Tubes are inexpensive, much less expensive than larger, more specialized testing equipment and methods, such as but not limited to AAMA 501.2, ASTM E 1105, ASTM E 514.  
• It is an easy test to run
• It only requires one person
• No specialized equipment other than the Rilem Tube itself, a bottle of water, plumber's putty or gunnable sealant is required.
• Basically, (and I mean basically) replicates water induced water penetration via head pressure, which is roughly equivalent to a wind pressure or speed.

Cons

• Must be understood that it is not an equivalent method compared to some other methods, such as ASTM E 514 test method
• Even though it's easy to run, the person performing the test must have the experience to exercise proper judgement in determining the applicability of the test method and results in a particular situation
• The  tube can sometime be difficult to adhere, and care must be taken to select a putty/adhesive that is watertight and will not stain the cladding

As stated earlier, the RILEM Tube method is largely used to evaluate masonry wall systems, but did you know that Rilem Tubes can also be used effectively on other building materials, such as but not limited to:  stucco (see attached video clip example), EIFS, window joinery, sealant to cladding joint interfaces, and all sorts of other building components and interfaces.  In the attached video clip we're demonstrating the use of a RILEM Tube to determine the rate of water penetration at a crack in stucco cladding located at a window corner.  Obviously, it comes as no surprise that a crack in stucco as wide as that shown here would allow water to penetrate through the stucco.  However, use of the RILEM Tube on this project provided a quick and easy method to isolate out causes or sources of water intrusion to the interior space without the need for more costly and time consuming isolation via tape and plastic sheeting, and having to run hoses and set up calibrated water spray equipment.   

In another segment, we'll address another form of water head pressure testing, what we've dubbed as "resevoir testing", which was based upon the RILEM Tube procedure, but allows for more flexibility in applying a water head pressure to various wall components. 

References:

• ASTM E 514
• Josheph L. Crissinger "Measuring Moisture Resistance to Wind-Driven Rain Using a Rilem Tube", RCI Interface Magazine, November 2005