Home » Photos » In the Construction Testing Laboratory
Before building the actual building, the best projects include the construction of a project specific mockup for testing. Here is a look inside some of the best labs in the USA.
VIew of Architectural Testing, York, PA.
Architectural Testing can accommodate many large mockups. Mockups are portions of a building that are built first in the lab as a proof of concept.
Mockups are often built against a testing wall. These steel testing walls are about 60 feet high.
Many mockups need a steel skeleton upon which they are built. The structural steel is welded to the test wall.
Tall steel columns are stood up and welded in place. THis will become the internal structure for a new mockup. All mockups are custom and unique to the project.
Large mockups are usually outside, and they are built in all seasons. These men are preparing a mockup in high winds and very cold weather. But the flag is inspiring them to forge on.
When working with structural steel at heights, a crane is used to steady the steel while the workman welds from a boom lift.
This is a view behind the testing wall. There is another testing wall just behind it. The testing walls are subjected to intense pressures during testing, so they must be super-strong.
This is the beginning of our skylight mockup. The lab has built the heavy steel frame. Now workmen are infilling the vertical walls with metal studs and gypsum sheathing.
Another view of the test chamber under construction. Gypsum sheathing is already installed on one wall. The end wall studs are ready for sheathing.
Stud framing for the tall rear wall is built on the ground and will soon be fastened in place.
Workman preparing the endwall for sheathing.
View inside the test chamber. The plywood end wall was constructed by the lab.
Outside the test chamber, the blank wall with the chamber door is seen. The lab has painted it to protect it from the punishing test sequence to come.
Now all three walls have been fitted with studs and sheathing.
The top of the wall has a strip of plywood sheathing for better attachment of the panels. Then the sheathing is covered with rubberized membrane at top and bottom edge and Tyvek along the field.
The workmen carefully apply the peel and stick rubberized membrane to the top of the wall. This area is where the skylight will anchor.
The workmen are bedding the edged and overlaps of the rubberized membrane in sealant for extra weather resistance.
Installing the rubberized weather membrane must be done carefully so that it is as smooth as possible with no gaps beneath it where air or water could penetrate.
This is me, Mark Meshulam. On this project, I am consultant to architect DiDonato Associates in Buffalo, NY. My job is to observe and document all mockup installation work and testing.
Where membrane sections overlap one another, careful detailing and sealing are essential.
Here, all three workmen from the panel installation subcontractor are detailing the interface between TYvek and bottom membrane.
Sometimes to do the job right, you have to lay on the ground. This reminds me to send a shout out to all hard working construction workers who endure physical hardships such as cold, noise and wind on a daily basis. These men and women deserve recognition for their hard work.
With hat channels (the silver horizontal strips) installed, now the panels can be installed. These panels are called composite panels.
Composite panels are about 1/4" thick. They have outer skins of thin aluminum and a core of polyethylene, similar to the material plastic milk bottles are made from. The panels are made from large flat sheets by a local fabricator to fit the project.
Galvanized hat channels are cut with a grinder.
A skilled fabricator of composite panels can make them in all shapes and sizes, even corners. Here the workmen are fitting the corner panel.
Top view of the top of a composite panel seam. The edges of each panel are folded back to create the appearance of depth at the seams. The panels are fitted with aluminum extrusions that allow the panels to be hung onto a receiver system. The receiver system has a slot for the insertion of a vertical strip of panel. This strip is seen when looking into the panel seam, giving a finished appearance.
The panel crew with general contractor and yours truly.
View looking down at our area of the lab from the top of the test wall.
View looking down at our mockup from the top of the test wall.
I placed a time lapse camera at various places during the work. Here, the camera is mounted to the top of the tall testing wall.
Now the skylight team is hard at work. One of their first tasks is to assemble the rafters. The assembly consists of a long rafter mitered to a short rafter.
The rafter assembly is heavy and unwieldy, so a "lull" is used to raise and lower it in position. A lull is a combination of a crane and a fork lift.
The workmen already installed clip anchors at the sill, so the rafter assembly can be readily bolted to it after it is lowered in place.
Workman receiving and positioning the short rafter end.
Workman retailing the sill of the skylight after horizontals are installed. That's one of my cameras in the foreground. These workers had no privacy.
A big wind gust blew this amera over even though it was on a sturdy tripod. The impact to the camera was fatal. And the testing has not yet even started.
Workman fitting a piece at the bottom of the skylight. This piece will connect the panel below to the skylight above.
Workmen fitting the bottom pieces at the corner so they form a miter (a 45 degree cut on each piece that fits together like a picture frame corner).
The glass has arrived. The glass truck has come from Minnesota to Pennsylvania to bring the mockup glass. Workmen prepare to unload the crates.
With a glass crate open, the workmen attach a "cup rack" with multiple suction cups to the glass to make it ready to be lifted into position with a crane.
This skylight structural silicone glazing on the horizontals. This means the glass is glued to the frame behind it with no mechanical fastening. The structural silicone was just applied to the purlin (the horizontal frame). The glass will be pressed into it. The structural silicone takes three weeks to fully cure.
Here the first piece of glass is being flown to its location on the skylight as the workmen await.
The cup rack, with four suction cups, can be seen holding the glass. The crane operator carefully maneuvers the glass so it gently lands in the desired position. Workmen communicate with the crane operator with hand signals.
The long awaited moment when the first lite of glass is in place. It is an insulated unit with tempered glass on the exterior and laminated glass on the interior. The laminated glass has a frosted color with silk-screened grid lines. The frosted finish will diffuse the light and make the interior space very pleasant. The grid pattern emulates the existing skylight translucent panels that failed and are being replaced.
Workmen setting heavy glass with a crane and cup rack.
Workmen receiving and guiding the glass into place.
Workman sealing along the ridge of the skylight. He is using a motorized caulk gun.
Workmen aligning the bottom edge of the glass before lowering the top edge into position.
Workmen work from both sides of the slope to attach pressure plates and covers on vertical seams.
Now we are ready to start testing. The spray rack is attached and beneath it the skylight has been covered in plastic. This plastic is called a tare sheet. It is sealed at all edges of the skylight, then the first round of air readings are taken.
Taking air readings. Air is evacuated from the chamber until a pressure difference of 6.24 psf of pressure is achieved between outside air and inside the chamber. Then a flowmeter is used to measure how much air is removed from the chamber in order to maintain that pressure. The reading is recorded.
The digital gauges on the lab equipment measure chamber pressure in psf (pounds per square foot) and air flow in cfm (cubic feet per minute).
After the first set of readings, the plastic tare sheet is removed. Then the readings are taken again. The difference between the initial and current air flow readings are attributed to the skylight. If the airflow measured through the skylight is less than what is allowed, then the test is a PASS.
View inside the test chamber.
Another view inside the test chamber.
This is a diagnostic smoke test. One of the initial air test readings seemed high (for the chamber portion) so this was done to troubleshoot the chamber.
The spray rack is lifted in place in preparation for the water testing.
Witnesses generally attend mockup testing. Here we have representatives from the owner, architect, general contractor and curtainwall supplier.
Some days at the lab are inclement to say the least. On my first trip I was underdressed and froze. This time I have layer upon layer and am generally ok with the wind, rain and cold bombarding me.
The static water test involves spraying the exterior of the skylight while pulling 15 psf of pressure from the chamber. This will cause the skylight to suck water through even the tiniest of holes.
The spray rack is pouring the equivalent of 8" of rain per hour onto the skylight for 15 minutes. This is a severe test.
Now we will be spending time inside the chamber during the water testing. The glass looks nice and for once we are out of the weather.
Witnesses and lab tech are inside the chamber during the water test, looking for leaks.
Something doesn't look quite right and we take turns taking a look.
After passing the static water test, we move on to the dynamic water test. Instead of pulling pressure from the chamber, we use an airplane engine to propel the water spray at the skylight. It makes a lot of noise and shakes the skylight. This test also runs for 15 minutes. Witnesses are inside the chamber during this test. For first-timers, it can be memorable having that propeller cranking away so close to you.
Even though a water test is going on, there is time for a selfie.
Having a good flashlight is important when looking for leaks. This one is my pride and joy, 940 lumens! Do not look into it if you value your eyes.
When observing testing, I usually have a camera, flashlight, drawings and a phone in close reach.
With water testing completed, structural testing is next. The chamber is pressurized up to design pressure, both positive and negative while deflection readings are taken. Here the lab technicians rig the structural test gauges.
The gauges used in a structural test are dial indicators with an indicator needle that stays in its highest reading position. Before the test, all dial indicators are zeroed so the readings are accurate.
To measure the deflection of one framing member, three dial indicators are used. One is at the middle and one is at each end. After the pressure is released, the technicians take the difference between readings of the middle gauge and the average of the end gauges to get an accurate reading. If the deflection less than the length of the span of the piece divided by 180, it is a PASS.