If you’ve been reading my blog for a while, you know I’m a big fan of Siga’s water and air sealing products, especially their tapes. Recently they came out with two products that substantially reduce the time it takes to flash window rough openings.
Siga’s recommendations for window water and air sealing used to involve several products and a lot of complicated tape cuts and layers to meet their requirements per their window flashing guide. The following photos are from my recent Barndominium project.
The two window rough openings in the photo above took nearly two hours to achieve Siga’s recommended water and air sealing requirements. The updated process using the Rissan 430 would have taken less than half that time.
With the new system, all I need are the corners and the Rissan straight tape. Rissan 430 Grey is a vapor closed exterior straight tape designed with window water and air flashing for rough openings in mind. The split-back tape is available in both 6 and 9-inch versions, the 6-inch would be ideal for 2×4 wall assemblies, and the 9-inch is what I would use on 2×6 walls or when a wood window buck is part of the window rough framing assembly. The straight tape is installed on the bottom sill before the corner tapes are placed. The tape should be cut long enough so that it fills the entire bottom sill without extending up the vertical window framing. The tape is applied by peal half the backer, position and use hand pressure to stick in place, peal the other half of the backer and fold around the 90° corner of the opening. Finish wetting* the tape by using a squeegee or roller.
Rissan 430 Grey Corner is a pre-formed inside corner tape. It fits perfectly in the inside corner of a window rough opening. The corner also features a split backing that allows for easy placement without having the corner adhesive stick to your fingers during placement. I found it easier to stick the inside corner first, then remove the outside face backer, adhering to the wall sheeting or window buck assembly. Wet* the tape by pressing firmly using Siga’s squeegee or a roller. I found the tape installs easier than other sill protection systems, there was no bunching of the tape in the corner and no “fish mouths” to direct water behind the tape, which can be common with other systems.
Finish the taping by installing tape between the wall sheeting and window rough opening framing along the sides and top to assure a good air seal at those connection points.
Nether of the 430 tapes need a primer, even when adhering to OSB. The low limit application temperature is 14°F. The perm rating of the tape is .046, below the level of polyethylene sheeting, commonly used as a vapor barrier in cold climates.
I prefer to install products as a system, for instance, if I’m using Huber’s Zip Sheeting, I prefer to use their tapes and other product accessories to complete the installation. This might be an exception; I’m so impressed with Siga’s corner and straight tapes for window water and air sealing, it might become my new assembly no matter what WRB manufacturer is used.
Here is a link to Siga’s installation instructions for the new Rissan 430 tape.
A second link to Siga’s technical data sheet for the Rissan 430 tape.
*”wetting the tape” is the process of having the tape’s adhesive fully adhere to the substrates the tape is being applied to. Tapes need pressure along their entire surface to correctly and completely adhere to the surface. Simple hand pressure is usually not enough, a J-roller or squeegee is typically required.