Home Improvement Advice? Heating a Cold Basement

[Grendel]

IF you feel you need to add heat without insulating then you want to not use convection heating (heating the air) because you will be fighting a losing battle. IF you want to locally heat then use radiant heat source. This will allow the heater to heat objects and you directly without having to first heat the whole environment first.

[Tarsun2]

I'm not a contractor and this is not something im an expert in but, i would not want to move the heat from my living area down into the basement and out the foundation.
What i do know is that keeping your feet warm makes a huge difference. So much so that if you wear socks to bed, you can get away without that extra comforter.

if it were me:
foam mats. (like the interlocking squares you see at costco and whatnot) and a small ceramic heater.
turn the heater on when you're doing laundry and off when you leave. They heat up quick and are very directional.
you're probably looking at $50 all said and done.

trying to heat the basement in its current state is like adding a second coolant reservoir because you have a leak in the radiator. You need to fix the issue rather than coming up with a work around.

[nobbie333]

Check where you are losing the most heat by borrowing or renting a thermal camera

[Diomedes]

Alright here's some pictures for everyone.

First is an overview, you can see the general layout. between the two blue poles, you can see the chimney that runs all the way up and out. That's not used anymore, and all the ducts are blocked off. You can see some windows on the left, there are eight of those, but they're just a few years old and seal quite well. (You can see where ceiling tiles have been removed over the years to get into spaces as work was being done. For whatever reason, the previous owners installed fixed tiles rather than a drop ceiling, so doing work is a pain. We just get rid of them when we remove them, rather than fighting them back into place.)


Here is a wall. As you can see, it's concrete all the way up to the rim joist (recently insulated), with a few feet above grade.

[Siress]

You can ignore the ceiling if your intent is to keep the basement at a temperature lower than the floor above it. In this case, the ceiling is actually a heat source for the basement. Probably cold for anything but carpeted flooring above, though.

It looks like someone may have actually sealed that concrete already, as the color is one of the common tints for it; basically beige/"bamboo" and white. That's a win.

I'd go ahead and frame the wall to the left in the first photo - at least. You have a lot of plumbing and electrical there that needs to be protected. You can then use fiberglass insulation instead. You won't need to add drywall, but at least add a sheet of plastic to add some puncture resistance over the paper. What you save on foam board you'll spend on lumber (and then some), but you'll have a lot better insulation (R-13 over R-5) and have to put in a lot more labor - with more tools involved if you need to save time. If time is no object, you can get it done with a saw, hammer, chisel, and hammer drill. A staple gun, rotary saw, nail gun (+ compressor) , and hole saw kit will cut down on time dramatically.

If you don't use the windows, I'd create some removable insulated inserts to cover them. 8 of those windows is enough to address.

[Mr. Hick]

There are other, More temporary options as well. When you look at the over all cost of the entire project have you considered a vent less propane heater? Do you have the availability or capability to add a pellet stove?

[Diomedes]

Okay, so a bit of backstory to help everyone see where we're at: In May, we added solar panels, and the idea is to be all-electric. BUT! We had at the time an oil boiler with a hundred-year-old cast iron single-pipe steam heat system. And the plan was to replace that in 5-ish years with an electric heat pump system, and expand the solar setup at that point to compensate.

But then last winter the steam system kicked the bucket. So we had to replace that this past year. But there was an unintended consequence: the boiler and steam pipes were keeping the basement warm, so now there's no heat source in the basement.

So we've done some work to deal with this. We had the rim joists insulated (you can see the lower edge of that in the 2nd picture), and I sealed a crap ton of gaps and cracks and caulked around the windows to seal any and all gaps I could find.

But it's still cold, and I think it's mostly because of the above-grade concrete walls.

So we want to keep the place warm, but no gas, no oil, etc. If we're going to add heat sources, it's going to be electric. So the question it seems is insulation vs. a heat source, and it seems like insulation is the way to go. But ugh. More work.

[Magmoormaster]

Architecture student/residential drafter here.

It's not just the above-grade stem walls, it's all the stem walls. Insulating just the above-grade bits isn't going to be the solution, you need to insulate it all. It is certainly more work, but obviously just adding a heat source is going to be incredibly inefficient if you're dealing with this level of heat loss. Furring out the walls and adding some real insulation won't be the worst job in the world though.

You should also look at the windows themselves; I know you said you caulked the edges but in most old homes the windows might as well have a negative R value. Upgrading to a newer window system might be a good idea, especially if you're already doing all this other work.

[Diomedes]

The windows, fortunately, are only a few years old. When we bought the house, it had the hundred-year-old single-pane wood-framed leaded-glass windows. Those are all gone, the only extra sealing I did with the windows was where the OLD outermost wood frame meets the concrete.

Another consideration is the ceiling. If insulating the basement walls would be a bigger project than I care (or have time) to tackle right now, what do y'all think about closing those gaps in the ceiling with the intent of blocking off the cold basement from the heated first floor? We do have a TON of spare ceiling tiles. That won't solve the basement problem but would that maybe help with the cold feed and draftiness of the first floor?

[Siress]

It's tough, imo, because the joists themselves will wick heat from the floor above. I'd add heated flooring instead.

[Grendel]

Short This Old House video, properly insulating then adding a small electric heat source is most likely the best way to go and not have a lot of regret later. You only have to insulate that which you are using. If that is all of you basement in the pictures then insulating really is not going to be that expensive.

interlocking gym mats on the floor would be an excellent idea to for the floor

[flyweightnate]

Avoid doing any framing right now. Lumber is at all-time highs. I had to get some 10' studs to frame in a laundry room in my garage (wife got tired of sawdust on the washer after only 3 years), and while I'm glad I did it, the studs were something like $6 each. It's insane.
I'd recommend a trial membership to Fine Homebuilding, and crawling their archives for their ideas, but TOH is a good source. Furring strips and foam board has two benefits - first, insulation, but second, that little air gap in the back is good for moisture control and creates a little bit of a thermal break. A lot of foam has tongue-and-groove edges, too, making it a good air seal even without tape. My experience is that foam comes in a touch cheaper than fiberglass batt per square foot, but quite a bit more per R value.
You'd be amazed the impact a tiny draft, has, so keep an eye on that, too, as you insulate. I've seen everything from foam gaskets for receptacle covers, to sealant caulks foams to put behind doorjambs and baseboards. People who know more than I do say it's worth it.

[Siress]

Seconded. I use more Great Stuff foam that I'd like to admit - mostly to cut down on drafts, add some fire resistance, and - with addition of steel wool - to block anything that could be a pest/vermin thoroughfare.

Basically, I'll use it to fill any gap in the framing - like around door frames, along joist seams to drywall/subflooring, a solid inch or more around junction boxes, any foam board to foam board interface.... I go ham with that stuff. Just have to have a good applicator gun, the solvent near by and know when to use the solvent vs letting the stuff dry before removal.

[Diomedes]

Okay, so reading through this and elsewhere, it seems like the bare concrete is the problem - it's a giant heat sink in the winter. And the biggest surface area of that heat sink is the floor. So...

What do y'all suggest in terms of some kind of floor covering? Trying to keep this as inexpensive as possible, and it is, fortunately, a dry basement. So anyone have any easy-to-install suggestions?

Just spitballing, something like this work?

[Siress]

Heat rises, so walls first and foremost. Insulating the floor will only reduce heat flux conducted through it as you walk around. It'll be like the rugs are now; technically just as cold, but don't pull heat away from you as quickly because it's a decent insulator.