Let's Talk Insulation!!

[thephotohound]

OK... I'll start. I have a 1970's contemporary with R-13 in the walls and R-19 in the ceilings. It is two stories, with the "lower level" doubling as the basement. The lower level is on a slab, with concrete kneewalls (shredded fiberglass between the concrete and studs). That floor is 50% above grade, and the other half is 50% below grade (sloped yard). There are windows in every room - lots of natural light. There is no insulation in the lower level ceiling, as it has always been 100% finished. The upper level is comprised of a 500 sq ft Great Room with 12 foot ceilings and recessed lights (a.k.a. little chimneys). We live in Central MA, 900 ft above sea level, with no trees to the west, and minimal trees to the north. The windows are original double pane, wood frame casements. Oh, I forgot to mention... 2 ft cantilevers on either side of the upper level.

What we have done so far to combat the air leakage is silicone every crack on the exterior and use minimal expanding latex foam in every nook and cranny. Next, I have begun the arduous task of removing the molding around windows and doors, and adding the same spray foam. I have caulked/spray foamed around every recessed light (they're all non-IC and embedded in the slope of the cathedral ceiling, so I can't even get to them). I just bought R-19 unfaced batts to run perpendicular to the joists above the cathedral ceiling (adding any more would restrict airflow to the louver vents in my attic). I've decided not to remove the walls in the basement, but if I ever have to, I'll glue ploystyrene to the concrete and remove the shredded fiberglass. When we reside (existing is ugly, inefficient board and batten), we'll add 2 inches of polystyrene (R-10) to make the walls R-23. Still not enough, but much better.

Any other ideas? Share your set-ups!

 

[eba1225]

Hound,

I have a 2 story colonial, 1964 construction, 8ft ceilings. The basement is completely underground with a walkout stairway that goes up to ground level.

I did the same thing with my attic laying R-30 across the joist to make it R-49.
With regard to my walls I am concerned that I do not have enough, but am not in the position to check or replace.
As I have repainted rooms I made it a point to caulk whereever there was a opening, next to window or door trim.
Had the house resided a couple of years ago but did not have additional insulation added, am kicking myself now.
The finished basement maintains a temp of 60-75 all year long, winter it is warmer, summer it is cooler.
I do have insulation in the basement where the walls meet the floor joist, basically insulates the ledgerboards as they were cold in previous years.
Had the windows replaced 10 yrs ago with double pane, vinyl. They are ok but by no means the top of the line, are much better than the single pane that we used to have.

Erik

 

[Mike Wilson]

Photo, who makes the high hats in your cathedral ceiling? If it's Cooper (Halo), then have I got a solution for you...

-- Mike

 

[tutu_sue]

For outlets and switches on the outer walls, install the foam gaskets. I used latex foam between the boxes and sheetrock first. Good idea to turn off breakers first, so you don't curl your hair. Also, you can caulk outside where the foundation meets the sill/sheathing/siding. Also seal outside lighting fixture boxes, faucets, pipes, dryer vent, fans, etc.

 

[thephotohound]

Mike - I don't know who makes them... will have to check. I know the model starts with A157... Are you talking about the airtight covers? Been thinking about it...

EBA - the basement doesn;t get colder than 60? That's awesome. I am in the process of installing a pellet stove in the basement right now to warm it up (it will eventually be an 18x24 family room, den, and dark room.)

 

[Mike Wilson]

Mike - I don't know who makes them... will have to check. I know the model starts with A157... Are you talking about the airtight covers? Been thinking about it...

EBA - the basement doesn;t get colder than 60? That's awesome. I am in the process of installing a pellet stove in the basement right now to warm it up (it will eventually be an 18x24 family room, den, and dark room.)

Yes, airtight covers. I have 36 high hats in this house, all made by Cooper Electric (Halo), and none of them were air tight. I started a replacement program for the eyeballs, and have done 24 of them so far. Hoping to complete the last 12 this year. It has cut down the air infiltration (exfiltration?) immensely. They say that 4 cubic feet of air per minute can be lost through them... think about it, 4 per minute, times 36, times 60, times 24... that's a lot of heat loss.

TuTu_Sue - On the topic of caulking around the undersides of the house, where the foundation meets the sill... are you talking about physically where the poured concrete meets the sill boards (which sit on some insulation here, looks like a thin strip of compressed fiberglass)? How did you insulate it, and did you do it on the inside, or the outside? Also, what about the termite shield, that strip of metal that runs around the bottom of the house to repel termites... is caulking over that making it ineffective?

-- Mike

 

[thephotohound]

Thanks, Mike. You're right - that is a lot of heat loss. A TREMENDOUS amount! Where did you find them (airtight covers)? I found one site, but they require a minimum order of $100.

 

[tutu_sue]

Yes caulking where the concrete meets the sill. My basement isn't finished so I was able to do it from inside. I also have fiberglass under the PT still, but there were spots where I didn't see any. A run of caulk will take care of air AND humidity getting in there. Don't know about your termite shield - I don't have that. I've also read where it's best to also good to caulk the rim joist 'box' before putting fiberglass in there to prevent condensation from cold air getting in under the sheathing.

 

[eba1225]

Hound,

Yes never colder than 60. It is amazing the narrow band of temperature that it stays. It is fully underground (6.5 ft) and the oil furnace is down there. The "Boss" and I really like it because in the summer we go down there for some instant A/C w/o using the A/C.

Erik

 

[Mike Wilson]

Thanks, Mike. You're right - that is a lot of heat loss. A TREMENDOUS amount! Where did you find them (airtight covers)? I found one site, but they require a minimum order of $100.

First I had to search online to find that they actually made them. I was initially looking to replace the actual cans, but because all my ceilings are cathedral, I can't remove them without significant sheetrocking. I found that Halo has an air tight eyeball they sell that replaces the exiting eyeball. So, while the can is not airtight, no air gets past the bulb or the open ring around the eye. I had to special order them from my local electrical supply house, took 6 weeks to get them in, and they cost about 26 bucks each. Either way, I can already tell the difference when the wind blows. My house is 248' back from the bluff on the water, up about 120' vertically, so I get massive amounts of wind here in the winter.

-- Mike

 

[Mike Wilson]

Yes caulking where the concrete meets the sill. My basement isn't finished so I was able to do it from inside. I also have fiberglass under the PT still, but there were spots where I didn't see any. A run of caulk will take care of air AND humidity getting in there. Don't know about your termite shield - I don't have that. I've also read where it's best to also good to caulk the rim joist 'box' before putting fiberglass in there to prevent condensation from cold air getting in under the sheathing.

My basement is unfinished, so I can do this as well. What type of caulk did you use, regular paintable caulk, clear window and door, or expanding foam stuff? Also, if I am doing this from the inside, it does not appear that it will interfere with the termite strip, that's on the outside.

-- Mike

 

[thephotohound]

Just in the few cooler nights we had already (mid 30's), I can already tell how much effect the exterior sealing has had. I took a case of silicone and 6 cans of expanding latex, and went like a mad man on the exterior (35 year old board & batten). The air infiltration was minimal, and will be non-existent once I install new weatherstripping on both sliders and caulk between the drywall and floor.

 

[tutu_sue]

Had a couple tubes of Alex Plus caulk tubes laying around so I used that.

 

[Mike Wilson]

Just in the few cooler nights we had already (mid 30's), I can already tell how much effect the exterior sealing has had. I took a case of silicone and 6 cans of expanding latex, and went like a mad man on the exterior (35 year old board & batten). The air infiltration was minimal, and will be non-existent once I install new weatherstripping on both sliders and caulk between the drywall and floor.

Did you seal up the bottoms of the boards on the exterior as well? If so, what did you use?


-- Mike

 

[Mike Wilson]

Had a couple tubes of Alex Plus caulk tubes laying around so I used that.

Great, so DAP it is... I have a case of it in the basement. I assume you just went right over the sill joint and wiped it in, right?

-- Mike

 

[thephotohound]

Alex Plus is the best, and coincidentally the cheapest too! It's got the paintability of latex with the flexibility of silicone. I wouldn't use it outside, though. The latex tends to shrink in extreme temps. I wish I had access to my sill joints... I would do the same.

Mike - I was going to seal where the siding/plywood meets the foundation, but figured it was too much $$ for too little return. My biggest concern has been wind infiltration. Expanding foam can get expensive... Plus, I'm not sure what the implications are with trapping moisture in between the siding and the plywood...

 

[tutu_sue]

Yep, but I used the DAP red cap tool thingy to wipe it in so I wouldn't get it on my fingers. If I ever decide to do the outside, I plan on using the clear silicone 50 year stuff. Not sure about what brand/kind until I go to the store.

 

[thephotohound]

Great idea. I usually use incense, but I love the bubbles!

 

[tutu_sue]

Yes, I'm aware of that. I'm going to caulk foundation under siding, so it's not an issue, but thank you for looking out for me Leave some bubbles for the kids.

 

[WILDSOURDOUGH]

Fine Homebuliding has a great article this month (October/november) on insulation and heat wasters.
"If you insulate your ceiling to r38 and you miss just 0.5% (one half of one percent) your insulation factor drops to r28 !" (This was a timely article for us, as we were installing strapping and insulation for the ceiling of our new home- wife and I were up there many days and nights installing and stuffing insulation in every crack and crevice-except the soffits". Used IC cans- think you might get away with covers that you use for damp locations-bathrooms, cuz they have a built in gasket.
Article also says that those 'catileaver areas' you have can be a big problem- might want to double check them.

 

[thephotohound]

Wild - Thanks for the help. Good info... the cantilevers have been a source of great debate. I went around and sealed every square inch of them, and there is R-19 existing in them right now. When I re-side, I'll put 2 inches of polystyrene, making it R-29. That should do it!

 

[Nofossil]

Getting leaks is good. If you want to be a fanatic, there are four other areas that might help:

1) The band joists. There is often NO insulation there, and they're strategically located right above the ceiling on each floor, where the heat has risen to. May not be able to get at them, but if you can it would help.

2) The outside of the concrete foundation.

3) If you burn wood, can you bring in a dedicated outdoor air supply duct? If not, it's drawing a vacuum inside the house that WILL draw in outside air unless you put a ZipLoc bag around your house. Then it will just suffocate you.

4) Last, and almost always the biggest - radiant / conductive heat loss through the window glass. Mylar blinds eliminate radiant loss. Insulated blinds reduce conductive loss. Internal or external shutters do a good job as well. For fun, tack up a piece of foil-faced insulating board over each window in one room. You will be amazed at the difference. Not practical as a solution, but it's a real eye-opener to see what you lose through the glass.

 

[thephotohound]

Fossil -

Love the tips... I am an admitted fanatic.

1. Can't get at the band joists, but good idea
2. When you say the outside of the foundation, do you suggest polystyrene with adhesive, then a skimcoat of mortar like Rhonemas is doing?
3. What do you mean by "bringing in a dedicated outside air supply" for the wood stove? Doesn't the chimney already do that? I have a pellet stove that I'm hooking up in the lower level and I was considering a fresh air intake on that. Would you recommend it?
4. We are currently replacing our 32 year old double pane Anderson casements one by one with Low E, Argon filled Energy Star windows. I'm sure we'll see a big difference. We may consider the Mylar blinds, but as you know, that one isn;t up to me. It's not my jurisdiction, so to speak.

I am so excited to see the difference with the added insulation and air leak issues minimized. My next goal is to find the gaskets that go around the recessed lights I have (6 inch). I can't find just the gaskets anywhere! Any ideas?

 

[Nofossil]

Fossil -

Love the tips... I am an admitted fanatic.

1. Can't get at the band joists, but good idea
2. When you say the outside of the foundation, do you suggest polystyrene with adhesive, then a skimcoat of mortar like Rhonemas is doing?
3. What do you mean by "bringing in a dedicated outside air supply" for the wood stove? Doesn't the chimney already do that? I have a pellet stove that I'm hooking up in the lower level and I was considering a fresh air intake on that. Would you recommend it?
4. We are currently replacing our 32 year old double pane Anderson casements one by one with Low E, Argon filled Energy Star windows. I'm sure we'll see a big difference. We may consider the Mylar blinds, but as you know, that one isn;t up to me. It's not my jurisdiction, so to speak.

I am so excited to see the difference with the added insulation and air leak issues minimized. My next goal is to find the gaskets that go around the recessed lights I have (6 inch). I can't find just the gaskets anywhere! Any ideas?

For foundation insulation, the 2" polystyrene is the most common approach (that's what I have). There may be better ideas.

By 'dedicated outside air supply' I mean for the air intake of the stove. Woodstoves require a lot of air for the combustion process. Nowhere near as much as a fireplace, but they need more than most folks realize. This is easy to do on some models, near impossible on others. A 4" duct from outside with a sliding gate valve is good. Woodworking supply places carry the right kind of stuff, intended for dust collection systems. It needs to transition to metal near the stove, but can be plastic elsewhere. Hard to do for a stove in a living space, but important for a basement boiler / furnace.

Also consider and air-to-air heat exchanger for the house. Vast improvement in indoor air quality.

If you can get at the recessed lights from above, you can glue a can / box to the top surface of the ceiling and foam where they wires go through - good for top floor lights if there's an unheated attic above. Make sure that your lights are rated for being insulated in that way - some depend on convection to cool them. I think they make lights for ceilings with blown-in insulation on top of them - that should be safe.