Help! – While parging the outside of my 1940’s colonial block foundation (to control some minor surface deterioration), I dug down and found a block that crumbled under light scraping. I’m now digging down 2 courses only to find to entire row in dire straits.
As background, the yard tends to flood. Also, about 16″ down is a thick layer of furnace debris as the house must be built on the site of an old dump! Is this material reacting acidically, and eating away at the block?
Can I sue somebody? Should I bury it and sell?! Will my insurance cover it!?
I feel sunk! ~ Anyone want to take this on?
Replies
You might be able to parge/repair it in sections.
Could you excavate full depth in one location and see what it really looks like? I am not familiar with acid attack bu #### sounds plausible. I'd explore things a little more before you panic. You say the house must be built on the site of an old dump. Is there some other evidenc besides that" Ashes were often used as filler underneath basement slabs, Perhaps that is all it is. Maybe it was just a layer of that materia and further down is not the same.
Like I said, I'd dig a test pit full depth. Pictures might be helpful too.
Good luck.
I appreciate the "don't panic" note - cuz that's what I felt like.
The ash by the way is all over (under) the yard.
I think I'll rent a small excavator and see the full extent. At one location, I did do small parge/repair work- filling 5 - 80 lb bags of concrete down into the cavity of the block. Is that doable?
If it's more extensive I'll fabricate a bearing wall to support the house from within the basement & remove the entire course or am I now way over my head?
Thanks again for the help.
May God bless you.
Does the house have a full basement? How do the blocks look from the inside?
I once owned a 1920 house with a block foundation. It was parged on the inside and outside, which should have given me a clue when I bought the place. Well, that and the fact that one entire wall, from grade level up, had tilted noticably outward. But it was a nice house in a great location, so my wife and I weren't being too picky.
When I started probing around from inside the basement, the parging fell away, revealing just piles of sand where concrete blocks used to be. Other blocks were intact, but would crumble easily.
For the worst areas, I built forms inside the basement and "poured" (one shovel-full at a time) reinforced concrete to make the walls thicker (with a couple concrete buttresses).
For the rest of the walls, I parged with a lime/portland/sand stucco. This was primarily cosmetic, to sell the place when my wife and I separated. The home inspector raised some concerns, but the buyers wanted the house enough to accept whatever needed to be done in the future.
That was 10 years ago, and the house is still standing. And the new owners haven't done anything with the foundation, yet.
Follow the previous posters' advice, and don't panic.
Allen
It's a full basement. The block on the inside is flaking in certain areas. I'm planning on parging that with a waterproofing cement, like Thoroseal or from Quikcrete.
Is parging usually a sign of problems? Is it a good practise to parge block from initial construction?
Parging is not necessarily a bad sign. It may even be standard practice in a lot of areas. The "clue" I overlooked on my house was the sloppy, unprofessional parging, inside and out.
On rubblestone foundations, it's not uncommon to see parging or stucco applied perfectly flat, then struck with horizontal and vertical joints to give the appearance of fine ashlar construction.
I think the blocks used in my 1920 house were faulty ... probably a bad concrete mix (not enough cement? or too fine aggregate?). Plus poor drainage and wet soils. The cores were left empty, which may have been standard practice at the time. A lot of the blocks have turned to sand, but the house has been standing for 86 years, and isn't gonna fall down anytime soon.
I wouldn't worry too much about your foundation. You may want to probe around to get a sense of what percentage or specific areas are failing. If it's primarily blocks in the upper few courses, you could fairly easily rebuild in sections, I think.
Allen
You know concrete block manufactured in the '40s buried in wet soil may just have met their life expectancy.
Patching, parging and the like, is only cosmetic but non-structural in value.
Consider jacking the house and replacing the foundation entirely.
For a DIY'er consider an ICF basement.
My 2 cents.
“[Deleted]”
Insulated concrete forms, stay -in -place Expanded Polystyrene R22.5 value blocks.
Lots of choices, Nudura, Logix, Integraspec, Amvic, Reward, Arxx are brand names.
Find info at <http://www.icfweb.com>
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Appreciate the note. Sorry for the late reply - family called!
I'll scrounge around for that 50g's I put somewhere - now... where was that?
Hey, if you DIY, find 25. :-)
Any good place to learn how to jack up a house, even if it's only a 1/2"
I do home improvements, if only for the last 5 years - but i learn fast, have a good attitude, and my own tools - he, maybe I'll hire me.
Go check out the local building movers contractors.
That industry has some very specialized hydraulic equipment, but you can DIY with simpler gear.
You can lift with a good hydraulic jack. Rent, until you find the right unit for your job, then buy.
Holding the lift stable is the key.
Concrete deck forming scaffold with "U" heads can be rented and will hold tons. It would save on wood cribbing........ that can be unstable.
It's a matter of identifying longitudinal loads and point loads. Breaking them down into a grid, estimating the load, and planning each pier or scaffold. You could get a structural P Eng to help you with that, if you are unsure.
It much tougher to move a building than to raise it a bit. Accept it that there will be some minor damage to finishes and such, but your reward will be by far a better home, and if you do use ICF's for your new basement, you will smile everytime you head down the stairs, because the comfort level is incredible. Cheers.
Great book that shows among a whole bunch of other stuff, jacking, holding the house and foundation repair:Renovating Old Houses by Nashhttp://www.amazon.com/gp/product/1561585351/sr=8-1/qid=1149644283/ref=pd_bbs_1/104-3816428-7012729?%5Fencoding=UTF8
Don't know why, but I was thinking ash would tend to be caustic rather than acidic. Acid could definitely be a problem if that is the case. Seems like a quick soil ph test would tell you the answer to that. Won't jack up your house though.
Good luck!
Thanks folks - I've now dug along 2 sides of the house, down to the footings. The bottom 2 courses of block crumble under the pressure of water sprayed from my hose. Primarily it's under a 20 x 25 1960's addition, shaping my house in an "L" design.
So I'm at the point of learning to lift and replace! I can't see how this could be done block by block.
Interestingly, the slab is above the 4 lowest courses. Struck me as odd. Does this confuse issues any?
Thanks again for all the help. This is my first go 'round posting sutff and all the forums are a rip to read.
How is your project goin ?
You know, I appreciate you asking'.
When I last left you I took the garden hose and sprayed down any block that would give under that "extreme" pressure. Reveling the bottom two courses needed to go.
Not having $25-$50k, to jack the house, my brother-in-law (I hate this part) said to chisel out the front half of block and insert a solid core block in its place - block by block. Having to also work for a living and be a great dad simultaneously, I haven't fully thought this through. - but it doesn't seem correct or feasible.
I have been thinking how to create a form and just pour tons of concrete into the dilapidated sections. That seems to me to be the best option.
So anyway I haven't moved much forward yet.
I have no idea if this would work or not, and I am not a structrual engineer so take this with a rock of salt.There is a process called mud jacking used to raise concrete pads that have sunk. Maybe this would work with the right forms? Since you probably can't get any rebar in, you might have to use a reinforced concrete or something.