Underpinning: DIY job ?

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Old 12-06-15, 07:49 PM
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Underpinning: DIY job ?

hey I have some questions about underpinning. If I should even attempt this myself.

Right now my house sits on piers. I guess you would call them. A could blocked cemented together every 8ft or so.

Anyway the previous homeowner laid cinder blocks around the perimeter of the house but did not cement them together. So I'm guessing they're not structural.

Anyway I would like to clean it up. I would like to cement them all together.

Should I pour a footing around it before laying the blocks? How thick?
How do you put the last block in between the sill and block under it?
 
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Old 12-06-15, 08:22 PM
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Should I pour a footing around it before laying the blocks? How thick?
It's not how thick, it's the depth that counts. In NJ, footings should be 3' deep. That's the only way you can make it structural.
 
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Old 12-07-15, 04:20 AM
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Since the underpinning isn't structural you could cheat a little on the depth of the footer but you definitely need a footer and not one that just sits at grade level. The top block can be a little tricky. I'm a painter, not a mason but I try to plan it so there is a little gap above the top block and then take care of that void with flashing.
 
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Old 12-07-15, 07:34 PM
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I'm not a professional mason, but I repaired a neighbor's block wall in the last subdivision we lived in (SW Colorado). The blocks made up stemwalls for his double-wide's crawlspace, and a bunch of them in just one area were collapsing inward from soil pressure and lack of adequate mortar holding them together. I relaid a total of around 35 blocks, and yes, the top course can be a tricky one. My system evolved into buttering the ends and top of each top block, then laying them in a bed of fresh mortar on top of the previous course. It took a lot of wiggling of the blocks to get them to slide in under the sill plate, and a lot of mortar was lost in the process (placing a few boards on the ground on each side of the wall enabled salvaging instead of wasting dropped mortar), but the end result looked much better than any of the other walls in the crawlspace.
 
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Old 12-08-15, 03:19 PM
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since this is not structural can i get away with doing a skim coat on the outside and spray foam on the inside? im sure it would cost a couple thousand to have a professional do it. and its a lot of work for me especially digging down 5-6' around the whole house
 
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Old 12-08-15, 04:39 PM
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So I'm guessing they're not structural
You already knew that what the previous owner did wasn't structural & we confirmed it.

Should I pour a footing around it before laying the blocks?
You're were right again.

can i get away with doing a skim coat on the outside and spray foam on the inside?
Not really. It's a waste of time, IMO.

im sure it would cost a couple thousand to have a professional do it. and its a lot of work for me especially digging down 5-6' around the whole house.
Both of those statements are true but there is another way out. Hire 2 or 3 day workers to do the digging. It doesn't have to be done all at once. We can explain the rest of the process, if you are interested but we will need some wide angled pics.
 
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Old 12-09-15, 03:00 PM
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Think of all of the free exercise you'd get if you didn't hire day workers to do the digging, but instead did it yourself.
 
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Old 12-10-15, 09:14 AM
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Why do you think waste of time? I just thought the skim coat for cosmetic reasons and spray foam insulation to secure them a little more and of course awesome insulation.

I would consider hiring a couple people but the part that sucks is my whole front of my house is a porch so all the digging out have to be done from the crawl space which is 3' deep at max. Would really suck. Your right doesn't have to be done all at once. Maybe I'll try a little section and see how bad it really is. I don't see a bad side to doing it right except the labor lol.

I think I got the jist of it but if you had any tips or anything else to add to process I'd like to hear it thank you
 
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Old 12-10-15, 09:20 AM
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I am a plumber I do enough digging putting in sewers and waters lol
 
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Old 12-10-15, 03:24 PM
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since this is not structural can i get away with doing a skim coat on the outside and spray foam on the inside?
I was answering that quote when I said that it was a waste of time. It seemed to me that your reason for posting was to solve a possible structural problem since the word underpinning was used.

I just thought the skim coat for cosmetic reasons
I don't know how cosmetics got in the conversation. They were never mentioned until today.
 
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Old 12-10-15, 04:51 PM
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yes i was asking a question.

instead of doing the underpinning since i dont need it strucually. do you think i can get away with doing spray foam inside and skim coat the outside. or would it be better to just do the underpinning

i just dont want the cinder blocks to fall out if someone touches them. thats why i asked if it would be ok if i skipped the underpinning and spray foamed and skim coated the the outside. and skim coating would just be cosmetic reason.
 
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Old 12-10-15, 05:04 PM
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instead of doing the underpinning since i dont need it strucually.
How did you come to that conclusion & how did spray foam take it's place? I'm sorry but I'm totally lost! We are going around in circles! Maybe someone else can help.
 
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