How To Add a Footing to a House Foundation | This Old House
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- เผยแพร่เมื่อ 2 ธ.ค. 2024
- The foundation on our house has no footings. Kevin and Mark McCullough fix the problem by pouring a buttress along the foundation.
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How To Add a Footing to a House Foundation | This Old House
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We encounter this in Seattle homes all the time. As a general contractor who specializes in repair work this it is an improvement to the foundation but it's not the best way. Rather do four foot sections leaving 8 ft of soil between the sections.. Excavate for an entire new footing directly underneath the foundation so you have a direct load transfer onto this new block of concrete. When you have the 4-foot hole dug put rebar in your medium sized Roto Hammer and drive it into the adjacent soil. Cut the half inch rebar in 42 in length. Hammer it into the soil 21 in so you will have your 40 rebar diameter lap for tying the next section into it. Sad to see he did not use a concrete vibrator
Bought a POS cottage from the 40's. It's had at least 3 renovations over the years. I'm changing floorplan because roof needs replacement and adding a basement for a walkout to the lake.
My builder and I determined it would be cheapest to tear off the back 24 ft since roof replacement and large windows will being going in.
It has a very small utility basement in the center of the house with short ceiling. This small basement was added at some point and it's 2-3 ft off the original wall/footing.
My plan was to expand the old basement all the way out and remove the old stone masonry footing. Digging out 4 ft sections to add new footing and wall using the new insulated concrete foam forms (icf) to pour those sections. On corners I was going to do 3 ft and 1 ft.
Any suggestions? Do you think this is doable?
I am going to assume a structural-engineer specified the modifications
implemented in this clip.
I've seen a town house get an expanded basement that sounds like what you wanted, but it's been two years since your comment!@@StreamingF1ydave
YUP, no vibrator. I've learned a lot about concrete, and that was my immediate thought...after processing that they'd dug out the *whole* thing.
You think he’s gona use a vibrator when he doesn’t even use a pump. He’s got man power wheelbarrowing it all in. He ain’t using a vibrator he’s just gona tap on the forms with a hammer😂
Since an important part of this is to have the new concrete "slip" under the existing foundation, why didn't they use vibrators to facilitate with that and reduce any air bubbles that would form under the old foundation?
It's a strange design intention. Partial underpinning. But the probably used scc.
I had to redo a foundation that was poured with half a footing like this about two months back. The side that didn't have the footing started tilting out. This was probably due to this footing section that was added being deeper and on firmer soil. We had to create a footing on the other side. We drilled and epoxies rebar into their side that had the half footing. So now they have a full footing under the wall.
I had to log in just to put this comment on an observation, after I logged in I did catch that he mentioned that this was also done IN LIEU OF the house weighs less because the roof and other things were missing. BUT still there was risk (like if it rained hard after you removed dirt under the walls) when you start removing dirt under the walls you lose the weight limits on the soil which means the walls could fall into the ground. I am researching putting footers under in my case, older stone walls. I am not sure if I am going to do it, but I am hypotheticalizing how I would do it if it comes to it. I would do 2-4 ft sections, but there is no exact science because I cant find any information on how much weight these walls can hold per foot/height of these stone walls, plus there are other variables like hidden cracks, mortar deterioration etc.
How could (or should) I do this to a slab foundation?? I have a guest home on my property that had a slab foundation poured on some raised ground but they didn't pour a footer. I can dig around 3 sides of it and put one in fairly easy but down the middle were they joined the house to a different slab which is 18-20 inches lower, I can't. (well, not 'easily') I have had the upper slab foam jacked but I'm thinking a proper footer on all the edges of the upper would be a good idea....thoughts???
I like how Mark and Kevin are wearing the same shirt.
Is it correct to lay a conc footing on an already existing strip onc fonudation .Instead of putting the footing and concrete it before the strip concreting, I found out that my Mason already pour a con that area, so I want to place the footing on top of the strip . Is it correct?
Is this as strong as underpinning in 3 foot sections? The foundation walls sit on just a few inches according to the contractor. I'm sure the engineering was done correctly, but wonder how it compares to underpinning.
I'm with you. I've never seen underpinning done this way, where it only goes halfway under the width of the existing foundation. The load will not be spread downward evenly, in my opinion. Better to do it in 3-foot sections at a time, going fully underneath the existing foundation and even past it, if possible (but not necessary). Rebar and all that , of course. Then continue on to the next 3-foot sections.
Every time I watch one of these videos I wonder what the cost is of the job, they never mention it.
A hell of a lot more than your normal homeowner can afford. Check out some of the Mike Holmes shows where he lists the costs minus their labor and it will blow your mind.
Costs vary widely by your area and by customizing the application to your home's specific needs.
Because this type of work doesn’t have a set price, every contractor will charge different prices and there’s so much to customize and adapt that giving you a price isn’t possible.
I know it may be a ridiculously wide “estimate,” but I would bet somewhere between $20k and $30k if you left out the other demo that helped with the process. I would assume with somebody that is working on a home like this it kind of is what it is. Good for them!
@@goiner940 try more like 50k or 60k after all the manual labor and what not
Make these videos longer
I wish you'd did the whole video, forms and everything.
Great video! We recently purchased a home that is over 100 years old . We recently started installing and interior weeping system to help with drainage and water issues . We realized when digging that we cannot locate one of the footings. This would be the footing along the back of the house . We're worried there may not be one there . As the more we dig the more dirt we find ! Is this common ?
My house was built in 1865. I am currently underpinning my foundation, I have found that there is not a footing just stones that were laid in a trench and mortared together.
Yes houses built in the 50s had 12 inch thick foundations built with bridge concrete. Very strong stuff. Because of the thickness they did not use footing.
This footing, although not a real FULL footer is still better than nothing, i do hope you added a drainage system to the inside or outside of the home.
Did they then dig down on the opposite side, and do the same thing, to cover both sides of the foundation wall?
Yeah I wished they showed blue prints of the upgrade. From what they showed in the video, doesn't look like it. So the footing instead of looking like an upside 'T' now looks like an 'L'. Now I'm no structual engineer, but the width of the new footing still didn't look sufficient to code.
No, they didnt. Something I would have done though
I wish my foundation fix could be this fast.
Were the pins epoxeyed into the existing foundation or simply drilled and stuck in the holes. There are a couple things I'd have done differently but looks good.
This job , would require a engineered plan , residential or commercial. Structural is something that needs a inspection before the pour and after the pour . Lots key elements missing in this video. Anyways your right about the pins having to be epoxyed in.
Cheers.
The rebar can be driven in to the old stem wall
@@fredgarvinMP it is supposed to be driven into the old wall as an attachment. Whether it was epoxied is the question. Pins are nearly always epoxied unless stipulated not to be. In the past, we have made u shaped pieces of rebar to do this same thing. Pins can be drilled at an angle into old work for a little more attachment depth.
How come you did not vibrate the pour?...
I renovated a Barn into a house and had to pour foundations under... we ended up removing 15 yards of dirt 3 yards of rock and still had to drill and rebar pin into bedrock because we could not get down to code depth.
How do they make sure the undercut part gets full of concrete? Wouldn't just pouring the concrete in leave a void under the existing foundation where the undercut it?
I think that's why the concrete looks so, so wet.
Great video, very informative!
...this is my question. And I do not see this issue addressed in any of my research. When creating a footing in an existing basement how does one account for the infrastructure already in place I e my hot water heater, etc which are all in place very close to the wall leaving no room to dig a footing can someone please weigh in on this?
Relocate or remove until complete. Likely need to move/replace water shutoff and meter also unless it comes through wall. If hiring this out, budget replacement and maybe sell the old equipment (Why pay labor to reinstall an 10+ year old water heater/softener/furnace?) Would also be the time to evaluate sewer pipes, perimeter drain tile and sump, and any basement floor drain/toilet hookups.
What's crazy is that house and foundation walls look really new, how could they not have a footing already?
This is an excerpt from the "Midcentury Modern" project which aired in 2019. The home was built in the early 1950's. Much has changed in nearly 70 years of construction since then.
The existing foundation was deemed insufficient to adhere to current building codes, which must be met for additions and full renovations.
They should have vibrated the concrete to ensure it fills the void. Then they need to do the outside as well.
Did this get a city inspection?
Lower expense option to pump? Frugal you say 🤔
Or make a small ramp for the wheelbarrow to run up and dump off the front?
What is the purpose?
tmacfan927 the footing spreads out the foundation loads into the soil. Otherwise, the whole foundation load is concentrated across only the bottom of the wall, which is rather narrow. This can lead to the wall “punching” or cutting into the soil kind of like a knife, thus resulting in settlement and/or failure of the foundation. When I give foundation specifications to contractors and builders, I usually specify a minimum width of 16 or 18 inches for that type of footer (in typical Florida soils).
We’re your shirts buy one get one?
My friend had an addition to his house put a full basement underneath it all pick and shovel World corn elevator 105 buckets of dirt and it was Mason dump go to work we did it came out beautiful retired Union Mason of 100 and a lot of buildings St Anne's Monastery of the Moorestown retirement home for nuns God underpinning there keep your head clear and do your job
I want to know why there wasn't a footing in the 1st place...
A shoddy construction by Joe Shmoe Inc.
What about how to pour a footing on a pire and beam
Kevin f'd off and left them to it. 😂
as always
I don't understand... why did they only underpin a few inches instead of completely underpinning the full foundation?
Probably because it costs more if assume. Theyre doing essentiall a bench footing to keep the soil from underneath the existing footing from moving since that is whats keeping the foundation up. In even older houses like late 1800s to early 1900s they have stone foundations which were actually 2 seperate stone walls which were essentially filled up with dirt hence why century home foundation walls are often around 18 inches thick. The dirt in the middle can actually be disturbed if doing a full underpin because that soil will be disyurbed between the stone walls. This looks like cinder block but just giving an example of where this method could be useful
I'm sure the window of opportunity was tight, but wouldn't completely undermining the foundation walls section by section (enough so that it doesn't completely fall over of course), and using the 1:2 footing ratio be better? I've worked res. and comm. concrete for years, this just seems like somewhat of a bandaid? However, I'm certain since it's TOH, that there is an engineer involved, which is definitely above my payscale...
Yes. The detail they used to retrofit this footing seems very flawed. It's hard to know for sure how bad it is without seeing exactly what they did, but as much work as what they did was it would have been so much more effective to excavate under the walls and do it right. I also didn't see them vibrating the concrete, which would make me supremely worried about the integrity of the concrete under the walls. It's probably fine, but if I went through this much trouble, I would want bulletproof not fine.
Why not pump the material
Maybe because for just a few wheelbarrows of concrete it wasn't worth it.
how do you know if a house had no footing????
@India Marshall like above ground??
No cost discussion makes this less than helpful.
It is different from State to State and municipality to municipality. For example cost will be drastically different between city of a Sacramento and city of San-Francisco.
Igor Kharitonoff of course, everyone knows that. It doesn’t prevent an intelligent discussion about cost.
Underpinning as they call it here is very expensive. Hard to say how much this cost but it ain't cheap.
i'm surprised that is sufficient footing for what looks like play sand.
Funny comment. If you listen to the end of the video the gc says he was nervous not to find a footing on this house which is why they proceeded with this work. I don't believe any engineer was consulted on this job, it might very well have been a house on piles (12 inch walls, no footings..)
Edit: Relooking at the video this looks like a medium compacted sand. Not that bad.
@@EarendilTheBlessed funny comment, lack of reading comprehension
@@davidriley7659?
Just found out my family roomed had no footings after a car drove through it... Turns out Those crazys s.o.b.s.. Turned a garage into a family room and they let it fly back then
a 2 1/2 minute video on how to underpin a foundation.. This is more like "Underpinning, Explained"
House didn't look old enough to not have a footer.
OK, but you must vibrate the concrete so that there are no bubbles, without vibrating it does not meet its strength.¡¡¡¡
I would say so, but I think he is the master mason, and that concrete looks really wet and it's not that deep, so it seems there's actually no need for that.
@@fadetounforgiven And actually, the danger with vibrating concrete is that you can actually vibrate it too much - especially when pouring with the slump they used. Basically, you'd vibrate all of the aggregate to the bottom of the pour, eliminating any strength gained from an evenly dispersed mix, making it actually weaker than if you had left it alone. And as for "bubbles", I'm assuming Carlos Cabezas means honeycomb, which means actual voids in the mix - not air pockets. Concrete needs air entrainment (very tiny air bubbles) for strength and code - except for in rare occasions like interior floors where allowed by code.
@@fadetounforgiven It seems that it is not so good mason, because it is basic to vibrate especially in foundations, which also roughing to fill...
Smartassing rampage in this thread
With that huge nose, turn off hahahaha. She can fly with the broom hahahahaha.
I work concrete for 23 years still going I never got dirty like him
Work harder
The first thing I look for in a concrete & masonry contractor is how clean their clothes are.
...
(Not)
I see only safest of foot wear on the expert. Lol . Then to get that dirty at the end. Lol. Seems to be made for tv.
I am no rocket scientist , but schouldnt the footing go FIRST!
Underpinning only comes into play for a retrofit or basement lowering... So, it's always after-the-fact.
Def not the best way to do this. Poor execution too. They didn’t use a vibrator which makes sure there is no voids! Better off digging out 4ft sections and completely repairing a new footer and stem wall directly under the exterior or load bearing wall.
Oh man, how embarrasing, you guys wore the same outfit