Seeking some advice on basement renovation
We recently renovated a small 2 story, single family row house in Brooklyn. Next up is the basement, but from what I’ve learned thus far – just makes me depressed.
The basement is unfinished, thin slab/dirt floor and 6′ ceilings. Now, i initially thought we would dig and proceed with bench footing until I concluded that filing with DOB + drawings and reasonable contractor is going to cost about 100k. Given the interest rates now, it’s really not possible for us to spend this much.
All I really want is to control the dampness a bit more with a basic waterproofing and just 3-4 more inches. I’m 6,3″ and I just want to be able to have some private space to work on music. It’s 33′ x 14.5′.
Is it possible that there’s still some room to dig before hissing the footing and with not creating any danger? Or completely impossible.
Or, is it even possible to dig out just a small section in the middle so that I could put a desk there and stand comfortably?
Basically, is there any scenario in which I can do something without filing and maybe spend no more than 30k? It doesn’t need to be luxurious.
Any suggestions much appreciated.
j.e.c2769
in General Discussion 2 years and 11 months ago
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workisfun | 2 years and 11 months ago
And the right lighting and air circulation can go a long way, in the meantime. I feel for you.
workisfun | 2 years and 11 months ago
Get a great dehumidifier
Lurker | 2 years and 11 months ago
Right, what’s tricky in your circumstance is that to get 4 inches lower you have: 4″ plus 4 more for concrete, plus 4 for gravel and a bit more because it’s not unlikely your floor is uneven front to back, and so you easily need to go 12-16 inches down. Having just 9″ of foundation below current floor seems to make it impossible unless as you mention you can cut in several feet from the walls without fear of disturbing your party walls.?
j.e.c2769 | 2 years and 11 months ago
But all I really want is 4 inches..haha. Just not that simple. I guess it’ll remain a dirt pit unless I come into some money. So envious of my neighbors to the right. They did it with their entire reno and it wasn’t filed. There are no records of it which in some ways is dangerous, but assuming they did it well, they scored as from what I understand. When you have to bring in the DOB and file properly contractor has to charge quite a bit more because it’s a lot more time.
j.e.c2769 | 2 years and 11 months ago
Right, but a quotes that I got with plans would be around 100k with bench footing. It’s hard to get a contractor to give an accurate quote without seeing the plans (understandable). However, an engineer usually wants a fee to come have a look, and then plans are going to be around 7-10k + permits, etc. In other words, difficult to price..
jimhillra | 2 years and 11 months ago
Omelettetron – To be clear about the terminology, underpinning is the process of digging underneath the foundation. That’s VERY expensive. To save costs you want buttressing/benching, NOT underpinning.
andriywww1990 | 2 years and 11 months ago
Omlettron, so thank you for coming on here because i have learned about my situation as well.
Let me comment to your last line: construction costs may never come down. During 08/09 and covid, i got nervous and thought there would be problems. I did drop prices on a couple of jobs at the onset of covid just to bridge a slow couple of months and be sure i had work to pay overhead (insurance, vehicles, rent, internet) but nothing ever got so slow that there was no work and if it got that bad i would be forced out of business (who works to pay overhead?). I am lucky but some people are not. Some people are forced out of business (nothing spectacular, no bankruptcy auction, they just move to other things) and when that happens there may not be enough people to do the available work and as a result demand goes up and prices remain remain steady. Due to the competitive nature of this industry, contractors do not have such a mark up that they can cut their margins and survive. It more like this; we eat or do not eat. If we do not eat, we do something else; its not a matter of switching from porter house to cube steak.
In so far as the interest rates. I remember high interest rates in the late 70’s when i was in high school and for a few years when i got out of high school. I am not sure what to make of the interest rates but i suspect that even though one might think this would create a softening in construction, i suspect at the same time they and inflation will keep prices up and that won’t be to the benefit of contractors or anyone else: this will hurt everyone. And a lot of people will retire and leave the industry creating more demand.
Maybe people who have carried out multiple renovations through multiple boom and bust cycles can correct me if i am wrong or add to what i have said. There is a guy named DIBS on here, he seemsvto understand the business side of all of this, he may have a better idea.
j.e.c2769 | 2 years and 11 months ago
Thanks for the clarification on terminology. I am learning. I’ve had the test pits dug and it doesn’t look promising. I’ve got 9″ to the bottom of the foundation. And it appears our row house has no footing, just a strait brick foundation right on the ground. I have an engineer coming on Tuesday, but I suspect he’ll suggest the full treatment of digging further under the foundation, bench/underpinning, etc. Well, at least I can rest knowing what the situation is. Maybe in the near future construction prices will come down a bit as the free money ends there will be less work.
jimhillra | 2 years and 11 months ago
When you decide to call it that. 😉
Really, it’s just semantics. Even a basement wall may be a foundation. The difference really is when the above-ground wall changes construction type to withstand the lateral forces from the earth around it.
j.e.c2769 | 2 years and 11 months ago
[IMG_1379](//muut.com/u/brownstoner/s3/:brownstoner:Tm1t:img_1379.jpg.jpg) [IMG_1380](//muut.com/u/brownstoner/s3/:brownstoner:z4yR:img_1380.jpg.jpg)
andriywww1990 | 2 years and 11 months ago
Jim, when does a cellar wall become a foundation? I have always been confused about that.
jimhillra | 2 years and 11 months ago
Doors, you can definitely dig down to the footing. Typically, if there is a footing, the cellar slab is sitting right on top of it, so there’s not much to be gained there. If you want to go lower than the footing, I would assume the same guidelines apply, but they may be more intrusive as the width of the footing would already be eating into the floor space. To be honest, we’ve never excavated in buildings with footings, only those with only foundations. That’s not to say we’ve chosen not to do it there, just that we’ve never had a request to do so.
andriywww1990 | 2 years and 11 months ago
Thank you jim. The confusion for me is not the difference between a footing and what we call a foundation and i sometimes call a cellar wall. With the exception of cellar wall, when i speak of those terms, i am not using them loosly or interchangably.
I was hoping we could safely dig down to the footing in a poured concrete foundation. By what you are saying, it seems not because by the time we hit the footing, we could have already compromised the foundstion wall (if even over time). That was what i was trying to speculate.
I was hoping you would weigh in here. Thank you.
For others reading what i was thinking of doing in my reply above, what jim is saying is an engineer must be consulted no matter what with any excavation along the cellar wall.
jimhillra | 2 years and 11 months ago
It sounds like there’s some confusion over terminology. There’s a difference between footing and foundation. The foundation is the walls you see when in the cellar (also different from a basement). The footing is at the bottom of the foundation and is usually significantly wider than the foundation. It spreads the load from the foundation over a wider amount of earth so the foundation doesn’t cut through the earth like a knife.
In older houses, the foundations were stone (large pieces mortared in place), and did not have footings. These are called rubble foundations. Some foundations went well below the depth of the slab/floor for any number of reasons. In these cases, you can dig down to a couple of inches above the bottom of the foundation, and pour a new slab there, as long as that slab locks in the foundations so they don’t slip inward over time.
When exceeding the depth of the foundation, an engineer usually suggests a formula of between 1 to 1 and 1 to 2, depending upon the quality of the soil. That means in good soil, every foot dug down requires on e foot of horizontal buttressing, or benching. In worse soil you may need as much as two feet horizontal for every foot vertical.
Maybe this will help give an idea of how much room you’d have left within the buttressing after digging down a foot or so.
andriywww1990 | 2 years and 11 months ago
ok, as much as i like to come on here and tell people what i know, i have to admit when i do not know something: i am not a structural contractor. that does not mean that i have not dug footings and have not been on jobs where a foundation is being poured, but i have to ask people about this stuff just as much as any homeowner on here. hence, why i call restoration bill of laredo construction.
i did bring bill here and we i told him what i originally wanted to do, which might have been a gain of like 10″, he mentioned a bench footing and that was it, i did not want to hear anymore. same thing that happen to you.
so i thought about how far down i really had to go to give me enough height to put a girder in. i need 4″. i do not know if i can safely remove 8″ of rat slab and earth from here without compromising the cellar walls/footings and really, i am not inclined to ask anyone (sounds stupid right? this is where people get in trouble). this is my plan: around the perimeter of my cellar, i will dig out one 5×5’x8″ section (maybe make it a 4×4″x8″ sec tion), possibly making it a little deeper at the edge along the wall – like a curb on a road -and maybe add some rebar to that curb and fill it all with concrete. give it a few days and when that section has cured, go move to another 4×4 section. and so on and so on. once i have the perimeter done and stabilized by this system of slabs and curbs, then i move to the middle and dig it out to 8″ and pour 4″ of concrete. when this is all said and done, we have 4″ of concrete (which is the thickness of a sidewalk) plus the addition of a curb, all butted up against the cellar walls. will it matter that it is 4″ lower? i do not know.
this is only what i am thinking. it will be interesting to see what others say.
i would not even consider something like this with a stone wall. but, if you have someone with a lot of talent you can ask or if you bring an engineer back in, maybe you can consider is what luker is saying. if an engineer told me i could do something like this, i would probably tell him to draw it and make him put his stamp on it and i would then follow that drawing to the t.
does anyone on here know how safely someone can dig to the bottom of a footing? and how wide they can dig along a footing? that is the question and different soils & different materials = different conditions.
j.e.c2769 | 2 years and 11 months ago
Man you got lucky. I think I’ve honed in on someone to come out next week and dig some test pits. I guess I’ll know then.
Lurker | 2 years and 11 months ago
Our test pits at the walls showed the foundation kept going far below where we dug down and so it was safe to build without putting in bench footing. Also our front and exterior foundation walls were 18-20″ thick.
j.e.c2769 | 2 years and 11 months ago
Correct, I’m trying to see if there is any legal, safe way to gain 4 inches. I do not need a legal, livable space. @doorsby – I actually do not know what the footing is. I was hoping to find someone experienced to do some sort of probe. I did have an engineer come out and take a look, but he was sort of in and out, then proposed digging down 2ft and installing bench footing. I was fine with that until I realized how expensive it was going to be and getting a good rate on a loan these days is out of the question. Thus, I’d be happy to just gain 4 inches if there’s any way to do it. I’m thinking my foundation must be stone because it’s more than 100 years old and I do not think they were pouring concrete back then. The slab that’s on the floor currently is basically an inch or less of poured concrete that’s so thin it’s dirt on one half. I guess I need to figure out how much deeper the wall goes to the foundation. If I’m at the bottom already, then I don’t think there’s anything I can do except bench/underpin. However, if the wall/foundation goes down quite a bit more, th en I’m assuming you can dig out the dirt completely level with the foundation. Going any further than that would threaten the structural integrity.
andriywww1990 | 2 years and 11 months ago
There is a guy who used to be on here. Restoration Contractor. His name is bill from laredo construction. I consulted him about this for my own house.