DIY Foundation Repair

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Hi,

There is an old coal chute outside my house that was built with cement blocks and hasn't been used for decades. It's 2' x 3' outside the house and the blocks stick up about 3". Years ago I put a piece of steel on it and put cement on top of that which actually turned out to not a good idea because 1) the cement gets cold and 2) the steel causes condensation which drips and increases the dampness in my cellar, which is 80% crawl space and 20% open.

What I want to do is build a brick wall in the cellar right up to the house and fill that outside the house 2x3' hole in. I was going to get some estimates for it but I'm willing to bet people would want a small fortune for a job that I could probably do myself for a fraction of the cost, with bricks, cement, and some time. I can use old leftover coal and some dirt from the crawl space to fill in the hole as I build the wall. It's only 2 feet wide and about 6 feet tall from the cellar. Or maybe I should build the wall and then have someone fill the hole from outside.

Do you think this sounds OK for someone who's never done masonry work?
I need the wall to be strong enough to support the fill I put in it.
On the foundation there seems to be about 1/2 an inch of cement between each brick.

Could I build this wall with whole bricks without renting something to split the bricks with?
Should I use bricks with holes in them or solid bricks?
 
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JC1

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Are you talking about bricks or cinder blocks for the wall? I'm guessing this wall isn't going to be load bearing, but how will you get the wall to tie into the floor/joists above?

Is the sole purpose of the wall to control moisture, that is coming from that coal chute? Can you just insulate that chute with rigid styrofoam board to control the condensation?
 
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Agreed with pouring a wall. Form it up from inside with plywood and bracing. Drill some holes into the existing wall and stick some #4 rebar in them every foot or so, so maybe 5 horizontal and a couple vertical. Then build a form in the hole outside the house and leave it out 6”-1 foot so you can dump the concrete in. Brace everything well as wet concrete is heavy. Tap on the forms as you pour it and it should all settle nicely. That’s half a yard max for a 6’x2’x 8” thick wall and a couple sticks of rebar and a sheet or two of plywood and some 2x lumber.
 

Mr_Luke

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Are you talking about bricks or cinder blocks for the wall? I'm guessing this wall isn't going to be load bearing, but how will you get the wall to tie into the floor/joists above?

Is the sole purpose of the wall to control moisture, that is coming from that coal chute? Can you just insulate that chute with rigid styrofoam board to control the condensation?

Bricks.

I can insulate it and it will stop the condensation?
Yes, my main purpose for this is to stop the condensation. I was going to take that metal piece out and put a piece of thick plywood on it, and put a new thinner layer of cement over it but if I can insulate what I have and it will stop condensating, that will be OK with me.
 

Mr_Luke

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Thank you for the ideas but pouring a wall sounds too involved for me.
 

Mr_Luke

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Is the sole purpose of the wall to control moisture, that is coming from that coal chute? Can you just insulate that chute with rigid styrofoam board to control the condensation?

Yes. I put about 5 or 6" of cement on top of that 2x3'piece of metal to seal the top of the coal chute, where they used to dump coal into.
It gets cold and causes condensation inside my cellar.. How can I put an end to this condensation? It has caused mold around there.
Please tell me more about insulating it from the inside.
 

Mr_Luke

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I was able to get some insulation supports under the metal plate with cement covering it that was causing condensation, to hold a layer of pink insulation under it. I think that will put an end to the condensation going on in that spot.

It will not condensate any more because the insulation will be a barrier so it will not form?
The thick cement and the steel it sits on will still get cold in cold weather, but the insulation will prevent condensation?
 
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JC1

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Condensation will occur when hot meets cold. If you use the rigid foam board it should create a thermal break and stop the condensation. All joints should be sealed with sheathing tape or lap joints. I attached 2 inch thick pink rigid foam board and the condensation is almost non existent in the basement. How many linear feet need to be covered?
 

Mr_Luke

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How many linear feet need to be covered?

About 18" by 26".
I will inspect it today for any signs of moisture and if in doubt I'll yank it out of there and put up rigid foam board instead.
I have some of the rigid foam board. I sometimes use it for a home made portable sauna in my shower stall.

I just checked it out and there's no traces of condensation that I could see. Mission accomplished.
Now that part of my cellar will dry out. I even had slugs crawling up the wall there from the condensation moisture. I doubt they will survive now.

Thanks for your input.
 
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The condensation is just a symptom of the high humidity in the basement/crawl space. The moisture is still in there you are just seeing it condense on the coldest surface. Dry out the basement with a dehumidifier or seal up the dirt floor to prevent future moisture issues. The foam board sealed to the metal plate should help reduce condensation in that particular spot. Pink batt insulation isn’t going to stop air movement and will just end up getting soggy.
 
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watch videos by this guy,


Mike is my hero and a gawd, cement gawd :)
I have repaired by steps using his simple techiniques.
I am going to repair the approach from the street using cementall,
 

Mr_Luke

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Dry out the basement with a dehumidifier or seal up the dirt floor to prevent future moisture issues.

I put down a moisture barrier in much of it and a Air Titan7 exhaust fan to move the air down there. The RH seems to vary a lot depending on the outdoors RH. I tried running my own dehumidifier down there for a few days and it had almost no effect. I often have RH in the 80% to 84% range down there. It's mid 70% RH now that the outdoor air is drier. I was going to try to seal off the vented bricks in the foundation but then became concerned about radon so I didn't.

The foam board sealed to the metal plate should help reduce condensation in that particular spot. Pink batt insulation isn’t going to stop air movement and will just end up getting soggy.

That pink batt insulation was already feeling a wee bit damp so I removed it and put in 2 layers of 1/2" styrofoam board and used insulation supports to brace it up tight to the metal plate. Do you think 2 layers / 1 inch of it will be enough?
 
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I'm sure someone will tell me why i'm wrong, in fact i welcome it... but, if it was my hole in the wall that i wanted to fill in, I'd cover the opening with plywood on the inside, seal up the joints, and then from the outside fill 'er up with concrete.
call a local concrete guy, they may be able to fit in a smaller job/portion of a load, from a larger job they have near by... that's how my uncle got his 5'x10' patio poured...
 
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Do you think 2 layers / 1 inch of it will be enough?


I’d like to see a 2” thick piece but 1” is better than the batt insulation. I guess we can just wait and see what colder temps bring. 80%RH is quite high. The dehumidifier won’t do much if there are vents to the outside as you found out and the outdoor humidity levels are high. You need to block those off and get a radon test done to see if you do in fact have high radon levels.
 

Mr_Luke

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There was a slight fog on the underside of the styro board this morning. I'm going to add 1 more piece of it and see how that works. Then I'll have about 1.5 inches of it.

When I used the dehumidifier, I closed off both vents at the other end of the house and had blocked off many but not all of the perforated bricks.
But I also had a PVC condensate drain pipe coming out of my heat pump that was leaking water and didn't have any glue in the joints so I removed it and glued the joints together. That as well as the condensation I was getting under that metal plate over my old coal chute should help lower the RH eventually, along with my vapor barrier. I'm working on it.

You need to block those off and get a radon test done to see if you do in fact have high radon levels.

When I do a radon test, should I have the vapor barrier in place or remove it until after the test?
 

Mr_Luke

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Thanks again for the words of advice.

I got a 1" piece of styro board to add to what I have, plus I'm going to seal around it with Great Stuff.
When I get done with it there will no trace of condensation.
The 1" of it I now have in place is helping a lot but I think the additional inch of it will keep it dry there all Winter as well.
That spot has been a constant source of condensation and I'm glad to finally have it under control.
 
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Mr_Luke

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I’d test the radon however you will have the basement/crawl space setup long-term.

And do I test the air in my home or in the basement?
I hope it's not a dumb question.
It would seem to me that the test should be done in the living quarters.
 
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Everything I’ve read says to test the lowest level with living space. I know when we bought our current house they tested the basement which was unfinished at the time but with them knowing we were going to finish it.
 
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