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

LS123

Hello!

I have insulated the supply steam pipes, and gaps in the basement where cinder blocks meet the wood frame of the house. Bottom part of my foundation is natural rocks about one foot plus thick, then cinder blocks about 3 or 4 feet.

Based on below pictures, I am loosing some heat from cinder blocks to the out side, ground...

I wanted to insulate the cinder blocks, but I noticed last owner had to repair less than hand full of cinder block joints ( possibly due to water getting in the cinder block joints and expanding them... during winter)

Not sure if I should insulate the cinder block section from inside the basement and do a visual inspection every spring / summer to ensure cinder block joints were not having water / freeze damages, and fix them each spring if there are damaged...

Also planing on getting snow, ice water from getting too close to the cinder blocks from out side the house...

let me know your thoughts about insulation cinder blocks from inside. below are pictures of two side...
Thank you!

Jamie Hall

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

LS123

thank you @Jamie Hall !!

LS123

thank you both @Jamie Hall and @Youngplumber .... yes ... spring / summer I will have someone come work on getting, snow / water away from the foundation.... basement is insulated from any cold air from coming in from out side... right now the basement still stays upper 60s min.... during really cold days... best!

ethicalpaul

To expand on the question a bit...let's say @LS123 is able to address the water from the outside with better drainage/ground pitch, etc

If the foundation is dry, is it then helpful or advisable to insulate a block foundation from the inside?

LS123

thanks @ethicalpaul , I figured work on getting water away from the walls in the spring and see how it looks during next heating season (hopefully the water freeze / and thaw should be gone ) .... then insulate the cinder blocks from inside to reduce the heat loss...

Larry Weingarten

Hi, I’m wondering if the best approach is to trench around the outside, then insulate and waterproof. Adding a protective layer over the waterproofing would be nice as well. Is there a way to install drainage that can run to daylight?

Yours, Larry

ethicalpaul

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

LS123

Hello @Larry Weingarten , yes... I hope that would be the plan from someone I plan to hire in spring / summer. yes, one of my friends long while ago had someone come and do some work like that, they had either paint or cement base (water resistant )paint and some plastic liner put in about 6 feet deep all around the house.thanks and best!!

LS123

@Youngplumber , @ethicalpaul , and @Larry Weingarten ... I think most water will be away from the cinder block wall... there are so many product available to block water getting in between cinder blocks (from out side) and expand and messing them up.... thanks all for your feed back.... when I find a pro... will update all with you my plan... best and thank you!

HomerJSmith

Well, looking at your pictures, you are obviously loosing BTU's thru the foundation. Your melt away of snow from the foundation tells the tale.

To dig down 8' and waterproof the block would be the best option and then insulate the outside of the block. Mucha, buckos.

If you don't have a high water table and good drainage, You might consider this:

Dig down 2' around the exterior perimeter block, out 3' from the foundation. Taper this trench 1" per foot from the foundation to the outer edge of the trench. Lay in the trench 1/2" Hardy Backer Board from the foundation to the outer edge of the trench. This would funnel the water away from the foundation. You could cover the block from the 2' level up the block with the pink insulation board and cover it with 1/4" Hardy Backer Board for protection, back fill. Gutters are very important.

I would insulate the interior of the block wall with Urathane (Rmax or Celotex) or the pink insulation board.

This is the way I have done it. I took 3/4" plywood and cut it into 1-1/2" strips 8' long.
I glue the strips with construction adhesive and nail it onto the block 16" O/C. I fill the space between the strips with the insulation board. I then screw 5/8" drywall to the strips.

Do what is economical for you.

LS123

thank you @HomerJSmith , I do have few neighbors with small backhoes, that have helped me put in the past... I am sure I can ask for help and hire someone or two to help out and get the water away from the hose.... this is also a wonderful idea!

ethicalpaul

Check out this video which I found very helpful to explain the ways to dry a basement presented in order of best approaches. Try the easy stuff first! (grade and runoff control)

https://www.youtube.com/watch?v=1u90y72RHgM

EBEBRATT-Ed

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

LS123

thanks @ethicalpaul for the video clip.... @EBEBRATT-Ed , yes the basement is much air tight, I used great stuff form and fiberglass to insulate most part of the basement...steam supply pipes are also insulated..., on a cold day... or warm day out side... it keeps basement comfortably warm... it was getting too hot... that is why I end up insulation the supply steam pipes... best!

PerryHolzman

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

LS123

thank you @PerryHolzman , luckil yreally dont have any significant or water coming inside the basement.... I went by heat loss from cinder blocks above the solid real rock foundation... I noticed about three small sections no more than three joints between cinder block was repaired. house been around 70 + years. I probably get a formal estimate and what needed to be done first, including taking all the heatinghelp members feedback... I intend to used reflective heat shields like below.. it seems to have R value (enough to reduce or prevent much of heat loss) and easy to work with. I already have most basement with fire guard grade sheet-rocks... and it would be easy to put fireguard sheet rocks on top of this flexible` insulation. I will first make sure as long term solution to get any snow, ice, water way from near basement walls out side. then wait and see if there are any signs or water / moisture *outside walls) before insulating the cinder block part on the foundation from inside (next heating season)
Thank you!


https://www.lowes.com/pd/Reflectix-R-21-33-3-sq-ft-Unfaced-Reflective-Roll-Insulation-16-in-W-x-25-ft-L/1014123

ethicalpaul

R-value ranges from 3 to 21? hahahaaha

LS123

hummmmm.... @ethicalpaul ... I m new and learning ... I see below.... i seen the cost of R-49 insulation and nearly passed out... Am I missing something?

"Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces. See the Department of Energy's (DOE) ranges for recommended levels of insulation below."

PerryHolzman

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....

LS123

thank you @PerryHolzman .. once I make sure water is no longer an issue for cinder block walls during next season, I can always put higher R value insulation, mold / mildew resistant sheet rock.... I was considering above insulation because its easy barrier and still better than naked cinder block walls that loose heat. I have nearly a foot available from rock foundation, then about 3 or 4 feet of cinder blocks on top of it in the basement.... best! LS123

Jamie Hall

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.

LS123

5thanks again @Jamie Hall ... I am looking forward to this project is spring / early summer.... at least three of my neighbors have small backhoes that dig at least 6 feed down... although I should be good with 4 feet...no skimping...will make sure water proofing out side lasts for 20+ years min.... I like to have any job well done... just in case i might be at this house for next 20 years.... looking at long term resolutions, energy conservation, etc...

TAG

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.

LS123

@TAG , simply put... no I do not have a ongoing water problem... I just happen to notice heat loss from cinder blocks (that is above real rock foundation... person who used to own the house, had built it and kept up with it.... in the whole basement there are about three or 4 places where it appears to be work done on cinder blocks damaged motor in small sections...I prefer long term solutions... will move forward with making sure out side work is done in spring... hope this is little bit clear regarding my post... thank you for the details above...

Jamie Hall

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.

LS123

@Jamie Hall thank you! your experience, feed back have saved me from converting to hot water system from steam based on respectful.. but money driven company... many moons ago ( may be 12 months give or take) saved me 23K to convert to hot water system from steam) my steam system rocks!! never will I consider changing to anything different..., I must also give credits to @Charlie from wmass ... whom I look forward to meeting in sometimes .... @Erin Holohan Haskell please note that heatinghelp site is wonderful... especially thanks to two wonderful individuals, and so many more I cant list all... each one of you know that your contributions play a significant role in educating novice people like I....

TAG

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.

HomerJSmith

Water is the real culprit, here. Water will convey heat energy a lot faster than dry air in a block wall. You may not realize that the wall is damp. Buy a moisture meter and laser thermometer from Harbor Freight, They're cheap, and measure the moisture in your walls and the temperature, too. You may well be surprised. Heat energy travels in a straight line to what ever is coldest.

If you don't have lime staining on the block wall you're a step ahead.

ethicalpaul

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.

TAG

The downspouts are connected to a 6" pipe that wraps around the addition foundation -- it's not very big. This 6" pipe go to daylight at a wall ... all 6' down. The other feeds don't just drop into this pipe -- they do so downstream.

The downspouts now go into 4" CI fitting -- the kind with the bell

LS123

wow @TAG ... that looks like some serious effort and work... each person probably have different situations and conditions where they may get water damage... as I mentioned in 70 years... I only see about 3 or 4 max work done on the cinder block mortar (with in last 70 + years... the person who built the house was very hands on.. he had kept up with maintenance of the property well.. thus I am still having a efficient (used to be coal.. now ... with a efficient oil burner.. and steam heat....) .... I am kind of person... perhaps get too hyper focused... look at long term solutions, I probably do spend little bit more that I should... (it seems like my hobbies to work on interesting and challenging [by trade .. I mean for work, that gave me a check was hands off for so long)... but in life projects... (safety is always first, and had been)

just to conclude this subject.... please feel free to continue to give me your feed back.... wholeheartedly I trust and honestly have learned from so many of you..... @Steamhead , @Jamie Hall , @Charlie from wmass , @JUGHNE , @EdTheHeaterMan been and so many other have helped so much understand my steam heat system.. etc.. I thank you all for making this forum so helpful...u ALL rock!!

TAG

With old buildings you have to be careful -- stone looks inert and oblivious to environmental conditions. It's not .. you don't want trapped water. When this building was built in the 1870 they used local stone ... same with the slate roof. Today many common stones used to construct old building would not be used as they are not hard enough ... the cost to quarry and install poor stone being comparable to good.

The OP mentioned water -- that's why I added. Also -- it matters if the lower level is going to be finished. This is a church that will be my residence .. with a very finished lower area that can not get went or even damp.

LS123

@TAG thank you... information is definitely helpful to me