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We are getting ready to insulate our home and are considering tripolymer foam or cellulose. I have insulated two homes myself w/ cellulose and have no complaints about this material – no settling in walls opened 10 yrs later – but we did see some bridging and voids. Often this was caused by wiring or partial blocking.
Our new home (built in 1954) has a four layer aluminum foil over paper insulation in its exterior walls. I think that we will get excessive bridging with cellulose and only a partial fill.
The tripolymer people say they will poke the hose through the insulation (very easy to do, it does not have much strength) until it slides down the inside wall, then fill up the cavity, pulling the hose out as it fills.
I have two questions. 1. Will the existing foil which is stapled to the studs cause the foam to fill up a tapered cavity? I expect the paper/foil insulation will belly out as the foam fills the space, but it will hold tight where it is stapled to the studs. This will give me a piece of foam thickest in the center (of the stud space) that tapers to zero next to the studs – where the foil was stapled.
2. What is the final r-value of a tripolymer insulated cavity (with standard 3 1/2″ studs 16″ o.c.)? They advertise .5 to 1.5% shrinkage but they quote an r value based on solid plank foam (i.e. w/ no air gap due to shrinking insulaton).
Replies
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We are getting ready to insulate our home and are considering tripolymer foam or cellulose. I have insulated two homes myself w/ cellulose and have no complaints about this material - no settling in walls opened 10 yrs later - but we did see some bridging and voids. Often this was caused by wiring or partial blocking.
Our new home (built in 1954) has a four layer aluminum foil over paper insulation in its exterior walls. I think that we will get excessive bridging with cellulose and only a partial fill.
The tripolymer people say they will poke the hose through the insulation (very easy to do, it does not have much strength) until it slides down the inside wall, then fill up the cavity, pulling the hose out as it fills.
I have two questions. 1. Will the existing foil which is stapled to the studs cause the foam to fill up a tapered cavity? I expect the paper/foil insulation will belly out as the foam fills the space, but it will hold tight where it is stapled to the studs. This will give me a piece of foam thickest in the center (of the stud space) that tapers to zero next to the studs - where the foil was stapled.
2. What is the final r-value of a tripolymer insulated cavity (with standard 3 1/2" studs 16" o.c.)? They advertise .5 to 1.5% shrinkage but they quote an r value based on solid plank foam (i.e. w/ no air gap due to shrinking insulaton).