Foundation cracks.

[Slowgsr]

Well i know this is a bit off topic, but since there's lots of diyers in here who pay attention to this I thought I would ask.

I have an older home, 1970s, cinder block foundation. I gutted the basement, and I notice some cracks in the blocks, most are step cracks in various places, there is one spot where I notice a vertical. Now maybe they were always there, and I'm just noticing them now more as I'm getting more up close with the wall doing the framing.

The basement doesn't leak, there is an exterior rubber water proofing and I doubt these cracks would be visible through the waterproofing, I actually probably wouldn't be able to notice the inside cracks if the wall wasn't painted, which was done probably 20+ years ago as it was behind existing finishes.

My grading is good, I have well draining soil, I don't have a high water table, and my downspout extend at least 10 feet. The exterior brick is all good too, nothing substantial there.

The cracks are very fine in the morter lines, and there's no horizontal ones, no wall bowing. I have no up stairs drywall cracking and all my doors and windows still open normally. I would say at the widest point the biggest crack is less then 1/16"

I'm in Ontario canada, so we have freeze thaw, it gets cold, its also very dry right now.

So anyone else notice small hairline cracks in their older block foundations? Maybe its from past settling, or expansion and contraction? I think I'm just being overly paranoid maybe?

Thanks.

 

[Kaizen]

I have a field stone foundation and it happens. You could remove the mortar and re point if it really bothers you. It most likely is from original settling. You could pick a few and mark them now and take a picture and see what it looks like after the thaw and see if there are any changes. That would be a little more concerning.

 

[Hilltopmasonry]

If your walls are not pushing it all and the cracks are just hairline cracks then I wouldn’t worry about it simply because it’s just expansion and contraction of the soil putting a little bit of pressure on the wall

you have a rubberized waterproof membrane on the outside? then I totally wouldn’t worry about water problems since the membrane is flexible


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[Bretny]

The real question is are any of your blocks filled with concrete, like they should be.

 

[maxpat82]

The real question is are any of your blocks filled with concrete, like they should be.

like they should be today.
in the 70's nobody filled blocks with concrete.

 

[Slowgsr]

They are not filled, nothing from the 70s,80s is here, I could see that combined with rebar adding a lot of strength mainly against dirt and frost pushing on the wall. I wonder if the footing even has any rebar in it?


The older blocks however are much thicker then modern blocks.

 

[connorm]

Is it along the joints or are the actual blocks themselves cracked?

If you're worried there are places that spray foundations. Line X (the bedliner) is popular around me, the foundations are literally bombproof after.

 

[Bretny]

My friend has a 70s built house. He had a long horizontal crack with two stair step cracks. He found the wall bowed in, many holes in the outside of the blocks and major water dammage to the exterior of the wall. Many tens of thousands of dollars later he has a rebuild block wall with proper exterior drainage to the point that he dosnt need a sump pump. The cheapest part he did him self. He jack hammered holes into the floor/footing and cemented in vertical I beams connected to the joists. The wall has not moved.

 

[machsnell]

No bowing is a good thing.

No water damage is a good thing.

Smear some Portland slurry over the cracks and see if they crack or move. If you have the time for that.

If you are finishing walls i would want to know that there isn't movement which it sounds like you are ok but would be nice to know for sure.

My 1960s house had a basement wall that was bowed on 2 sides, one side was bowed about 1.5" out of plane. Water was coming in in several areas. Not too awful but wet puddles on concrete in 2 areas kn a heavy rain.

When I dug around the outside of the house down 12 feet to footing there was no foundation drain nor stone around foundation. The blocks (12") weren't filled either.

I put in drain to daylight and coated and installed 15mil plastic and drain board and took the 57s up to a foot plus from finish grade.

When excavated I pushed wall out slightly and started to fill cells from inside house and install rebar and fill with concrete. You just cut holes in blocks and push supply concrete un hole and move section of rebar to help settle.

I did this every couple blocks less in lightly cracked areas and more in the heavily bowed areas.

It was slow and painful but I want to finish and didnt want to worry about it again. Ever.

I skim coated the cracks with Portland slurry and 4 years later not one drop of water nor moisture in blocks and none of the small cracks have even broken the skim coat seal of blocks.

Peace of mind I love having.

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[Kevin54]

Most likely settling from a few years after it was built. If your walls don't bow in, if you don't have any water coming in, patch it or ignore it, since you have an outside water barrier. Stud the walls, and take over the area as the man room.

 

[kbs2244]

It sounds like normal settling.
It happens in the best built block walls.
Above or below grade

Yours most likely happened in the first year of the house being built.
I would say you are fine.

 

[Slowgsr]

It's been very cold here. -25c at night, I only have about 5 feet of block in the ground. I set all my interior framed walls with a laser, and they aren't bowed, and these cracks I have, are small. Like... Hairline, very very fine. My dad couldn't even see them. He told me everything will move especially from extreme cold to hot,

No water. Good drainage, gutters away from the house, etc. No gardens or trees near the house,

The walls will be spray foamed very soon. So I don't have time to watch them.

Thanks for the advice and feedback, ill carry on. I'm probably just paranoid, but I'd rather get more information when I'm in doubt, and not always advice from a company trying to sell work