Air sealing success stories

[EatenByLimestone]

Last year we had a bunch of stories about air sealing our houses. It's time to fess up and tell if they were successful or not.

I'll start. Last year I finished off my attic and felt really good about the job I did insulating and such. Then the snow came and I got to see all of the patches of melted snow. The largest one was over a spot that I blew 18" of cellulose over. That was the event that started my airsealing education and campaign. I went around with a caulk gun and then started putting up foam boards and then sealing around them. By the end of winter I had most of it done. I still have one area of kneewall to do, but I want to see how bad the snow melts above it to serve as motivation. Other than that spot I believe I'm sealed down to the floorboards upstairs.

Downstairs I already had new windows put in. I finished with the new windows in 2009. Last winter I ran around on a windy day and sealed around the outlets. This summer I finished a closet that I lost the plaster in due to a leak on one wall and then condensation on another after the warm air was able to get into the wall. It's all insulated and sealed now. I'd like to put new storm doors on the front and back door, but they are expensive so I don't see it happening before next summer.

I started working in the basement by replacing 4 single pane windows that were cracked and didn't open with 3 hoppers and one sliding window. I'll be hitting the rim joists this winter.

So results:

The house stays much warmer. Yesterday, after a smoke issue due to a yellow jacket nest in the was cleared, I got the woodstove in the unfinished basement running. I burnt about a load and a half with the last fill around 5pm. My house is still 69F off of a high of 70F when I went to bed after the temp dropping to the 39F last night. It's been as high as 53 today and is windy with rain today. We're supposed to get down to 34F tonight, so I may start another load if the temp starts to fall inside.

Right now I'm happy as a clam with the air sealing I've done.

Matt

 

[velvetfoot]

On a side note, perhaps that downdraft was a symptom of a tighter house!

 

[EatenByLimestone]

Maybe. If I continue to have a lighting issue I'll have to fix that one kneewall to stop the house from acting like a chimney. It should be clear in a few days if that is the case. I'll be doing a bunch of paper charges if it is.

 

[velvetfoot]

In a little while, the stove will always be warm and there won't be an issue.

 

[EatenByLimestone]

That will be nice...

 

[Where2]

I'm very impressed. If I read your post correctly, the last load into the wood stove was around 5PM, and at noon the following day you had dropped one degree with anywhere from a 30°F to 16°F temperature differential between inside and outside, including wind and rain.

If you only understood how inefficient houses in Florida are, you would cry. Florida houses cannot keep a 10°F temperature differential for an afternoon.

 

[EatenByLimestone]

I lived in W. Palm Beach from '86 to '94. I really wasn't into houses as a teenager, but I think we had electric heat. I know that we didn't have natural gas to the house as we had a small propane tank burried in the back yard, but that only heated a hot tub that my parents installed. I know the house was made of block with a stucco exterior. I have no idea if and how well it was insulated though. I know my father didn't turn on the AC enough and I had mold growing in the corners of my room. It's odd, I can't imagine not knowing the source of heat in a house. The house we lived in before that (back in NY) had oil heat and a woodstove in the family room. I guess it's a matter of necessity up here, but didn't seem important down there.

I ended up lighting the stove about 45 minutes ago and the house was at 67F. Outside was at 45F and there were a few coals in the ashes when I stirred them. Not enough to do anymore than keep the firebox warm. I figure I'll do a PR coup with the wife and keep her warm.

Matt

 

[begreen]

We sealed up so many leaks in the 2006 remodel that it is like a whole new house for heating. Sealing the rim joist and then insulating it along with the crawlspace walls made a huge difference in floor temps in the winter. The crawlspace never goes below 60F now. However, there is still too much glass area for this size house, but that is not going to change. Maybe we will get around to insulated curtains some day.

 

[B-Mod]

I built my own interior storm windows, using glass, and magnets to hold the glass in place. Works pretty slick. I also put Styrofoam in all windows, some totally covered, others about 2/3 covered if I wanted to see out, or get more sunlight in. This fall I will be building interior storm window in the basement single pane windows, and maybe getting to the rim joists.....

 

[EatenByLimestone]

Do you have any pics of the storm windows? They sound pretty nice!

Matt

 

[B-Mod]

They are very simple, my windows have a built in piece of wood about 1" from the glass of the window, it is about 3/4" of an inch wide. I bought rolls of strip magnets, you have to look for the ones that work to they attract each other, and have an adhesive backing on them. I attached one to the wood, then found it best to put the other attracted to the installed magnet. Then removed the protectors from the magnets adhesive, and then inserted the glass in the opening. If you stick the magnets on both the window frame, and the glass, they do not line up exact, and will actually repel each other if they are enough out of alignment. I install a few thumbtacks as a back up to the magnets, just in case, lol. I used glass as it was quite a bit cheaper than plexiglass.....

 

[kod198707]

Instead of styrofoam, I read that bubble wrap works well. It will also let in light, and rolls up for storage.

 

[EJL923]

I've been contemplating sealing/ins rim joists, been wondering what the payback on that job is?

 

[ailanthus]

I just posted this under another thread seconds ago, but it would be appropriate for here as well - here's my story from ~3 years ago:

I had a blower door test done for $300, then spent another ~$800-1000 on DIY projects (attic insulation, duct sealing/insulation, etc. etc.) and then switched to wood heat - so I have no idea how effective it all was. The purpose of doing it all was that I didn't think we could comfortably heat the whole house with wood without some improvements. We had been paying ~$2000 annually on heating oil, but now we're using wood heat 99% of the time.. I had to install a new chimney and stove, so some money was definitely spent, but the payback will be relatively short.

 

[EatenByLimestone]

Well, it's been colder now and I have some updates. The house has been warmer this year and the humidifier has to be refilled much less. I'm counting that as a success story for my upstairs air sealing.

I decided to start on the rim joist and sill plate. Well, that's going to require more foam than I thought. I think a drunk guy did the block work and parge coat. There are plenty of shims under the sill plate and then the bays in the blocks are open so I'm stuffing Roxul into the open bays (Roxul as opposed to something else because I have about 3/4 of a bag of it and don't know what else to do with it.) and foaming over the openings. I'm also foaming around foam boards placed between the floor joists, right up against the rim joist. I'm placing the foil side toward the inside.

 

[woodgeek]

Matt,

How much of the block walls are above grade? Are they already insulated on the inside? Depending, you might want to think about filling the block cavities with something pourable like perlite. The open cavities will have huge horizontal and vertical heat transport by convection.

You would want to get the perlite that is treated to be hydrophobic, for masonry app, not the garden stuff (that could absorb water). Its available over the 'net, but the shipping is $$. If you found a drivable source, it could be quite affordable and effective....

 

[woodgeek]

Yar, and my airsealing story is a 1960 house, with ACH_50 estimated to be 15-20 when I bought, dropping to 6-7 (measured) after extensive DIY work in the attic and windows. This was dropped further to 4-5 (about the limit w/o forced ventilation) by some pros for about $1500 after an energy audit.

 

[EatenByLimestone]

I think I'll insulate outside the block some time in the future. It's just the time/money thing. When you have 1, the other isn't there. I couldn't believe the gaps I filled though. There were 1/2" and 3/4" shims all over the place. I got the back wall done last night. I'll work my way around the house in the next few days.

Matt

 

[woodgeek]

Understood. I would go for the perlite cuz w/o the exterior finish details, its a lot easier and cheaper than exterior foam (but also less effective). You could just skip foaming the top of the cavity to keep the option open for later....

 

[laynes69]

I airsealed our attic a couple years ago, which dropped our heating demand by probably 30%, we had over 30 open cavies from interior walls dumping heated air into the attic. We saw a huge improvement, but we still had 2 major areas of our home that were extremely drafty. Our laundry room was half rotten, and whenever I would walk in the room, the floor could just about freeze water. It was an old part of the house that's was built after the initial construction, but well over a hundred years old. Our den was the other problem area. Extremely drafty, and very cold.

Well this summer I gutted the den, and tore off the old laundry room from the house. In place of the laundry room, we built a 2 story addition. The den was airsealed, and insulated (no drywall yet). Well I'll just say it's a huge improvement, even after adding square footage to the home. Currently, it's 16 degrees and falling (looking to be around 11 tonight). Before, It was a chore to try and not have a large coalbed build up. The house would be warm, but we would be goin thru a bit of wood. After all the improvements, we are able to let the coals burn down. The house is staying much warmer, and we are burning less wood. Last night I loaded the furnace at 10pm, and set the thermostat for 72. When I woke up at 7:30am, the house was 69 and we had a nice coal bed. Within a half hour, the house was back at 72.

I still need to concentrate on the basement, where there's alot of room for improvement. Menards carries a diy foaming kit, which I want to use on our sills. We have half concrete block and half boulder foundation walls with large beams on top. It's a problem area that will be difficult to fix. People at work think I'm crazy, but I enjoy comfort, and savings.

 

[B-Mod]

I just bought some the diy foaming kits from Menards, but I am not sure when I will get to using it yet. Hope they work good.

 

[wingsfan]

I just bought some the diy foaming kits from Menards, but I am not sure when I will get to using it yet. Hope they work good.

let us know how that works, i'd like to maybee try that.

 

[1750]

My preference would be to create a thermal break from the grade/subgrade exterior temps by insulating the exterior basement walls, but barring that, does it make sense to use foam panels to insulate the interior? Once the cold has communicated through the wall from the outside into the building envelope, isn't the point moot?

 

[woodgeek]

Basement insulation is a v complex topic for a new design. You can insulate the interior of a basement wall with a water/mold resistant foam, but then you would also want to put a thermal break between the slab and the wall, lest the cold wall sink heat from the slab (which should have R-10+ insulation under it).

In retrofit situations, its a free for all...anything built before 1990 or so is such an uninsulated horror show, that anything you do should improve the performance is a good idea...just avoid potential wetting/wicking/mold issues.

I have a lot of foundation wall that is 50% above grade, that is fully finished in the interior with drywall on 1" furring strips...a 1" uninsulated cavity. Kind of a stumper from a retrofit point of view (w/o serious demo)....I might talk to an icynene guy about the above grade parts. In the below grade but dry parts, I might pour in some perlite. In the wet parts (near a drain/sump) I will call it good enough and leave it as it is for maximum drying potential.

 

[1750]

I knew enough to have rigid foam insulation (R-10) under the slab, but (maybe oddly) didn't know enough about thermal breaks to ask for the same thing on the below-grade poured walls. I kick myself, of course, because it would have been so easy to do this prior to backfilling!

In the finished area I had the wall furred out with 2x6, and with rigid foam against the poured wall and then rolled insulation to fill the rest of the cavity. In the unfinished area, it's just poured wall. It's all dry, and I was wondering if it would make any sense to put rigid foam against the unfinished walls.

Maybe it's worth it to try and still dig down next to the basement walls and slide sheets of rigid foam? That would be a lot of work, but it would only be 5 ft or so in most places.