Does Great Stuff shrink?
John Waller| Posted inEnergy Efficiency and Durabilityon
For 1/2″ gaps, should I use Great Stuff or the 2 component foam? Which bonds better, shrinks less?
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Replies
John,
Neither product should shrink if properly installed. Both products are tenacious. However, neither product forms a perfect air seal, and it can sometimes be hard to fill a narrow crack that is only 1/2 inch wide.
Other options (especially if your chief concern is air sealing) include caulk and a high-quality tape, especially one of the European tapes designed for air sealing.
If you have consistent 1/2" gaps, it's easy to use foam backer rod instead of canned foam.