adhered in hot asphalt applied in the EVT range at a rate of 20-40 lbs/sq. Membrane: (Not for use over USP Type IV or VI Felt) One ply of USP APP 160M, SafeWeld 180M APP, SafeWeld 180FR APP, DuraWeld 4M APP or DuraWeld 4M FR APP, heat welded. Or (Not for use with APP ply sheet) One ply of USP Mineral Cap Sheet adhered in hot asphalt
1. Equiviscous Temperature (EVT) is the temperature needed in the mop bucket or mechanical spreader in order to have the proper asphalt consistency or viscosity to ensure the correct amount of asphalt is applied to the roof. 2. All products meet or exceed the requirements of ASTM D 312 (Physical Requirements of Asphalt Roofing).
When the asphalt is hot enough, it will melt the backside of the modified sheet and provide a monolithic roof system. Without ensuring that the asphalt is in the proper EVT range, you could end up with asphalt that is too cold. This results in too much asphalt, which can mean: Slippage of plies. Slumpage of asphalt. Increased stress on plies.
Exposures during Hot Asphalt Roofing Jobs Introduction Controlling worker exposures to asphalt fumes and particulates should be a priority on every hot asphalt roofing ... temperature," or EVT, and the application temperature target is expressed as EVT ± 25°F [EVT ± 14°C]. EVTs can vary. On jobs involving hot application of other asphalt
AC® products with hot asphalt has changed in two important ways. First, the asphalt shall be applied at a temperature approximately 60º F (≈15ºC) to 70ºF (≈20ºC) lower than the inter-ply hand mopping *EVT. Second, the temperature of the asphalt at point of contact with these AC® products shall not be greater than 390º (≈ ...
The previous examples dealt with asphalt being applied at temperatures too hot (viscosity too low) to adhere to desired level of adhesion. In the case of modified bitumen, problems can occur as a result of the asphalt not being hot enough if applied at the EVT recommended for built-up roofing applications.
The proper temperature to heat asphalt before hot mopping is referred to as the equiviscous temperature (EVT). At this temperature, the asphalt is viscous enough to be mopped out evenly, but not too thin that it runs uncontrollably. This viscosity is measured in centipoise (cP). The ideal viscosity for hand mopping is 125 cP.
3. The asphalt in a tanker should be kept at or below its Final Blowing Temperature. Should it become necessary to heat the asphalt above the FBT in order to get the right EVT on the roof, the period should be limited to 4 hours, or better still, transfer the asphalt from the large tanker
and type and condition of the heating equipment. Maintaining asphalt temperatures within the EVT range may be difficult when the roof is applied in cold weather. Rapid cooling of the hot asphalt may result in poor adhesion, voids in the asphalt layers or excessive and nonuniform applied thickness between the layers of reinforcing material.
Asphalt should always be used at the lowest practicable temperature given the specific application. The proper temperature for BURA application is the equiviscous temperature (EVT), plus or minus 25°F. On a job the EVT is measured in the mop cart, bucket, or mechanical spreader just prior to application to the substrate.
Asphalt in a bucket being read-ied. The asphalt was hot and at its recommended EVT. Mopping the RedLINE expansion joint down. Note that both the base plies and the underside of the RedLINE are coated with asphalt. Joint waterproofing is laid out along the roof expansion joint. Note the roofing base ply(s) have already been installed and cut ...
voids, into the hot asphalt (within ±25°F [±14°C] of the EVT) applied just before the felt at a nominal rate of 23 lb/100 ft2 (11 kg/9.29 m2), over the entire surface. Installation over porous substrates such as roof insulation may require up to 33 lb/100 ft2 of hot asphalt (16 kg/9.29 m2). Surfacing
POINTS TO NOTE WHEN MOPPING RedLINE IN HOT RUBBERIZED ASPHALT 1. Ensure that the RedLINE material fleece is dry. If by chance it is exposed to moisture, dry it out prior to application either by hot air drying or laying it out in the sun. 2. The Hot Rubberized Asphalt used must be at its EVT when applied to the RedLINE fleece. 3.
† Typical EVT range at 125 cps and 75 cps † Manufacturing date This material will comply with ASTM D312 specifi cation for Built-Up ... are fused together using hot-mopped asphalt to create a monolithic barrier. Because traditional single-ply systems are laid loose, they require ballast or
into the hot asphalt. Asphalt temperature should be at the Equiviscous Temperature (EVT), ±25°F (±14°C), at the point of application. All felt edges shall be well sealed. The asphalt shall be applied just before the felt, at a nominal rate of 23 lb/100 ft2 (11 kg/9.29 m2). When applying over insulations,