Asking who is using tape, and how that tape is being used (oh and incidentally, how it is performing), is one of the $64,000 question in homebuilding right now. We’re going to try and tackle these questions in the months to come, but before we begin, a review of tape and its many possible locations – and jobs – in the home is in order.
When it comes to air sealing, tape faces a vast playing field full of competitors.
To deliver a healthy, high performance home, the home’s envelope must be secured against water, air, vapor, and thermal intrusions. Narrowing our view to controlling air flow, pernicious leaks tend to occur around windows, doors, and through outside wall penetrations, as well as at connections between attic, crawlspace, or basement. Common penetrations that allow pathways, or bypasses, for air to travel in at will involve ductwork and plumbing chases, recessed light fixtures, and wiring penetrations at top plates, floor decking, and bottom plates of the wall.
So what agents do we call upon to mercilessly seal up holes and seams? Besides tape, there’s a litany of characters, including:
- Spray foam
- Backer rod
- Sheet goods (plywood, drywall, rigid foam insulation)
- Sheet metal (typically used in combination with high-temperature caulk for sealing high-temperature components, like flues and chimneys)
- Polyethylene plastic
- UL181 or foil-faced tape
Looking for the best real estate for your tape? It still comes down to location, location, location.
There are many kinds of construction tapes because there are many carriers (backing) and tons of adhesives, including rubber, solvent rubber, hot melt, acrylic, butyl, and assorted varieties within each of these broad categories. Traditionally, construction tapes come in three main flavors: rubberized asphalt, butyl, and acrylic. Rubberized asphalt tapes can double as flexible flashing, and are frequently found flashing windows. Butyl tapes can be found in numerous sealant applications, including sealing sheet metal joints, acting as a waterproof repair, or serving as flashing. Acrylic adhesive tapes also perform a variety of jobs, from taping housewrap to offering high-grade air sealing on OSB sheathing. (For an excellent discussion and field test on tapes, please refer to Martin Holladay’s “Backyard Tape Test,” Fine Homebuilding April/May 2013.)
One roll of tape will not resolve all your problems. Tapes make use of sealants and adhesives, and those sealants and adhesives rely upon surface chemistry to successfully “stick” one material to another to make a barrier. Unlike weatherlapping and mechanical fastening, the quality of the bond or “stick” is dependent on the nature of the underlying materials, as well as the conditions of application. Temperature, regional weather conditions, exposure of the home, and builder preference also dictate choice in tape. This means deploying several kinds of tape across a home, dependent on location and desired job. One builder may use polyurethane spray foam insulation (SPF), which acts as in integral air barrier for home sealing, and not need tape at all on this air barrier detail. However, that same builder may find the most important use of tape as their weather barrier, using flexible tape on window pans for a good drainage assembly. Another builder may rely on tape extensively: to seal air and vapor barriers at seams, to the floor, to wood and around penetrations, and to flash windows and doors and drainage planes. So tape can legitimately be found performing inside, outside, at the slab, holding down housewrap, or surrounding wiring penetrations.
We’ve briefly met tape in all of its variety and careers. Next, we’ll take on a regional look at what builders are finding with tapes onsite.