Frequently Asked Questions
Accessories
Attachment of roller shades to the interior surface of vertical mullions will not void Tubelite’s product warranty. It is advised that the additional load be considered when evaluating the structural capacity of the storefront or curtainwall system. In general, as long as the weight of the shades is not excessive, and as long as they are not cantilevered to the inside, the attachment does not result in any significant change to the requirements of the system.
Storefront and curtainwall drain water differently. Storefront drains water down the vertical mullions to the sub-sill or sill flashing. Tubelite storefronts are designed to be used with our extruded and thermally broken sub-sills, and do not require brake metal flashing.
Tubelite considers the use of flashing beneath storefront products as unnecessary. All storefront systems are tested for air, water, structural, and thermal performance without sill flashing; and thus, it is not considered necessary to meet performance requirements. Flashing, when included, should be considered as part of the surrounding condition for aesthetics or function, and should be carefully detailed and integrated to the storefront system to prevent compromising the system’s performance.
Properly installed, curtainwall does not require flashing underneath the frame. Curtainwall drains water from each lite at the horizontals and water stays out of the verticals. Because of this, very little water weeps from the curtainwall directly onto the substrate beneath.
Tubelite considers the use of flashing beneath our curtainwall products as unnecessary. All curtainwall systems are tested for air, water, structural, and thermal performance without sill flashing; and thus, it is not considered necessary to meet performance requirements. Flashing, when included, should be considered as part of the surrounding condition for aesthetics or function, and should be carefully detailed and integrated to the curtainwall system to prevent compromising the system’s performance.
Head receptors may be used with curtain wall, but it is done for cosmetic purposes only and is considered unnecessary. The design of curtain wall does not allow for loading to be carried through a snap-on cover, nor can it be carried through a head receptor. Standard anchoring is still required. When a head receptor is used, there is additional coping of the receptor is needed around the mullion anchors using either F/T, or standard head and sill anchors. There are often easier, cleaner ways to achieve the same objective. Sealing conditions also should also be reviewed.
The use of side blocks for Tubelite’s 400 Series Curtain Wall is unnecessary for it to function as intended and is not included in standard pricing. Glass shift has not been observed, either in the field or in laboratory testing.
We do not object to them being used if the client wishes to add them. Because all projects are unique in their requirements, conditions may exist that would justify their use such as shop-glazing a system, or shifting due to anticipated seismic events.
There are two options from 400TU curtainwall, P4628 (EPDM) or P4629 (silicone). These options could be adapted to the 400SS curtainwall. For other 400 Series systems, consult the installation instructions for these components.
Aluminum Finishes
Visually, there typically is not much of a difference between Class I and Class II clear anodize. The difference is in the performance:
- Class I is a high-performance finish used for exterior building products that must withstand continuous outdoor exposure and high traffic. It also is more resistant to salt spray.
- Class II anodic coatings are recommended for interior applications or light exterior applications receiving regularly scheduled cleaning and maintenance such as storefronts and entrance ways.
Another difference to keep in mind is that Class I has a dry film thickness of at least 0.7 mils, while Class II can range between 0.4 to 0.7 mils. The two coatings can be nearly identical in thickness, or Class I can be up to twice the thickness of Class II.
Depending on the alloy, the finish thickness can have a significant effect on the color and brightness of clear anodic films. For 6063-T6 alloy, the visual variation between Class I and Class II is minimal, and unlikely to be detected by the casual observer.
No. Aluminum should not be in contact with fresh concrete. Plastic shims, caulk, or bituminous paint are all appropriate means of isolation.
Fresh concrete is considered to be concrete that is not fully cured. Curing typically can take up to 28 days. The risk is higher of aluminum corrosion is higher if an accelerant (a chloride) is used in the concrete. Once cured, the concrete is pH-neutral and would pose a minimal risk. The reactive chemicals are then captive in the cement, and would have minimal potential for corrosion. Keeping the area free of moisture, as it should be after installation, helps prevent any potential corrosion.
Contact of aluminum with fresh concrete is known to cause permanent staining of finishes. The pH can be quite high, and contact with fresh concrete can be a problem. There are no known, documented cases where aluminum in contact with cured concrete has resulted in corrosion.
Condensation
The issue of condensation and frost on the interior surfaces of architectural aluminum framing usually arises seasonally when outdoor temperatures reach extreme lows. Thermally “broken” systems reduce the effects of cold temperatures, but high humidity levels found in residential and some commercial buildings can accentuate condensation.
The Fenestration & Glazing Industry Alliance offers information and documents provided by the American Architectural Manufacturers Association (AAMA) to help explain the conditions that cause condensation, and provide information on further reducing it.
ASHRAE 99.6% Heating Dry-Bulb (HDB) Temperature for Major U.S. Cities and State Capitals
This document summarizes the values for major U.S. cities and state capitals that represent dry-bulb temperatures corresponding to 99.6% annual cumulative frequency of occurrence (cold conditions), in degrees Fahrenheit.
View the PDF »
“Understanding Indoor Condensation in Your Home”
AAMA started evaluating the thermal performance of windows and doors in 1972. The first AAMA voluntary standard for thermal performance was developed specifically to measure the condensation resistance of windows and sliding glass doors. Since that time, AAMA standards have evolved to include windows and doors of various materials and types, as well as ensuring that emerging technologies are assessed.
As an association of window, door and skylight manufacturers, AAMA understands that these products enhance the beauty and comfort of your home by providing views, ventilation and daylight. To maximize the enjoyment and realization of these attributes, you should understand how condensation is formed and how it can be minimized.
Read the Article »
Condensation Resistance Factor (CRF) Tool
The CRF Tool is intended to provide general guidance on suggesting a minimum Condensation Resistance Factor (CRF) based on a project-specific set of environmental conditions.
While not an absolute value, the CRF is a rating number obtained under specified test conditions to allow a relative comparison of the condensation performance of the product. It will provide a comparative rating of similar products of the same configuration and permit the determination of the conditions beyond which an objectionable amount of condensation may occur.
Use the Tool »
The humidity level is typically quite high in a pool area (natatorium) and consequently, condensation on doors, windows, storefront and other systems should be expected in months with colder temperatures.
The factors determining the occurrence of condensation are: outside temperature, inside temperature, interior relative humidity, and the condensation resistance factor (CRF) rating of the system.
Thermal doors are recommended for natatoriums for improved condensation resistance. During the cold months of winter, even a thermal door in this type of application may experience condensation in a natatorium.
The best approach to improve condensation on pool area doors is to try to reduce the humidity as much as possible.
Door Hardware
Rim panics were not included in our blast testing because they only latch at the panic location.
In order for the doors to remain blast rated, any hardware substitutions must be evaluated and approved by a professional blast engineer. Refer to the test reports published on our website for blast hardware options.
Rim panics were not included in our blast testing because they only latch at the panic location.
For the doors to remain blast rated, any hardware substitutions must be evaluated and approved by a professional blast engineer. Please review the available test reports for blast hardware options.
Below are Tubelite’s guidelines for door leaf weight when using our P795 offset pivots sourced from Amesbury.
| Number of Pivots | Recommended Leaf Weight Limit (lbs) |
| 2 | 120 |
| 3 | 210 |
| 4 | 240 |
Other
Test report summaries of acoustic tests are published on the Tubelite website, but not all glass types perform equally. It’s impractical to test every possible glass type, so sometimes it’s necessary to estimate. To estimate acoustic performance in storefront or curtainwall, a good general guideline is “glass value minus three.” Take the STC or OITC value of the glass on its own and subtract three for the expected overall performance. For example, since a typical 1” insulated glass unit has a STC rating of 35, we expect the overall value to be 32 when it is installed in framing. When we compare glass performance values with Tubelite’s published test results, we see that the rule holds true with good accuracy. Viracon and other glass manufacturers publish acoustic performance tables that can be helpful for selecting glass to meet an acoustic specification.
Tubelite would be happy to review your application. If you have any questions, please feel free to contact Tubelite’s Engineering Team – Engineering@TubeliteUSA.com
The shadow box area is an aesthetic design feature used to mimic the appearance and depth of vision glass areas in order to provide uniform visual continuity across the spandrel areas of a curtain wall elevation. Unlike typical opaque spandrel glass, a shadow box spandrel feature is an area with clear or tinted glass and a cavity with an opaque finished back pan attached to the mullions.
The basic configuration of the shadow box can present many building envelope design challenges. These include:
- Excessive heat buildup within the shadow box cavity
- Glass breakage due to excessive thermal stress
- Glass distortion or delamination (for laminated glass)
- Heat transfer from the mullion to the interior
- Condensation and moisture buildup in the shadow box cavity
- High air pressure in the cavity and structural stress on the back pan and glass
- High temperature and air pressure differentials resulting in seal failure
- Air/water/dust infiltration due to the venting/drainage scheme
The severity of potential heat gain within the shadow box cavity depends on a combination of many project-specific conditions: the shadow box orientation relative to the sun, the local climate, glass makeup VT/SHGC, the albedo of the shadow box finish and the ventilation strategy used on the shadow box cavity.
There are different shadow box cavity ventilation design strategies that can be used: venting to the exterior, venting to the interior, mullion venting, or non-vented (sealed cavity). Each of these strategies has trade-offs, pros and cons which must be carefully weighed by the designer according to the project conditions.
Due to the unique project-specific conditions of shadow box design, Tubelite is not liable for the design, installation, or performance of shadow box features. The design of the shadow box and the determination of the shadow box ventilation strategy is the responsibility of the architect/owner – even if the system is part of a “Delegated Design” project.
Purpose:
The purpose of this information is to establish Tubelite’s recommendations and guidance on the use of expanding spray foam insulation in and around any provided system. This includes storefront, ribbon window, vent, entrance, and curtainwall systems. This does not address the use of other insulation material.
Foam Types:
Spray foams are available from many different manufacturers and are commonly classified as low or minimal expanding foam, or high expanding foam. They are typically cured by reaction with moisture in the air. The amount of expansion and the chemistry of the product may vary between manufacturers.
Compatibility:
Regardless of the intended application, any spray foam insulation that is to come into contact with any Tubelite provided product should be checked for compatibility. This includes both pre-cure and post-cure condition of the spray foam. Tubelite does not use spray insulation in our product testing, and we do not perform compatibility testing of spray foams. Because of the variety of chemistries that may be involved in these products, end users should verify with the spray foam provider that the use will not affect the aluminum, anodized finish, or other elements of the system with which it may come in contact. This includes PVC fillers, EPDM or silicone gaskets, silicone sealant, backer rod, or other materials provided. Any damage to Tubelite material from exposure to incompatible spray foam will not be covered by Tubelite warranty. All other provisions of the warranty will remain in effect.
Use in Mullion Cavity:
Tubelite does not support the use of any spray expanding foam within the body of the mullion in any location or orientation. This includes jambs, intermediate vertical mullions, horizontals, head, or sill.
Risks of spray foam insulation in mullion cavities:
- Expanding foam may prevent the draining of water within the system, resulting in leaks or
other damage. - Thermal performance can be reduced.
- Preventing moisture from draining can promote mold growth.
- Because many expansion foams require moisture to cure, manufacturers may not recommend the use of the product in a closed cavity such as a mullion. The foam may never fully cure.
Use at Perimeter:
Spray foam is often specified for use at a perimeter condition. It is applied between the framing system and the adjacent wall or structure. Use of spray foam around the perimeter of the framing system is acceptable, providing it is used in addition to backer rod and sealant to improve the performance of the building. The foam must be compressible and not rigid. The same concern over compatibility exists and needs to be evaluated. Additionally, the foam must not fill the mullion, and the expansion of the foam must not dislodge perimeter filler material. Tubelite is not responsible for the performance of the foam in this application. Tubelite is not responsible for any deterioration of the foam due to temperature, humidity, or movement of the framing system.
Please contact Tubelite Engineering with additional questions or concerns.
Engineering@TubeliteUSA.com
Disclaimer: The subject of this information is intended to address common generic conditions or situations. It cannot address every aspect of a given installation or environment. Site specific conditions which may affect the content of this information should be addressed on a case by case basis.
Tubelite tests its curtain wall, storefront, ribbon window, and entrance systems in accordance with industry standards. The results of these tests are published on our website and given in test reports. Some of these reports have expiration dates that have since passed.
Many test laboratories list expiration dates on test reports as part of their own policies, or as a requirement for various certification and labeling programs. Tubelite products are not labeled, and any labeling protocols are not applicable to field-glazed systems. There is no requirement to retest at regular intervals, unless the testing apparatus or procedures change, or the product design or materials change.
FGIA (AAMA) has a statement regarding this. (See below)
Test reports are a historical record of test results on specific test specimens, tested to a defined standard or standards; a “snapshot” of the product at a certain point in time.
Laboratories may include expiration dates on their test reports that reflect their individual policies. These expiration and/or test record retention dates will vary from laboratory to laboratory and test report to test report. As historical records cannot technically “expire”, these dates are arbitrary. In the event that no changes are made to the design and/or construction of the product as documented in the test report, it is the position of AAMA that the test report remains valid as a reflection of the facts as of the date of the test.
Test reports prepared by AAMA accredited laboratories are mandated throughout AAMA’s certification and verification programs and are referenced in its voluntary standards, specifications and test methods. Though some test reports may contain expiration and/or test record retention dates established by the testing laboratory, AAMA does not rely on these dates in its certification and verification programs. For the purposes of certification and validation, a test report is considered valid for the duration established by the requirements of the applicable certification or verification programs. For example, AAMA/WDMA/CSA 101/I.S.2/A440 test reports are mandated to include test dates, report dates and a test record retention date
Thermal Performance
Brake metal flashing can be used on the exterior side of Tubelite storefront or curtainwall to prevent water from draining directly onto brick or masonry.
Brake metal flashing should not continue under the storefront or curtainwall such that it bridges a thermal break or interferes with the perimeter seal. Be careful to avoid running brake metal flashing all the way under a window frame or it will cause condensation problems. It also is more prone to leaks at the seams and splices.
Tubelite’s storefront and curtainwall systems are tested without flashing. For our storefronts, we recommend using our extruded and thermally broken sub-sill. This allows the system to drain water effectively, while maintaining high thermal performance. Our curtainwall products drain at each horizontal and have no need for sill flashing underneath the frame.
Water/Air Penetration
Tubelite’s curtain wall systems must be installed with the exterior perimeter seal at the shoulder of head, sill, and jamb members where they meet the adjacent construction. This seal must be in place for a field test to be valid. Size sealant joints per installation manuals and approved shop drawings. Interior seals and additional exterior seals are considered cosmetic and not required for curtain walls.
See the example image below.
Tubelite’s ribbon window systems must be installed with both the exterior and interior perimeter seals at the outer and inner edges of the head, sill, and jamb members where they meet the adjacent construction. Sealant joints should be sized per installation manuals and approved shop drawings. To achieve published air and water infiltration performance and for a field test to be considered valid, both interior and exterior seals must be in place as shown in our installation instructions and the example below:
Tubelite’s exterior storefront systems must be installed with both the exterior and interior perimeter seals at the outer and inner edges of the head, sill, and jamb members where they meet the adjacent construction. Sealant joints should be sized per installation manuals and approved shop drawings. To achieve published air and water infiltration performance and for a field test to be considered valid, both interior and exterior seals must be in place as shown in our installation instructions and the example below:
Storefront doors on upper floors generally are discouraged due to the potential air and water infiltration problems that may result from higher pressures and exposure to rain on upper floors. Storefront doors are designed to be accessible and handle high traffic, but there are trade-offs that limit the ability to resist water and air infiltration. Buildings should be designed with overhangs and awnings above the entrances to limit the amount of contact with water.
Outswing storefront doors are better at resisting water infiltration than inswing doors because any weather-sweep on the threshold will help direct water away from the building.
Most storefront entrances are not designed, tested, or rated for water resistance.
They are designed for high traffic and accessibility. There are trade-offs when designing for water resistance that reduce an entrance’s accessibility and ability to handle high traffic. This is not unique to Tubelite—you will find that similar products from our competitors are also not rated for water resistance.
To avoid water issues, commercial buildings are typically are designed with overhangs or awnings to protect the entrances from rainfall.
Tubelite’s narrow, medium, and wide stile standard entrances use the same fundamental design. The difference between them is the widths of the stiles and rails used in their construction. All other aspects of the doors remain the same. To verify the performance of the door design, narrow and medium stile doors were tested. Standard wide stile doors have the same design; therefore, the test results are valid for them as well.
Tubelite’s medium and wide stile thermal entrances use the same fundamental design. The difference between them is the widths of the stiles and rails used in their construction. All other aspects of the doors remain the same. To verify the performance of the door design, medium stile thermal doors were tested. Wide stile thermal doors have the same design; therefore, the test results are valid for them as well.
Tubelite’s narrow, medium, and wide stile monumental and standard entrances use the same fundamental design. The difference between them is the widths and wall thicknesses of the stiles and rails used in their construction. All other aspects of the doors remain the same. To verify the performance of the door design, narrow and medium stile standard doors were tested. Monumental doors have the same design; therefore, the test results are valid for them as well.
Each of Tubelite’s curtain wall systems has multiple options for mullion depths. All mullion depths in each system have the same fundamental design, the only difference being the size of the backmember used. All other aspects of the framing system remain the same. The tests outlined in each system’s test summary were performed on one mullion depth to verify the system’s design and its ability to meet air and water infiltration requirements. Testing all system depths is not practical or warranted. Because the other mullion depths use the same glazing, pressure plates, water dams, and gaskets, the air and water infiltration test results are valid for them as well. Thermal performance is addressed in separate reports.
Each project must be evaluated on a case-by-case basis. The structural performance of the curtain wall is dependent on the backmember depth, reinforcement, and anchoring. Framing for every project should be evaluated to ensure that it meets building code requirements, which will vary from project to project.
Tubelite has not tested any of our products for smoke or fire resistance.
The maximum recommended height of all exterior 2″ x 4-1/2″ storefront frames is 12 feet. The maximum recommended height of exterior 2” x 6-1/2” storefront frames is 14 feet. These are the maximum heights at which these systems have been tested for water infiltration resistance. Exterior storefront frames exceeding these heights have an increased risk of leaks. A curtain wall system should be used for exterior frames taller than 14 feet.