Craig Summers
01-21-2009, 4:16 PM
We bought an existing house and I have been slowly upgrading various portions of it. The current project is an insulation upgrade: ductwork and crawlspace
I created goals for my project
1) Improve the living conditions of first floor
2) Reduce winter/summer energy costs
3) Add utility lighting to crawlspace and attic
Existing conditions:
> Ventilated dirt crawlspace with heavy (?mil) plastic sheeting on ground. Max clearance of 3’ from dirt to joist. Joists are 2x10. There are 2 areas, 25x30 and 12x24.
> Exposed metal ducts with partial sealing with old cloth ‘Duck tape’, main trunk/branches in crawlspace, return through attic. Trunk is: 24’ of 8x24 and 25’ of 8x18, hangs 2” from joists. Branches are mostly 6” pipe, either 5’ or 20’ long that connect to 3¼x14 wall chase duct, mostly running up inside the parallel joist spacing. Attic return duct is 8x24 - 14’ and 8x14 – 7’.
> Water pipes ¾“ dia copper, cold water with foam wrap, hot water with thin fiberglass wrap.
> Crawlspace existing insulation is R-11 stapled to the ceiling (floor), minus the fiberglass. Might be R-0.5 left in place?
> One branch duct is sealed off (dud) with its wall chase duct blocked off, and another branch duct goes to what I think is a dead end, as I cannot locate what register it should go to upstairs (either an interior wall or closet floor).
> The first floor is all wood floors, so they stay cold in the winter.
Basic plan:
a) Add 7 switched lights to crawlspace, and 2 switched lights to attic. (convenience for future)
b) Seal all ductwork with foil tape
c) Add 3” R-8 Fiberglass Insulation Duct Wrap (it’s also the new code)
d) Seal all electrical/plumbing/duct penetrations
e) Add R-30 Kraft insulation batts to crawlspace ceiling, its $0.51/sq ft here at the Borg (cheaper than local distributors). Kraft facing to be installed against the floor.
f) Possible heat tape for plumbing pipes
I did read the spec and instructions from CertainTeed for their duct wrap. I know to add more inches to the length of insulation when cutting. (For 3” wrap its +11.5 for rectangular and +17 for round) Then trim the fiberglass back 2” for foil overlap.
I have already started the project, and have bought the foil duct sealing tape, the duct wrap, and the reinforced duct wrap tape via McCormicks (http://www.mccormickinsulation.com/). They were very helpful for a homeowner, just make sure you specify that you are looking for 3” R-8 Duct Wrap, they might have it in stock. My local store got confused and heard homeowner, and said ‘not in stock’. One of their sister stores in Hagerstown MD (3 hour round trip) had it in stock, and showed me that the local one did have it in stock there. I got a discount for my time/trouble. Normally expect to pay @ $ 104 per 4’x50’ roll of R-8.
I have put in the 7 lights for the crawlspace. I have removed all existing duck tape at the trunk and return, and replaced with foil tape. I have sealed all seams in the trunk line.
I have found that using cheap Window cleaner is helpful when cleaning the duct surfaces, the wetness makes it easier to clean the dust, it mitigates airborne dust, and dries quickly. I have had to remove some acorn shells from the top of the duct, so don’t be surprised to find stuff on your ducts.
Now for some specific questions:
Has anyone tackled this before? Any pointers?
Now I am starting to insulate the trunk line. Has anyone ever cut insulation to fit a 6” Top Take-off boot? Is there a template out there? I know that a simple 6” dia duct needs insulation @ 36” rough length (6*Pi+17 to be exact) less the 2” overlap cutback. So a piece for these connections is similar.
http://ec1-images.acehardwareoutlet.com/70/products/pix/261018.jpg
I have 12 or so of these to do, and limited space to do it. If there is no template, I am planning on removing the one dud takeoff and use that as a template. And the same question for the transition 6” round to 3¼x14, otherwise for that I might buy and return a ‘sample’ from the Borgs.
When the duct first comes from furnace into the crawlspace, it goes through a block wall. When I put insulation on the duct, what should I do with the ‘open end’ of the insulation? Should it be left alone, taped to the duct, or stapled to new blocking?
One of my fears/questions is whether I need to add heater tape to the plumbing pipes after I insulate. I don’t know if the loss of ambient heating would necessitate removing the existing pipe insulation, adding tape, and re-insulating. I know it won’t hurt, just more time.
I see something written about using staples to connect duct wrap. Should I use that (in addition to reinforced tape) and if so, what kind of stapler is it? I assume it is something special, if it can staple from one side with nothing to drive the staples into.
I created goals for my project
1) Improve the living conditions of first floor
2) Reduce winter/summer energy costs
3) Add utility lighting to crawlspace and attic
Existing conditions:
> Ventilated dirt crawlspace with heavy (?mil) plastic sheeting on ground. Max clearance of 3’ from dirt to joist. Joists are 2x10. There are 2 areas, 25x30 and 12x24.
> Exposed metal ducts with partial sealing with old cloth ‘Duck tape’, main trunk/branches in crawlspace, return through attic. Trunk is: 24’ of 8x24 and 25’ of 8x18, hangs 2” from joists. Branches are mostly 6” pipe, either 5’ or 20’ long that connect to 3¼x14 wall chase duct, mostly running up inside the parallel joist spacing. Attic return duct is 8x24 - 14’ and 8x14 – 7’.
> Water pipes ¾“ dia copper, cold water with foam wrap, hot water with thin fiberglass wrap.
> Crawlspace existing insulation is R-11 stapled to the ceiling (floor), minus the fiberglass. Might be R-0.5 left in place?
> One branch duct is sealed off (dud) with its wall chase duct blocked off, and another branch duct goes to what I think is a dead end, as I cannot locate what register it should go to upstairs (either an interior wall or closet floor).
> The first floor is all wood floors, so they stay cold in the winter.
Basic plan:
a) Add 7 switched lights to crawlspace, and 2 switched lights to attic. (convenience for future)
b) Seal all ductwork with foil tape
c) Add 3” R-8 Fiberglass Insulation Duct Wrap (it’s also the new code)
d) Seal all electrical/plumbing/duct penetrations
e) Add R-30 Kraft insulation batts to crawlspace ceiling, its $0.51/sq ft here at the Borg (cheaper than local distributors). Kraft facing to be installed against the floor.
f) Possible heat tape for plumbing pipes
I did read the spec and instructions from CertainTeed for their duct wrap. I know to add more inches to the length of insulation when cutting. (For 3” wrap its +11.5 for rectangular and +17 for round) Then trim the fiberglass back 2” for foil overlap.
I have already started the project, and have bought the foil duct sealing tape, the duct wrap, and the reinforced duct wrap tape via McCormicks (http://www.mccormickinsulation.com/). They were very helpful for a homeowner, just make sure you specify that you are looking for 3” R-8 Duct Wrap, they might have it in stock. My local store got confused and heard homeowner, and said ‘not in stock’. One of their sister stores in Hagerstown MD (3 hour round trip) had it in stock, and showed me that the local one did have it in stock there. I got a discount for my time/trouble. Normally expect to pay @ $ 104 per 4’x50’ roll of R-8.
I have put in the 7 lights for the crawlspace. I have removed all existing duck tape at the trunk and return, and replaced with foil tape. I have sealed all seams in the trunk line.
I have found that using cheap Window cleaner is helpful when cleaning the duct surfaces, the wetness makes it easier to clean the dust, it mitigates airborne dust, and dries quickly. I have had to remove some acorn shells from the top of the duct, so don’t be surprised to find stuff on your ducts.
Now for some specific questions:
Has anyone tackled this before? Any pointers?
Now I am starting to insulate the trunk line. Has anyone ever cut insulation to fit a 6” Top Take-off boot? Is there a template out there? I know that a simple 6” dia duct needs insulation @ 36” rough length (6*Pi+17 to be exact) less the 2” overlap cutback. So a piece for these connections is similar.
http://ec1-images.acehardwareoutlet.com/70/products/pix/261018.jpg
I have 12 or so of these to do, and limited space to do it. If there is no template, I am planning on removing the one dud takeoff and use that as a template. And the same question for the transition 6” round to 3¼x14, otherwise for that I might buy and return a ‘sample’ from the Borgs.
When the duct first comes from furnace into the crawlspace, it goes through a block wall. When I put insulation on the duct, what should I do with the ‘open end’ of the insulation? Should it be left alone, taped to the duct, or stapled to new blocking?
One of my fears/questions is whether I need to add heater tape to the plumbing pipes after I insulate. I don’t know if the loss of ambient heating would necessitate removing the existing pipe insulation, adding tape, and re-insulating. I know it won’t hurt, just more time.
I see something written about using staples to connect duct wrap. Should I use that (in addition to reinforced tape) and if so, what kind of stapler is it? I assume it is something special, if it can staple from one side with nothing to drive the staples into.