A look at what makes flashing tape so sticky and why the way you install it determines how well it stays stuck.
Adhesion is what makes the tape stick to the sheathing. Cohesion holds the adhesive together and affects its elasticity, which is what allows it to resist separation from the substrate when a force is applied to it.
But how well these forces work in pressure-sensitive flashing tapes depends on jobsite conditions and the care with which the tape is installed. Flashing tapes that use a pressure-sensitive adhesive literally require you to press on the tape to activate the adhesion and cohesion. Pressure is best applied to tape using a J-roller, a plastic squeegee, or similar tool to mash the tape into the surface [2].
The other critical variable is the temperature range during installation. On a vertical wall the tape might stick temporarily, but without pressure it will never get a good bond to the substrate—even gravity will be enough to cause the tape to peel off.
But heat alone is not enough for pressure-sensitive tapes: They need to be applied using pressure to wet the adhesive into the surface. On a hot, sunny roof deck, for example, you can sometimes see tape or peel-and-stick membrane that has started to slide, especially if workers have stepped on it or stacked heavy roofing bundles on it. Adhesive strength varies, depending on the viscoelastic properties of the adhesive chemistry in the tape.
Butyl, for example, might have more flow initially, so it can achieve higher adhesive strength right up front, but that might degrade over time. An acrylic, by contrast, tends to build adhesive strength over time because it wets out more slowly. RSB Roofing. Hi I would always use lead flashings. It has no resale value. So you have no worries material to be stolen. I've got a roofer in right now. The problems I had are that the lead roofing above my bay window approx 3m x 0.
Hi, I had a wee bit of damp at the top of the chimney in my back bedroom I live in a bungalow. I looked at my chimney and Hi, I had a new roof installed a year ago. It is an artificial slate roof. Looking at it, there is no lead flashing. Does the flat roof of a kitchen extension need to be lead flashed into the adjoining main wall? Does it need to be lead or is Alco Ask a tradesman. EDIT: Thank you all for your answers! We went with lead :. Like 3. Like 2. Like 0. Blank cells indicate that through March 28, , the tape is still adhered to the substrate well enough to support the weight when loaded.
This shed is leaky regarding both air and water , with temperature and relative humidity pretty close to that of the true outdoors. Graph 1 shows how all the tapes held until we moved them from the sheltered workshop to the outdoor shed.
In past work adhering Pro Clima Tescon Vana tape with its primer to both rough-side OSB and masonry such as concrete block and brick, the primer and tape could only be separated by essentially ripping apart the substrate of the tape, or both. There was an incredibly strong bond with the primer. Therefore we were surprised that this product did not perform as well in our latest testing.
Principal David NiCastro, P. Admiration and flattery? Wingnut wonders never cease. Incidentally, I took the following photo in mid-May There were only eight test samples still hanging in there. Published June 10, Permalink Citation. Yost, P. To post a comment, you need to register for a BuildingGreen Basic membership free or login to your existing profile. April 1, - pm It's great to see these types of studies happening.
I'm curious your thoughts on the performance difference from Holladay's article where he said the "zip system tape did not perform well on OSB. Explore the archives. Skip to main content.
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