My sister has what appears to be a failed footing drain and asked me to repair it. I’m not sure what I’ll find when I excavate since this place was built in the 70’s. I’ve done some research and have a fairly good idea what I need to do for replacement. Here’s what I have in mind and feel free to correct any errors.
I’ll place 2-3″ of 3/4″ stone at the bottom of the trench. I’m thinking the trench should be about 20″ wide. Then 4″ pipe covered by another 2-3″ of stone. The top of the drain pipe will be level with the top of the footer. I’ll cover the pipe with a pipe sock along with a similar fabric on top of the last layer of stone before backfill. I’m still not sure which drain pipe is better though, the white ABS with holes in the lower section or the black with slots all the way around, or does it matter?
What I’m most concerned about is supporting the 6′ trench walls while the work is in progress. About 30′ will have to be dug by hand since there is no room to get a machine in there and I don’t want to chance damaging the basement wall. The remaining 100′ or so to reach a daylight exit will be dug with a backhoe. Do I need to shore up the trench walls or is 6′ shallow enough to support itself?
Thank you
Replies
What type of soil are you dealing with?
Here in NW Oh we have expansive clay. A hole might not collapse for years. In Cleveland, on the other side of the state they also have clay among others. I know a guy that got collapsed on running sewer line-down a little more than 4-5'. #### ed him up pretty good-long recuperation, he's fine now.
In our clay soil I backfilled all the way up with stone. If the clay shrinks during dry weather it leaves a pocket against the foundation. More than one basement has been pushed in by freezing water in that space. If you don't want stone on the top, lay some filter fabric b/4 you add a foot or so of soil to grade.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
I'm not 100% sure but I think a couple feet of clay then sandy gravel followed by hardpan. I was told this by a neighbor. I'll have to dig a test hole to be certain.
Alright, where are you located? There might be a neighbor here on BT. Filling in the profile or mentioning pertinent info in the post such as location can help make these answers a little more to the point.
You can also contact your local extension service and/or ask a local excavator.
Best of luck.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
I'm in Westerly RI near the CT line. I didn't have much luck with the local extension folks when I was seeking info on a potential property purchase. I'll see if I can find an excavator to ask.
thank you
Where do I fill in this profile you mention?
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Over there up top on the right below the Masthead is this ^ line. Click on My Forums and then on the left of that page that comes up is My Profile (or something like that). Click on that and fill it out.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Edited 2/16/2008 10:33 am ET by calvin
Or just click on your own user name anywhere you see it underlined (linked) on the page - like at the top of this message.
I found it
Thanks
in westerly, don't you have sandy soil ?
i wouldn't trust an unshored trench in that soil any deeper than say 3'
you may be able to make yourself a trench box for your hand excavationMike Smith Rhode Island : Design / Build / Repair / Restore
Yes sandy gravel is common. But I've been told this small development was filled in with a few feet of clay(?) to level out the site. Talk is cheap so I'll know for sure this coming weekend, weather permitting.
Edited 2/18/2008 8:47 pm ET by JSan
Is it at all possible to get a mini excavator in for the house dig? it could also be used for the trenching.
They rent some mighty small machines, some with linkage that allows you to get close and parallel to the foundation.
Even if you excavate an oversize trench at the foundation, you will probably not have any real increase in cost by the time your time and material for shoring is purchased.
Terry
I'd be a little nervous digging that close to the foundation with a machine. I do have some equipment experience, but not enough to chance it. I thought of getting one of those small tera-mite rigs and work 6-8" away from the wall for the bulk work. I'll still have some hand work because of a deck and shed next to the house.
Woonsocket, R.I., Trench Death Leads to $89,000 in Fines for Warwick
Contractor's Failure to Supply Cave-In Protection
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=NEWS_RELEASES&p_id=10352This trench was deeper, but in disturbed earth with excavated material placed near the lip a failure can easily happen. Google trench collapse and you will get a lot of news items that include "fatalities." Get advice based on your soil conditions and the job can be done safely. Good luck.
I rented a tera-mite once. And it was a POS. Now probly mostly because of maintance. And I was only using the front bucket to carry rock and backfill.But I did the digging with a mini excevator and it was so much more maverable and controlable.And the have compact loaders with back hoes that can get into real tight spaces.A compactor loader is "toy" bobcat like machine that walk behind or stand up and ride.Here is one style.http://www.toro.com/professional/sws/loader/
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I was thinking about something like this next to the foundation wall. Is it a POS? Access is limited, so I don't think much bigger would work. In fact even this will be on the tight side. Still has to be better than doing the whole 30' by hand. For the 100' run, I have a 580 case to use.
View Image
Edited 2/17/2008 12:44 am ET by JSan
That looks similar, but a little different from the one that I had.Most of what was a a POS was the maintance. Rusty gas tank, screw driver to operate the ignition, the arm on the backhole kept leaking down.But it also had some design problems for what I was trying to do with it.I was only useing the buck and needed to move wet dirt around. And when I got the bucket down to where it would dig into the dirt it lift the front end and I had no steering.But for the digging the small mini-excavtors will get into tighter places.I think that I one that I rented was about this size.http://tinyurl.com/39ltjathe track base would set in the Ranch PU bed..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
That mini track hoe looks slick! No outriggers would be a plus. Looks like the hoe has a further reach than what the tera-mite, which would be ideal for the limited access. I'll have to see if United Rental has one.
That won't dig a 6' trench unless the soil is very soft and is pretty much devoid of rocks and roots. I've rented those before and they just aren't strong enough - maintenance or no.
Maybe the drain tail is just crushed or covered up and you can replace/repair that section using the Case machine. Be careful with that (or any heavy equipment) though. It can mess a house up in a heartbeat... Don't ask me how I know.... The reach of that boom will get pretty far up from the corner of the house though.
Regarding the digging in the tight section, take a look at the attached pic. (right click on it and choose "open in new window"). One of the reasons that these machines are so versatile is that they can dig along or slightly beyond the track line, as opposed to being limited to (more or less) right down the middle of the machine like with a standard back hoe. The picture doesn't show it that well put if you look closely you will see that it looks like he is dogging down his track line. You could probably get away with a slightly smaller machine than is in the pic.
If there is not access to get that in there you need to invest in some shovels and rent some "shovel operators".
The little track-hoe that Matt shows is the way to go. I've used one a couple of times for just the purpose you explain in the OP. Since the boom swivels as well as the cab, you can swing the boom to the side and then swivel the cab to set the boom parallel to the house. Can't do that with the front end loader/hoe combo.
For the areas out of reach of the boom (under deck etc.) you can set the bucket at the bottom of the trench and hand shovel into it. * or shovel it close enogh to grab withthe hoe*. The soil around the house you'll be digging will have been backfilled from the initial build so probably not compacted and be easy digging (relatively speaking).
No suggestions for shoring the trench but a significant factor you must consider.
edit to add text between *_*
Edited 2/17/2008 10:30 am ET by john7g
"Since the boom swivels as well as the cab, you can swing the boom to the side and then swivel the cab to set the boom parallel to the house. "The little one that I had didn't do that. Neat trick.About the digging power, I did not have to go down that deep. The deepest was about 36" and most of it was 24".And I had a relatively small bucket on my. 8" IIRC.But I was able to pickout a couple of 150 lb rocks.And I was surprised at it's reach. I said at the bottom of a small "hill" and treched up it about 10 ft..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Max depth I've had to dig was 9ft. Max hand dig was under a covered porch, 9ft depth for a run of 8ft and turn the corner for another 15' or so. Can't remember bucket width... maybe 10". Dug trench 20" to 30" in width to allow reasonable work space for drain tiling and sealing the block walls.
Fortunately the clay here is somewhat stable but I still piled the dirt far enough away to reduce it's impact on the trench but not so far that a lot would get lost when backfilling.
We always wrap the entire gravel section with filter fabric like a big burrito. The idea is to keep the drain field clean, contaminants move sideways as well as down. We use SDR 35, which may be what you call the white pipe. The black stuff in coils is inferior. Pipe should pitch to drain. Put a clean out at the high end and any other area ripe for clogging. Those are typical soil engineer details.John
What about a pipe sock in addition to wrapping the whole shebang with fabric? I recently read soemthing that says not to use it as it can clog with silt and shorten the lifespan of the drain. Better to rely on a clean out if the pipe fills with silt. Any comment?
So the black pipe is junk? Thanks, Good to know. I never used it but thought it might simplify the installation if I run the trench at an angle from the house corner. Fittings and straight lengths it will be.
can I come over and play? ;)
Ductape can fix EVERYTHING!!!
Edited 2/18/2008 2:56 am ET by andyfew322
United Rental said the same as you did about the teramite, so I'll rent the mini trackhoe instead. You saying that these rigs can crab? I'll have to hop on it in the next couple days and try it out. That would make a world of difference if so. The only hand dig would be under the small deck.
No idea where the tail is and no one else does either. What I did was shot a laser from the top of the precast and found a spot 6' lower about 100' away that will exit to daylight in the yard. If I angle the trench over a few feet instead of a straight line I think I can get 8' drop so that should give me enough for the pitch. When I excavate, I hope to see where the existing goes if there is one.
"shovel operators" yeah I hear that. I'm already licensed :)
When you say "crab" I assume you mean moving the machine laterally using the bucket - yea - they do that. Don't think you are going to hop on one and be an expert though - it will be pretty rudimentary for the first several hrs... Maybe your bud could give you a 20 minute course. It would probably help a lot. It's not as easy as it looks.... Really though, I found a mini excavator easier to operate than a teramite - maybe because the latter was so underpowered. The min-x I played with at work was a cat. Pretty nice. I used another one for several hrs at my house but it's been a while and I can't remember the brand. I think there are 2 basic different types of controls - one is opposite of the other - I forget what they call 'em.
One final word. Keep in mind that these drains don't have to have much pitch. Water will run to the path of least resistance so just so you make sure the pipe doesn't run up hill, you will be good. Pipe with too much pitch can clog - although it has to be kind of extreme. Really you are gonna have your hands very full just trying to dig a ditch with a relatively flat bottom on it. You said something about a laser, so that will help a lot.
Yeah that's what I meant.
Are they that difficult to operate? Doesn't appear so to me. My only weakness would be speed and overly cautious about wacking the house, shed or deck.
You mention excessive pitch. Is 1/4" per foot too much for this application? That 100' run equates to about a 2' over that distance
It takes a little time to learn how to operate a hoe... It's easy to just dig a hole but to me the hardest part is learning how to draw the bucket along the bottom of the trench making it somewhat uniform. Also, a good operator can see what is level from up on the machine - it's an acquired skill - but still most use a helper with a rotating laser and a rod when doing longer runs of pipe or footers. My plumbers do shorter runs of pipe with only a level. When they think they are close, they throw a piece of pipe down in there and put their little plumbers level on it. If you were using flex pipe you could use just a fairly straight 2x4.
Regarding the pitch, just as a general concept, 1/4" or 1/2" a foot is fine. 3 or 4" a foot would be too much. Hopefully there won't be much of anything in there other than water anyway so it probably isn't that critical. Did you decide to use rigid or flex pipe?
Using the hoe isn't a problem for me other than when the pins are sloppy. It's a pain trying to control it when it swings around like a limp noodle. My buds Case isn't bad, but bad enough that I'd worry about smacking the building on the return swing. It won't fit behind the house anyway.
I agree with the acquired skill. Eye and hand coordination is the key. I'll be fine roughing the trench, but to fine tune it, I'll set a string line with a laser and work from that. I've had great results doing it that way when working alone.
I'll stick with the rigid pipe, it's all I've ever used. Thanks for confirming the pitch, I wasn't sure if footing drains were pitched differently than curtain drains.
The Terra-Mite is a poor substitute for a real machine. They are under powered, poorly designed, and don't allow any production. I used one once, and NEVER again. For a few bucks more, go for a tracked mini-excavator. That's the machine you want for this project. It is more maneuverable, more powerful, and easier to operate.
and work 6-8" away from the wall for the bulk work.
Moving that bulk will be worth while.
If you are not confident with your operator skills, hire that part out. Time and money well spent. You will have plenty to do with tile installation and backfill.
Terry
I second the mini-excavator suggestion. Here, 10 years ago trench excavation was 95% by backhoe. Now it has flip-flopped to where trench excavation is about 75% mini excavator. The fact that they rotate on their track base as well as hinge at the boom is what makes them so versitile for tight situations. Don't get too small a one though as it won't be up to the task.
That and some labors - ¿usted entiende?
6' is a pretty respectable trench. When I read about accidents involving trench collapses, it's about a 50% or more for a fatality. OSHA requires anything 4' or deeper to be shored or graded back at a 45° angle. I'm not the most safest guy around but this is one thing I don't play with.
Regarding what you are going to do once the trench is opened up, you didn't really say if this is a basement - I assume it is. If so you need to thing about how you are going to waterproof the foundation. Besides a coating or membrane you need to think about a drainage plane.
On second thought, maybe this is a bit over my head --pun intended! I've done curtain drains 3' deep no problem. So I figure what's another 3'
The foundation wall provides a partial suppport, but that 100' stretch has nothing. You guys give me the feeling I might be digging my own grave. What about if I use some plywood and 2x to make my own supports? Something like what I see used when they trench the roads for sewer and water mains? I could make up 2 or 3 sections and move them along as I work. Course the road jobs are made of steel and not wood.
re- waterproofing The basement wall does have some tar like coating on the outside, I can see some of it above grade in places. Should I plan to recoat it? As for the drainage plane, I've seen this stuff on the net but didn't plan on using it. The leak looks like its coming from the base of where the precast concrete steps connect to the exterior of the foundation and also at the corner of the interior wall, about 10' away from there. She has mentioned in the past it leaks during heavy rains aand during the last few winters, it's gotten worse. I'm guessing that with the frozen ground, the water has no place to go, so it weeps down the wall and finds its way in at the bottom, more or less proving the footing drain has failed. Gutter downspout extensions are in place and it has the correct grade pitch. Someone suggested to her that she just cut the floor there for a drain and use a sump pump, which sounds like a bandaid at best.
I'd rather do this once and do it right for her. My sis doesn't have much money, so hiring this out is probably beyond her means. On the other hand, I sure don't want to lose my life over it. I think the next step will be to get my bud's 580 case over there and dig down to see what the soil composition is. With the warm-cold temp swings lately, I don't believe I'll have much problem digging.
Thanks for the info guys.
Hey, I don't do houses for a living or anything, but I deal with some industrial construction for work. And I'd take the concerns about trenching that deep unsupported pretty seriously.
I think digging outside is preferable to letting the water in and then catching it, but that may not be practical or the best course of action. If you do dig, I have a drainage plane recommendation- Delta MS. I had to dig up the foundation on our addition to fix the drainage and waterproofing. I found a remnant via the local vendor (since I only needed a couple feet).
It was relatively simple to put on and seemed the best choice for a dirty, freshly-excavated block wall. I did the membrane and made sure that my footing had gravel over the top to get drainage from the wall to the drain line (below the t/footing). And all the gravel was wrapped in fabric.
We only have about a foot of drop between our footing and the street, and this seems to have taken care of all our problems related to water in the crawlspace.
I absolutely agree with not trenching inside. It may work when all else fails, but in this case I'm certain I'll be fine with staying outside sans the digging
I googled the Delta MS product. Looks promising. But if I only have a small leak at the base of the wall, does that justify the expense? I'm sure it's not cheap.
Would it be a mistake if I just left the wall alone? I know I can minimize any damage to the existing coating by only using a shovel within 6" of it. I'd sure hate to go through all this work and find I created another leak by skimping.
I have a suggestion that is what I would do. I would start at the corners of the building on the downhill side and find the existing pipe. Open it up and see if has flow or does it have standing water. Your problem could be a pipe that has been plugged away from the foundation or that never adequately reached daylighting. Might just be that digging up the whole layout isn't needed.
They can't get your Goat if you don't tell them where it is hidden.
Good idea, I'll do that. Thanks
Might actually do both corners of the building (or whatever it has.) Some projects have two or three outlets rather than have a loop around the house all tied into one outlet. If it isn't flowing I would dig the trench you proposed earlier to day light and see what happens. Hard pipe the new trench (non-perf) and put a clean out in near the house.
They can't get your Goat if you don't tell them where it is hidden.
Dig both even if the leak is only at one end? I could do that too, but I'm more curious to attack the problem end and see what's there. As you said, if there's standing water there, then maybe I won't have to dig next to the house. Just try and follow where this goes and make sure it goes to daylight.
You'll have to ask the pros about whether you can dig it without compromising the existing coating. I'd be suspect, though. With ours, I'm not sure where all the leakage was coming from- somewhere up on the wall or at the base. The main thing was to make it easier for that water to get out to the footing drain than into the crawlspace.
I'd track down a local vendor to get an idea of cost- I spent $40 on a remnant (and used about 10% of it). You'll need the membrane, a mess of the plastic washers for nailing into the wall, termination strips, and a lot of masonry nails.
My conservative guess is that you'd spend ~$300 for all the parts. Don't know where that falls on your expense scale. But I can't imagine digging the whole thing up without doing whatever it takes to never have to do that again.
And maybe someone has an alternative membrane suggestion.
I didn't realize that the membrane was mech fastened to the wall. I don't think that's something I want to be doing. I thought some type of mastic or tar was used to hold it in place until backfilled.
I'll have to see what the local water proofing guys do or use.
Really, I wouldn't be so quick to discount it. I looked- I'm pretty sure there's a FH article that talks about this specific product, but I can't find it. It would've been in the past 4-5 years.
I think the issue is that it's unlikely you can do good enough surface prep for a liquid membrane to last in a retrofit. That and it'd be a lot of work. With that kind of height, I don't think there's anything you could rely on tar to hold up until you backfill.
With Delta MS, the washers that you nail on to hold the membrane to the wall have a little cup that the nail sits in. If you're fussy (I was), you can tar over the heads of the nails to protect them. The mfr. instructions don't seem to say you have to do that, though they do want you to overlap and tar between membrane joints.
The point is that the dimpled membrane creates an air gap at the foundation wall. Any water that gets through it (via nail holes, over the top, or whatever) just drains down. Then you provide a way for it to get into your pipe drain at the base of the footing. And you're good to go.
Here are a couple of Breaktime topics that discuss the product: 12338.1, 60901.5, 56508.1, and 69822.29
I'll look at those threads later today, thanks.
The reason I am hesitant to shoot any nails is because there have been a few times when I shot nails in concrete, it would knock chunks out of the wall and the nail still wasn't fully seated. It didn't hit any rebar, so I figured operator error or bad concrete.
I agree with you about not putting nails where you don't have to. The hole not made never leaks!I have seen membranes that use a primer type coating, add the membrane, and tar over again. Some have a terminating strip at the top that is mechanically fastened, but those are the only holes. The strip acts kinda like flashing, to keep water from running down the wall behind the membrane.
Not all membranes are mechanically fastened. W.R. Grace Bituthene (sp?) 3000 I believe is a peel and stick that uses a primer. Walls must be clean and dry , (prime is optional I think ) , peel and stick . http://www.na.graceconstruction.com/product.cfm?mode=c&id=137&did=11 There are others out there as well. Google up foundation water proofing membranes and start a search .
They can't get your Goat if you don't tell them where it is hidden.
I didn't know Grace made a product for below grade. I'll hunt some down.
Thanks for the info!! I can't get over all the great tips and advise you guys have to offer.
We use that stuff around here too for basements. A little spendy...
There are a number of companies that make water proof sub-grade material for this application. Shop around online a bit. "Big Pink" also has something .
They can't get your Goat if you don't tell them where it is hidden.
How do I find those topics MrSludge listed? When I C-P any of the numbers in the search box, it brings me to the post he listed them in in this discussion
Beats me, I can't get it to work either. Play around with the advanced search using basement waterproofing, or foundation water proofing. See what you hit on. Just google Foundation water proofing products as well..
They can't get your Goat if you don't tell them where it is hidden.
Go to the Advaced Search at the top. It is easier if you open it in a new tab or window.Then at the BOTTOM is a place to put in a message number and separate search number.Or you can open any message in a new window or tab by right clicking on it.Then replace the message number in the URL with the one that you want.Orhttp://forums.taunton.com/n/main.asp?webtag=tp-breaktime&msg=60901.5This is one. After reading it, replace the message number with another one..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I hadn't seen the advanced search before nor the thread number in the current url. Tried it both ways and worked just as you said.
Thanks for the help Bill
I also found the answer in one of those threads to another question I was going to ask. Can I just dig down half the distance instead of the full 6'. Piffin answered that one.
Silly question Jsan, but why curtain drain?
If home was built in 70's, probably block.
If it is block, I would personally rather go inside and put an interior drain in along the foundation, punch drain holes in the bottoms of the block at the cores so they drain into the drain, and then run over to the corner and either put in a sump pump or, preferrably, dig under the footing and run to daylight. (No matter how windy, or stormy, the gravity never goes out)
Of course, you need jackhammer, and are going inside to do the work, but you are already planning to have laborers. They can do all the work and about 20 drywall buckets later, you are ready to patch the floor.
Just food for thought
Jeff in PA
No block, thank god!, it's poured concrete. I don't like sump pumps and I don't feel comfortable disturbing anything under the footings. No bad experiences, just my opinion based on what I've heard and read.
What's wierd is there was some heavy rain today and it didn't leak a drop. Maybe the 45 F temps had someting to do with it? I know it leaks because I've seen the aftermath from storms in the past. My sis says it's been getting worse and doesn't want to end up with a flooded basement like soem of the neighbors have now.
For pipes I think the smooth pvc stuff with the bell ends is better than flex. I think you can keep the slope better with the rigid pipe, plus you don't have the corregations to collect water and possibly freeze.
I would imagine that 6' trench does require shoring. Even if code (or OHSHA) doesn't require it, shoring will be a good idea. Confined space accidents are one of the leading causes of death on construction sites.