Tape life expectancy ( air sealing & flashing tapes)
roygoodwin
| Posted in Green Products and Materials on
Maybe I’m not asking Mr Google the right question, but I’m not finding anything on the life expectancy of air sealing tapes & flashing tapes. I’ve seen the backyard tape test, but that doesn’t answer the question of how the tapes will be performing in 20+ years. Any suggestions on where to look or particular tapes to recommend ?
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Nobody knows. A lot of Building Science involves trial and error and field analysis which may involve ripping open wall assemblies 30 years later to see what transpired. Who knew that Tyvek installed in the 1970's & 1980's would get attacked by the oils in the cedar siding causing the Tyvek to disintegrate? It took ripping open a wall in 2013 to see that this phenomena took place.
The consensus states that QUALITY building tapes like SIGA and others should last a lifetime (100 years) but as you and I know, SIGA tape hasn't been on any buildings for 100 years as of yet so we can't say whether or not that is true. Check back with GBA in 100 years from now and the answer will be known ;)
This uncertainty is one reason I like the idea of having the primary air barrier somewhere where it can be repaired. You can schedule a blower door test (or at least a visual inspection) for when the siding is being replaced or repaired, if the air barrier is at the exterior of the wall. You could then apply the latest and greatest product. This is one drawback, in my opinion, to the Larsen truss approach, where the primary air barrier is often deeply sandwiched in the wall.
Roy,
I think that Peter L gave a good answer.
One of the most long-lived air barrier materials is concrete. Concrete can crack, of course, but in general it is very long-lived.
Any air barrier has seams and penetrations, so it is hard to avoid the use of tapes or caulks. Most homes require repairs during their long lives, and if all repairs are made by workers who pay attention to airtightness, there is a good chance that an air barrier will perform well enough to keep the owners satisfied, for many decades -- assuming, of course, that the house starts out well-sealed.