KEBAK
New Member
Hi there,
First post here - I've been perusing other threads for ideas, but would like to ask a few questions specific to our project.
Background: We're embarking on an insulation project for our heated, currently uninsulated attached garage (1969 home in Anchorage, w/ concrete block foundation/garage walls). This has opened up a new issue, with cantilever space that extends ~ 3' out from one of the garage side walls, in that there is insufficient insulation and air sealing in that cantilever space. We have hot water baseboard heat. The garage is part of the downstairs loop (also runs through living space), and the cantilever contains some piping from the upstairs living room loop (in one of the cavities between floor joists). So, we've got pipe insulation to address both in the garage -- they run along baseboard on the two side walls (one below and one above grade), and then vertically in 3 places up to the ceiling/floor space above -- and also in the cantilever. Obviously we're sensitive to freeze-ups (in Anchorage, AK), so want to find a way to insulate (and air seal, in the cantilever) in a way that won't create freeze-up problems. We have owned the home 3+ years and haven't had recurrent freezing problems (knock on wood) -- only one freeze up along the baseboard in the garage (above grade wall), but that was due to the circulator pump's failure, which of course happened during an extended below-zero cold stretch in town.
I've seen in other posts here that suggest that you want to leave the pipes exposed in the 'warm' direction, and then insulate between the pipes and the cold. In our case, I would interpret that to mean 1) in the cantilever, keeping the space above the pipes free of insulation (towards the LR floor above) and insulating below toward the bottom of the cantilever, and on the side toward the exterior wall... and 2) along the garage walls, insulating behind the pipes between them and the foundation walls and leaving them uninsulated toward the sheetrock/heated garage space.
Now, here are my questions:
- Currently the pipe in the cantilever has gray spongy foam sleeve insulation (maybe 1/2" wall) over it, at least in the stretch of it I can see through the opening of the garage ceiling sheetrock. Then, there is fiberglass insulation under the pipe (toward the cold outside), but also insulation above the pipe, at least as it nears the outside of the cantilever. There's only ~3" of space to insulate under the horizontal stretch of pipe in that cavity, between the pipe and the cantilever bottom (and about 5-6" above the pipe, before reaching the LR subfloor). Also, the cantilever bottom is not air sealed -- there's only metal soffit... I can feel the cold air coming up. There's no blocking either above the foundation/garage wall, to air seal the cantilever from the rest of that ceiling/subfloor space. So, how do I best insulate around these cantilever pipes, to try to avoid freeze-ups? I'd love to be able to not have to pull off the soffit and access that way (it's currently snowing here), but I'm thinking that's what will be needed. If I did remove the soffit, then I'd either have someone come and spray-in foam insulation (it'd be soy-based, w/ R4/in., as it's too cold to do polyurethane now), or, if that's too expensive, then I'm considering a combo of fiberglass batt above w/ rigid foam on the bottom (as a combo thermal and air shield, caulked/foamed just above the metal soffit). In either case, any suggestions on how to 'block off' the pipe there, getting the blocking as close to the pipe as possible in order to maximize space for insulation below/beside it? Would metal flashing be good? Could it be in direct contact w/ the copper pipe? If using polyiso board insulation (R-max Thermasheath), how close can it come to the hot water pipe, w/out being fire hazard? I know that it's not been recommended on these forums to use foam tube insulation in this application, but would that maybe be our only option to keep the pipe out of contact w/ the spray foam/polyiso? The problem is that we don't have a lot of room to insulate between the pipes and cold, so we have to maximize by using the highest R-value product we can that will work in this space. Suggestions? Advice? I wasn't sure how much heat would be traveling DOWN from the LR floor upstairs anyway (heat rises, no?), so wasn't sure if in this situation it would be as important to keep the tube insulation off, and/or the space above the pipe toward the heated space above or not. Feedback?
For the garage walls, which we plan to insulate w/ polyiso foam board (again, R-Max Thermasheath) and then sheetrock over for code, we were going to fit as much foam board behind the pipes as possible w/ space given, then wrap pipes w/ foam tube insulation before sheetrocking (in part to act as barrier between pipe and polyiso board) -- should we skip the tube insulation then, to expose the pipe in the direction of the sheetrock/inside heated garage space?
One more question -- is there an 'industry standard' minimum of insulation that we should have between these pipes and the exterior/cold? This will help inform our choice of products, as well as how far to move the piping out from the walls in the garage.
Sorry for the long post -- just want to describe as much as possible, in hopes it helps clarify what's going on/what we're considering as options.
Any suggestions/advice would be appreciated! Thanks in advance.
First post here - I've been perusing other threads for ideas, but would like to ask a few questions specific to our project.
Background: We're embarking on an insulation project for our heated, currently uninsulated attached garage (1969 home in Anchorage, w/ concrete block foundation/garage walls). This has opened up a new issue, with cantilever space that extends ~ 3' out from one of the garage side walls, in that there is insufficient insulation and air sealing in that cantilever space. We have hot water baseboard heat. The garage is part of the downstairs loop (also runs through living space), and the cantilever contains some piping from the upstairs living room loop (in one of the cavities between floor joists). So, we've got pipe insulation to address both in the garage -- they run along baseboard on the two side walls (one below and one above grade), and then vertically in 3 places up to the ceiling/floor space above -- and also in the cantilever. Obviously we're sensitive to freeze-ups (in Anchorage, AK), so want to find a way to insulate (and air seal, in the cantilever) in a way that won't create freeze-up problems. We have owned the home 3+ years and haven't had recurrent freezing problems (knock on wood) -- only one freeze up along the baseboard in the garage (above grade wall), but that was due to the circulator pump's failure, which of course happened during an extended below-zero cold stretch in town.
I've seen in other posts here that suggest that you want to leave the pipes exposed in the 'warm' direction, and then insulate between the pipes and the cold. In our case, I would interpret that to mean 1) in the cantilever, keeping the space above the pipes free of insulation (towards the LR floor above) and insulating below toward the bottom of the cantilever, and on the side toward the exterior wall... and 2) along the garage walls, insulating behind the pipes between them and the foundation walls and leaving them uninsulated toward the sheetrock/heated garage space.
Now, here are my questions:
- Currently the pipe in the cantilever has gray spongy foam sleeve insulation (maybe 1/2" wall) over it, at least in the stretch of it I can see through the opening of the garage ceiling sheetrock. Then, there is fiberglass insulation under the pipe (toward the cold outside), but also insulation above the pipe, at least as it nears the outside of the cantilever. There's only ~3" of space to insulate under the horizontal stretch of pipe in that cavity, between the pipe and the cantilever bottom (and about 5-6" above the pipe, before reaching the LR subfloor). Also, the cantilever bottom is not air sealed -- there's only metal soffit... I can feel the cold air coming up. There's no blocking either above the foundation/garage wall, to air seal the cantilever from the rest of that ceiling/subfloor space. So, how do I best insulate around these cantilever pipes, to try to avoid freeze-ups? I'd love to be able to not have to pull off the soffit and access that way (it's currently snowing here), but I'm thinking that's what will be needed. If I did remove the soffit, then I'd either have someone come and spray-in foam insulation (it'd be soy-based, w/ R4/in., as it's too cold to do polyurethane now), or, if that's too expensive, then I'm considering a combo of fiberglass batt above w/ rigid foam on the bottom (as a combo thermal and air shield, caulked/foamed just above the metal soffit). In either case, any suggestions on how to 'block off' the pipe there, getting the blocking as close to the pipe as possible in order to maximize space for insulation below/beside it? Would metal flashing be good? Could it be in direct contact w/ the copper pipe? If using polyiso board insulation (R-max Thermasheath), how close can it come to the hot water pipe, w/out being fire hazard? I know that it's not been recommended on these forums to use foam tube insulation in this application, but would that maybe be our only option to keep the pipe out of contact w/ the spray foam/polyiso? The problem is that we don't have a lot of room to insulate between the pipes and cold, so we have to maximize by using the highest R-value product we can that will work in this space. Suggestions? Advice? I wasn't sure how much heat would be traveling DOWN from the LR floor upstairs anyway (heat rises, no?), so wasn't sure if in this situation it would be as important to keep the tube insulation off, and/or the space above the pipe toward the heated space above or not. Feedback?
For the garage walls, which we plan to insulate w/ polyiso foam board (again, R-Max Thermasheath) and then sheetrock over for code, we were going to fit as much foam board behind the pipes as possible w/ space given, then wrap pipes w/ foam tube insulation before sheetrocking (in part to act as barrier between pipe and polyiso board) -- should we skip the tube insulation then, to expose the pipe in the direction of the sheetrock/inside heated garage space?
One more question -- is there an 'industry standard' minimum of insulation that we should have between these pipes and the exterior/cold? This will help inform our choice of products, as well as how far to move the piping out from the walls in the garage.
Sorry for the long post -- just want to describe as much as possible, in hopes it helps clarify what's going on/what we're considering as options.
Any suggestions/advice would be appreciated! Thanks in advance.
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