Hi,
We've got a 3' deep/wide cantilevered space on our upper level, with hot water baseboard running on the far end (along the entire wall of that living room space), meaning that the hot water pipes drop down into the cantilevered space at the far end of the cantilever. We are starting some (retrofit) insulation work on the concrete-block walls of the tuck-under garage, which is under the living room that has the cantilever (so, one side-wall of the garage is the point from which the cantilever extends out above), and realize that we should try to address the cantilever, if possible, at this point as well. We opened the ceiling drywall of the garage in two places along the wall with the cantilever, and see that 1) there's no blocking above the foundation/garage wall to air seal/insulate from the cantilever... and 2) the cantilever appears to not be properly air sealed or insulated from down-below -- I can feel metal (soffit?) on the bottom, with cold air coming up in places. There's fiberglass in the cantilever cavities, with facing towards the bottom, but as described, it's not air sealed very well.
My question is how to best address the worst of the cantilever situation, in terms of air-sealing and insulation, without tearing out the soffit from outside (which we're not ready to do at this point), and without creating problems with freeze-ups for those pipes at the far end of the cantilever?
My first thought is to add rigid foam sections (sealed w/caulk) above the garage/foundation wall, to act as block between the cantilever space and the rest of the floor/ceiling space. My concern is that that method could pose more problems for the cantilever pipes (if it would be blocking heat from getting out there - which I know isn't energy-efficient, but possibly has been happening thus far, as the garage is heated space (it's on the downstairs loop, which also runs into the downstairs living space - bad layout, I know). Any suggestions on how to (better) insulate/air seal the cantilever from the side (accessing from the garage ceiling, not from below by removing the soffit covering), taking into consideration the pipes out there? I've been warned by more than one plumber to NOT use spray foam insulation right up to the pipes, as it makes it darn near impossible to get to/work on them, if/when needed... so, in my mind that would rule out spraying in foam that way (am I correct in this assumption?). Can I just leave the cantilever as-is for now (w/ fiberglass in there, but poorly air-sealed) and add the foam blocking, and then later address the actual cantilever space (from below by removing the soffit), or is that a bad idea in terms of the cantilever pipes?
[Forgot to mention earlier, but there hasn't been an issue w/ pipes freezing out there -- once, years ago (previous owner), but no problems in the 3+ years we've owned the home.]
Thanks in advance for your feedback/suggestions -- I'm new to this (but learning)!
Katie
Anchorage, AK (currently in the teens)
NOTE: I added photos showing first the exterior of the cantilever, then photos of the opening in garage ceiling that shows lack of blocking to cantilever, as well as photos back into cavities between ceiling/floor joists that run out into cantilever -- showing existing insulation (which is showing dirt from air flow by the way, but no moisture/mold where I can see it, unless the black is mold and not dirt...?!)
We've got a 3' deep/wide cantilevered space on our upper level, with hot water baseboard running on the far end (along the entire wall of that living room space), meaning that the hot water pipes drop down into the cantilevered space at the far end of the cantilever. We are starting some (retrofit) insulation work on the concrete-block walls of the tuck-under garage, which is under the living room that has the cantilever (so, one side-wall of the garage is the point from which the cantilever extends out above), and realize that we should try to address the cantilever, if possible, at this point as well. We opened the ceiling drywall of the garage in two places along the wall with the cantilever, and see that 1) there's no blocking above the foundation/garage wall to air seal/insulate from the cantilever... and 2) the cantilever appears to not be properly air sealed or insulated from down-below -- I can feel metal (soffit?) on the bottom, with cold air coming up in places. There's fiberglass in the cantilever cavities, with facing towards the bottom, but as described, it's not air sealed very well.
My question is how to best address the worst of the cantilever situation, in terms of air-sealing and insulation, without tearing out the soffit from outside (which we're not ready to do at this point), and without creating problems with freeze-ups for those pipes at the far end of the cantilever?
My first thought is to add rigid foam sections (sealed w/caulk) above the garage/foundation wall, to act as block between the cantilever space and the rest of the floor/ceiling space. My concern is that that method could pose more problems for the cantilever pipes (if it would be blocking heat from getting out there - which I know isn't energy-efficient, but possibly has been happening thus far, as the garage is heated space (it's on the downstairs loop, which also runs into the downstairs living space - bad layout, I know). Any suggestions on how to (better) insulate/air seal the cantilever from the side (accessing from the garage ceiling, not from below by removing the soffit covering), taking into consideration the pipes out there? I've been warned by more than one plumber to NOT use spray foam insulation right up to the pipes, as it makes it darn near impossible to get to/work on them, if/when needed... so, in my mind that would rule out spraying in foam that way (am I correct in this assumption?). Can I just leave the cantilever as-is for now (w/ fiberglass in there, but poorly air-sealed) and add the foam blocking, and then later address the actual cantilever space (from below by removing the soffit), or is that a bad idea in terms of the cantilever pipes?
[Forgot to mention earlier, but there hasn't been an issue w/ pipes freezing out there -- once, years ago (previous owner), but no problems in the 3+ years we've owned the home.]
Thanks in advance for your feedback/suggestions -- I'm new to this (but learning)!
Katie
Anchorage, AK (currently in the teens)
NOTE: I added photos showing first the exterior of the cantilever, then photos of the opening in garage ceiling that shows lack of blocking to cantilever, as well as photos back into cavities between ceiling/floor joists that run out into cantilever -- showing existing insulation (which is showing dirt from air flow by the way, but no moisture/mold where I can see it, unless the black is mold and not dirt...?!)