heat loss - basement cinder block wall - Insulate or not (from inside)?

If you insulate from the inside, the freeze/thaw damage will be worse. Sorry...

Yep, I understand your plan and was asking folks if insulation is good provided your plan succeeds. Because I've been considering it too.

If you look up the heat transmission factors the walls loose a lot of heat above ground and a lot less below ground. If your basement is staying in the upper 60s I don't think i would insulate it

I have a house built on about 50 ft of sand, and the water table (local rivers/lakes) is about 10 ft below my basement. Thus I have good drainage.

I also have a cast concrete walls, which were bare on the inside - and a huge heat sink during the winter.

In my case I propped up 2" foam-board against the inside cast concrete walls and studded the walls to hold it in place (and the studs allowed me to properly wire and finish the walls - on one side of the basement, the other side is still open studs and viable insulation and wiring: Someday...).

Depending on the state and local firecode (or common sense) you may have to put plasterboard (or another fire barrier) against the foam-board as it releases toxic fumes if exposed to flames.

I did not know that at the time I insulated and studded the walls (2001/2), and the local building inspector did look at my walls when I wired them without making any comments as I pulled a wiring permit, and they had to inspect the rough in wiring prior to my connecting switches, receptacles, etc, and prior to connecting to the breaker box (homeowners are allowed to wire if they get it inspected in my state).

You need to properly assess your situation and the possible solutions.

When I was a teenager some of my friends dug out around their houses and waterproofed and insulated their basement walls - as their summer project with their dad. Not that costly if you have the labor to do it yourself.

I wish you the best with this,

Perry

R-value ranges from 3 to 21? hahahaaha

Reflective (mirror) insulation has its place; especially if you can fill the space between the reflective surfaces with bubbles of certain gasses; or if you can create a vacuum between the surfaces.

Where I have seen it actually used (in the pure shinny metal mode with metal support pins between layers and no fillers) is to insulate the reactor vessels of nuclear power plants. It's one of those applications where cost really does not matter (and we spent over a $million to replace the mirror insulation on the bottom of the reactor vessel at my last plant (purchase price - not including installation: of course - we need metals that will not become radioactive or weaken due to gamma and neutron radiation).

If you can produce a vacuum between the layers.... you have a Thermos Bottle (or cup, etc.). Note that my wife really loves her new Thermos mug that I got her for Christmas. It works far better than all the cheaper "insulating" mugs that she has been using for years.

So, I believe that 1 layer of this bubble plastic with aluminum foil on both sides has an R value of 3 in normal use. Along that line... you likely need 7 layers to get an R value of 21.

Have fun....

The key to insulating and protecting cinder block -- or concrete block -- walls, as opposed to poured concrete walls is quite simple, really: you don't want the temperature in the wall to go below freezing or, if it can, you want the wall to be dry. Take your pick. Block constructed walls -- of whatever kind (includes brick, too, come to think of it) will fail if they are allowed to freeze in the presence of water, as the freeze thaw cycle will crack the mortar (if not the block itself).

Dry laid stone walls survive because they don't depend on mortar to hold them together. Poured concrete walls survive because they don't have any mortar. Block walls... not so much.

So. Ensure that you have good drainage on the outside and a waterproofing mastic on the wall to above grade. If at all possible, insulate on the outside; that will keep the block above freezing. If you have to insulate on the inside, double down on that outside drainage, and place -- and seal -- a vapour barrier on the inside before the wall surface. The outside drainage should be that waterproof mastic on the block, then a free draining layer (there are some molded plastic products in mat form which can be used placed nest to the wall, but not really necessary, also works), then coarse stone (1/2 inch to 1 1/2 inch broken stone) for at least a foot out and to a depth below the footing, with a perforated drain pipe to daylight at the bottom of the trench, and the whole thing protected from the surrounding soil with construction filter fabric to keep the soil fines out.

Don't skimp. You don't want to have to dig the whole thing up a decade later and rebuild the wall. That's tiresome.

I'm confused .... where is the water .... do you have a water problem at all? Also -- it's not unusual to have no snow along a building as in your picture ... unless wind driven I have the same on my well insulated house. To really tell what is going on you need a thermal image.

The best "first" defense is to always make sure the gutters are working and the slope is away from the house.

My current project included a new addition that was lower than the old one (deeper in the ground) -- this required us to dig out and into the old part of the stone building built in 1870. No foundation obviously. The lowest level of the new and old had to line up as there was a new slab w/ radiant going in -- white concrete as the finished floor. We had to protect this lower level so there was no possible water intrusion. ground or surface.

Required us to dig below the finished floor height -- install pipe and stones lower than the floor height. We also had to "stucco" the old stone walls w/ lime mortar (no cement) in stages as we moved up (it had to be done quickly). The lower holed pipe drains are under the stones in the picture and there is an upper pipe that takes all the water from the gutters -- this upper pipe drops down and meets the main lower 6" blue pipe way past the house -- the two come together in a "Y" to daylight. Actually the addition gutters do the same -- horizontal pipe for a section and then "Y". I also have patio drains tied into this system. One on each side of the building. We also did some underpinning

You can see the connections on the new addition.

Inside I have 1.5" of spray foam on the foundation -- PT 2x on the flats. On the old building we foamed the foundation inside .. the whole project is foamed.

Keeping things


dry is important.

A comment for @TAG -- If you do have a water problem in a basement -- water coming through the wall and getting things wet -- do NOT fall for the idea of slapping something on from the inside to fix it, however attractive the offer from the slick salespeople may be. There is a chance it might work, but a much better chance that it won't, and in some cases (if the wall is cracked or even more if it's dry laid stone, as some older ones are) it will make the problem worse. Water entering a basement like that can only be properly fixed from outside, with drainage.

Jamie .... if you see my pictures .. that's not what we did. The old stone part of the house was protected with lime mortar from the outside and then backfilled with a proper drain at the very bottom. All on the exterior .... I did skim coat the lower inside as well -- wanted it foamed to eliminate condensation issues. The bottom of that area was above the lowest part outside. The drains in the new area are inside under the slab insulation and outside at the footing -- all tied to larger pipes going to daylight.

The key with old building is don't trap any moisture .... Years ago people would spray old stone building with waterproof .......thinking it would help.

I find a thin film of foam works well -- inside below grade.

That's an impressive looking project, @TAG but I'm not a fan of injecting roof water into the ground adjacent to the foundation. I know you are piping it away somewhere (at least, I suspect you are) but these systems have a way of clogging/freezing and then it's No Fun.

At least an air gap would be good in the vertical pipe to drain, I think I have seen.