Update: Water in my crawlspace – new contract
Hello everyone, Here is some new info about what happened today. The builder/architect came with three guys who did the footing drain. I was expecting from them to make exploratory holes down into the ground where the footing drain is situated. One of the guys who was mainly responsible for the footing drain made a hole about 2 feet paralel with the footing drain to see if we have standing water. I told him that I was expecting to check how the drain is installed, if it’s broken, if it’s clogged. He started to scream at me saying that he is not going to do that as he is digging would affect the drain, the gravel and the fabric – the footing drain would colaps where he would do the digging. I didn’t understand what he was saying. I told him that are many people who do exploratory holes to check the footing drain and after they cover it back if the footing drain is properly installed. He told me that he installed the drain along the footing and not on top of the footing, he pot fabric around the gravel, but he didn’t coat the foundation – the wall and the footing. It was a very unpleasant experience. They dug a different hole to see if we have standing water. About 3 – 4 feet in the ground. No standing water. I told them that is not relevant if the drain works or not. They didn’t listen what I was talking. They concluded that water comes from underneath the slab. In the end they are going to install hidraulic cement in the gap around the slab as the slab is not connected to the footing or to the wall. I told them that I will give them the chance to fix it in their way, but I don’t believe that the hydraulic cement is going to work. What are your thoughts about this? Thank you
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
I think it's possible that a sump plus pump will work to remove rising ground water (from underneath the slab).
I agree. Either a sump or an internal run of rock and drain-pipe. Trying to use the slab as a lid on groundwater won't work.
Could you please give me a professional answer why the slab can't be use as a lid on ground water? I feel the same, but I don't have the vocabulary or knowledge to prove it.
Ground water is under pressure. You get rid of it by providing something that relieves the pressure and allows it to be removed. That's what sumps do and what perimeter (or interior) drains do. Trying to stop it by putting a lid on it (by sealing the slab) doesn't deal with the problem of relieving the pressure.
Thank you. It makes sense to me.
You need to drain away the groundwater. If you try to make a “lid” the water will find every tiny gap and crack and percolate up and get in. You can’t really build a backwards pool in this case to keep water out.
Even tiny amounts of pressure when distributed over the entire area of the slab will result in massive forces to deal with. The drainage system relieves this pressure and drains the water away.
Bill
Water should find and fill the lowest void first. If your drains were the lower than your floor the drains would be full of water and your crawl space would be dry.
In my opinion he has zero chance of sealing 100 feet around perimeter watertight. It is best practice is to make control joints in large slabs. Large slabs are bound to crack somewhere, the control joints are weak spots so when it cracks it is expected to crack in the joints and not elsewhere. How will he make the control joints waterproof? If he pulls off this miracle will he come back should it leak again in 6 months or 3 years?
Could you get them to tell you how much gravel if any is under the slab.
Walt
Hello Walt,
He didn't put any gravel under the slab. The crawlspace is about 400 - 500 square feet. No control joints. He mentioned yesterday that the slab is about 6 to 10 inches thick.
Without gravel to allow horizontal flow under the slab, I wouldn't expect a simple sump/pump to work. It would require a new floor above the current one.
It is possible to build concrete cisterns than don't leak. But crawlspaces/basements aren't designed like that.
Yeah. Unless you got really lucky and situated the sump exactly where the worst of the infiltration was coming from. When we excavate and find water seeping from the bottom of the hole, we run lines of perforated pipe at six ft oc, and cover them with drain rock before adding fill below the slab.
Jon, why would you need a new floor?
To create a drainage channel between the old floor and the new floor. A drainage channel (eg, dimple mat) allows water to move from where it enters to the sump.
The area is small and unfinished. It's possible that a second floor and a sump is your best solution. You could forget about all the exterior drain details.
It doesn't make sense to me why he saying the if he would dig up exploratory holes above the footing drain, the footing drain would collapse. Could someone please help me understand that?
Weight of digging equipment could cause damage, and there is a risk of hitting the drain while digging. Hand digging would have little risk, aside from possibly piercing the drain line with a shovel (which could be repaired).
10” thick for a footing makes sense, but not for a basement slab. Slabs are usually around 4” thick. Even if the slab and footing were one pour, standard practice is to make the footings thicker than the slab portion to save on concrete. Even commercial buildings rarely go thicker than maybe 6”. To put that in perspective, major roadway surfaces are typically 8” thick.
Without any gravel under the slab it’s going to be difficult to deal with the wetness. Gravel under the slab would normally help to drain away water from the underside of the slab.
Bill
Poliana,
You shouldn't start multiple Q&A threads on the same topic. This is the fifth thread you've created about a single problem. The correct way to proceed is to post all comments on the original thread. That way, GBA readers (and editors) can check back on the details of your problem without searching for links to other (apparently abandoned) threads.
These are the multiple threads you have started on this topic:
Nov. 17: Water in my crawlsapce
Nov. 28: Footing drain pipes
Nov. 28: Sump pump installation cost
Dec. 4: Footing drain
Dec. 7: Update water in my crawlspace
Ok. Thank you for letting me know.
Martin,
What your thoughts about my update!
Poliana,
I agree with Walter that it's highly unusual for a crawl space slab to be 6 to 10 inches thick. Two to 4 inches is the usual range.
We are all hampered in our analysis by the fact that we are only getting information from one party in this dispute. But a majority of commenters have pointed out, for several weeks, that the most likely cause of your problem is that the footing drain was installed too high. If there is no crushed stone under your slab, that would be a possible second error.
If I were investigating this problem, I would dig a hole that allowed me to check the height of the footing drain with respect to the footing.
I call BS on 10 inch thick slab in a crawlspace. That would be 5 times thicker than normal rat slab that is generally installed in crawlspaces. The footers would be about 10 inches thick. Now I wonder if he poured the slab and the footers together so the top of the footing is the top of the slab. That would explain both the 10inch thick and the lack of rock.
Digging close to the house is risky in that you could hit the house with the equipment. If little rock was put over the drain the operator could damage the drain before he saw the rock.
Walta
Thank you so much for your efforts!
The architect/builder told me on Friday that he didn't put gravel under the slab and that he had a lot of concrete leftover from the living room slab. It wasn't planned to have 6 - 10 inches for the rat slab.
I understand that you could damage the pipe via excavator, but the footing drain guy told me that the footing drain is going to collapse from underneath. I really don't understand anything what he is saying as I think digging by hand wouldn't do any harm to the footing drain. Maybe something minor, but I am sure that this could be fixed.
To make a 400 square foot slab 2 1/8 inches thick requires 7 concrete truck loads of 10 yards each. 10 inches thick is 33 truck loads. He over order 26 truck loads and could not cancel? Total BS! A full truck would change the slabs thickness less than ½ an inch.
Today no one digs a hole with a shovel more than a couple of feet deep, the labor costs would be too high. If you want it dug by hand the shovel will be in your hands.
How deep is your basement?
Also the sewer video normally has a depth number on the screen but it may not be very accurate.
Walta
Walter,
400 sf of crawlspace = 44 yards. At 3" thick that = little over 3.5 cu yards of concrete. Not great measuring for sure, but nothing like what your math gives.
Malcolm you are correct I mistakenly read the cubic foot number as cubic yards.
It still looks like he was off by a full concrete truck.
Walta
He was off by a lot more than any builder should be. I wonder how he got it that wrong? Years ago I send back almost a meter of mix, and the guys at the batch-plant still bug me about it.
I am going to find out the exact square f of the crawlspace and other details.
Please correct me if I am making mistakes. I just used a calculator to find out how much concrete you need for 6 inches thick , 400 square feet concrete slab. It says that you need about 7 cubic yards of concrete. A concrete truck is about 8 cubic yards.
https://www.calculator.net/concrete-calculator.html?slablength=30&slablengthunit=foot&slabwidth=13&slabwidthunit=foot&slabthick=6&slabthickunit=inch&slabquantity=1+&slabcal=Calculate
Yes around 7 yards. While this is amusing, it doesn't have much to do with your problem - except that cutting a hole for a sump and rock would be a lot more involved than if there was just a 2" scratch-coat.
Here is a photo with the sprayed foam insulation before concrete slab was installed. I just asked the architect if he installed gravel underneath the insulation in my living room which has a concrete slab. We ended up installing a wood floor in the living room, because the concrete was very cold. No radiant heat.
Hello everyone,
I need your help. The builder/architect hired a civil engineer which I think is a good step. The architect was asked to make different holes in the foam that is installed on the wall. The walls underneath the foam are very wet. I tried to post a photo here, but it doesn't work. Here is a link with photos and videos. https://photos.app.goo.gl/4mE2uq6c8msThr2U6
We don't know why the walls are so wet. What is your opinion? Please share your thoughts.
GOod morning! The builder/architect hired a group of civil engineers. Please see the remediation work that they are proposing:
https://photos.app.goo.gl/1T29Woh95UFftNbq5
Poliana,
The key sentence is this one: "The existing footing drains will be inspected and if they are found to be installed on top of the footings they will be moved to along side the footing."
That's the remedy that several of us recommended to you, many weeks ago.
Looking back at one of your previous threads, I noticed that this is the advice I posted on November 18, 2018: "If the footing drains are below the height of the top of the slab -- and they should be -- then water will drain out of your footing drains before rising high enough to enter your house. In light of what's happening, it's clear that something is wrong with the footing drains. They may be crushed, or they may have been installed too high (above the level of the top of the slab)."
Sounds like a great plan.
Who is paying?
To me that sounds like ever bit $10K.
I forget do you have a low spot for the drain?
Thanks for the update
Walta
From my non-expert vantage point this seems like a very good solution. I'm very happy for you and your family that this is going to happen.
Hello guys! After 5 months of going back and forth, the architect/builder decided to hire 2 civil engineers. The engineers came up with the List. I showed the list to a friend and the cost of this could be around $25,000. Hopefully the architect is going to pay as we are still under warranty. My lawyer said:" Something significantly structural like this is usually several years. Since they have notice of the defect though, it doesn't matter if the warranty period lapses while they are undertaking the repair. - Joe". These 5 months were very hard for me as the architect tried to patch the mistake hiring a few contractors. I had to fight with him till he hired those engineers. What would be the best month to start working on this?
You don't really want to do any significant earthwork while the ground is frozen or saturated. In your area, that probably means after the end of April.
You also want your attorney to check the warranty requirements. They vary in important details state by state. In NJ, water leaking into the crawl would only be covered for one year and it would not be considered a structural defect. Making a claim with the builder would not suffice to keep the coverage in force while they work to fix the problem - you actually have to file a claim with the warranty company itself. Make sure to read the fine print on the policy and to follow the directions to the letter. Otherwise, the builder may be able to just walk away from the project after the first year ends.
What is "warranty company itself"?
Hello everyone,
It looks like the builder/architect change his mind after we agreed, back in February, with the civil engineers etc.
1. He doesn't want a Bilco door anymore
2. He doesn't want to remove the existing slab out and install a new one with a drainage underneath.
3. He wants to change the footing drain only around the crawlspace and not in the area where the house is build on the slab.
Could you please help me here? Does the code say where to install the footing drain? When you have a crawlspace built in conjunction with a slab ( the same house) don't you need a properly installed footing drain installed along the footing?
Please read below the email that was sent by the builder/architect yesterday:
To reiterate what we all know; the footing drains where we are excavating are going to get destroyed and will need to be replaced.
If it is found that the existing footing drain was installed next to the footing then we will be able to tie the new footing drains back into that system that drains to the south (towards the aqueduct). If however it is found that the existing footings were installed above the footing, then we will not be able to tie the new drains into them and will instead create a new drain to daylight off the east side of the house (towards the back).
I would like to correct a statement that you made; even if the footing drain is found to be installed above the footing, it does not mean it is not to code. The residential building code does not require a specific side of footing location for a drain.
To address your concern: Foundation drainage is not required where there is no cavity below grade, and to the best of my knowledge, exposure to water does not effect the structural integrity of the footing. As such, we will not be replacing the existing footing drains that run on the west and east sides of the living room. In those locations there is a slab above grade, and there is supporting earth on both sides of the foundation wall.
I am also hoping that we find that the footings were installed to the side of the footing and we will just be able to tie back into them.
Here is the actual language from the IRC (your jurisdiction may alter this language on adoption):
R405.1 Concrete or masonry foundations. Drains shall be
provided around concrete or masonry foundations that retain
earth and enclose habitable or usable spaces located below
grade. Drainage tiles, gravel or crushed stone drains, perforated
pipe or other approved systems or materials shall be
installed at or below the area to be protected and shall discharge
by gravity or mechanical means into an approved
drainage system. Gravel or crushed stone drains shall extend
not less than 1 foot (305 mm) beyond the outside edge of the
footing and 6 inches (152 mm) above the top of the footing and
be covered with an approved filter membrane material. The
top of open joints of drain tiles shall be protected with strips of
building paper. Except where otherwise recommended by the
drain manufacturer, perforated drains shall be surrounded with
an approved filter membrane or the filter membrane shall
cover the washed gravel or crushed rock covering the drain.
Drainage tiles or perforated pipe shall be placed on a minimum
of 2 inches (51 mm) of washed gravel or crushed rock not less
than one sieve size larger than the tile joint opening or perforation
and covered with not less than 6 inches (152 mm) of the
same material.
The important language here is "at or below the area to be protected." In most cases, the slab is 3"-4", so a 4" pipe placed on top of the footing would not meet this requirement. Conversely, a 4" pipe placed alongside the footing will always meet this requirement, so that's where most people put them. Also, having a few inches of breathing room is always a good thing.
Your builder is correct that footing drains are not required where there is no space below grade. If the slab in the rest of your home is above grade, no footing drains are required.
> The important language here is "at or below the area to be protected." In most cases, the slab is 3"-4", so a 4" pipe placed on top of the footing would not meet this requirement.
I'd have a hard time arguing that a 4" pipe alongside a 4" slab isn't "at the area to be protected". But adding this part: "Drainage tiles or perforated pipe shall be placed on a minimum of 2 inches (51 mm) of washed gravel" means you typically can't set the pipe on the footing.
I am sorry, but I am still confused. Don't you need a footing drain when you build a house which half is on the slab and half has a basement? I have a lot of water that pools out around the area where the house is on a slab. Don't you think the water that pools around the footing and underneath the slab affects the footing and the slab?
I think what he has proposed will keep your crawlspace dry, if the top of the new drain is more than 6 inches below the top of the slab. I would want to measure the height of the slab and mark it on the outside of the wall near where the water is collecting. If for some reason you cannot measure down from the sill plate on both sides I would drill a hole thru and measure from the hole concrete wall.
Understand that this plan has risk, in that the footing will be exposed and excavating around it risks disturbing the soil under the footing that is holding up the house. You want to avoid exposing the footing to heavy rain be prepared to postpone the work if you do not like the forecast.
“Don't you need a footing drain when you build a house which half is on the slab.”
Not if the slab is several inches above the grade next to the slab.
Walta
Hello everyone,
I received a new contract from our architect/builder. He wants to warranty his work for 1 year. Does it mean that this new warranty is going to void our by default NY state warranty? Could you please help me? See the contract in the attachment.
You should use a lawyer for legal advice.
If I were presented with the hypothetical below choices, I'd take the latter. IMO, It's easy to understand and inspect, shouldn't be that expensive for your small space and should be highly reliable for the life of the house.
1) A builder doing some speculative, partial drain repairs with only a limited 1 year warranty. OR
2) A sump, a battery backed up sump pump and a raised floor to let water flow to the sump. Say a 90 day warranty.
It's a highly likely that a marginal repair could work for a year and then fail in a subsequent year with more rain or snow. Another 5 years of warranty after the repair might be OK.
As Jon mentions above, we're not your attorney, and you should have one before signing any such contract. One that is familiar with construction law in your jurisdiction.
That said, I would object to the trigger for determining the work was unsuccessful. It is too vague. "Excessive precipitation" can mean anything from a full-on hurricane to a bigger than average thunderstorm. There should be a quantifiable trigger, and the codes generally offer one. Your local plumbing code probably has design requirements for the roof drainage system. Something like 3" per hour for a 15 minute duration, or 12" per day. At least use the same design criteria. Base it on reports from the most local weather station you can find. If there's nothing in your local codes, Find the maximum 1 hour and 1 day rainfall rates for your area for the last 5 years, and set the trigger there.
And have your attorney take a look at the entire agreement.
I agree with the others -- seek the counsel of a competent attorney for contract review.
Regarding the "quantifiable trigger" Peter mentions, you can probably get info for this from your local city engineering office or someone like a county drain commissioner's office. These people deal with storm drain design and the like, and can tell you what would be the maximum reasonable flow for such systems in your area.
You do NOT want something in the contract that just says something like "excessive" since that's not defined, so you could have an argument some day. Using published data from a code book, or design limits from a recognized authority (city engineer, drain commissioner, etc.) should be acceptable to both sides and gives you something that is defined and can be measured.
Bill
Thank you everyone! NY state has a 5 years warranty for new houses. Is the warranty void of he is putting in the contract a new 1 year warranty?
You really need a lawyer familiar with your state to get an answer to that question. You’ll want to ask if your private contract’s warranty language can supersede a state law regarding home warranties.
Bill
Poliana,
It is insane to rely on legal advice you get on a building website.
Hey M,
I think we'll need to hire a lawyer. I was looking for an advice about the warranty. Didn't think it was a " legal advice".
Any advice about the terms of a warranty, and especially about whether a secondary agreement can invalidate a warranty mandated by a regulatory authority is "legal advice." You are also entering this agreement in lieu of pursuing litigation, effectively making this agreement a legal settlement of your claims against the builder. That also requires "legal advice."
The people on this forum know an incredible amount about houses. But none of us are attorneys, none are licensed in your state, and none have any relevant knowledge to answer your warranty questions. That's why everyone is giving you the same advice - discuss this with a lawyer familiar with the facts of your case and the requirements of your local jurisdiction.
Thank you everyone for your support!
Clearly your builder paid a lawyer good money to write this agreement. You would be a fool to sign it without having paid a lawyer to read it.
A few questions come to mind when I read this agreement.
1 Why is he off the hook if the crawl space stays dry for 30 short days? You want a dry space for the next 30 years. Should a one in 500 year weather event occur most if not all buildings will get wet inside. Because of this no one should put in the agreement that the house will always be dry.
2 Why does he want you out of the house while he is working? Will this work require the power, water or sewer service to be interrupted, if not what is he trying to hide?
It does sound like your builder wants to make this right and I am betting future project will have better drainage. He is getting an education at the school of hard knock.
Walta
It's November 2020 and we still have water in our crawlspace. The architect replaced the footing drain and waterproofed the foundation around the crawlspace. He did the work during the summer 2019. His plan was to have the work done in two fazes: one was water proof and change the footing drain. Second: in a case that we still have water coming through, then he will do a drain under the slab. The water came back, but the architect doesn't answer to our emails anymore....since April. My husband hired lawyer......
https://www.lowelldeutschlander.com/
Poliana,
I would cost out the expense of having the subslab drain installed (possibly with a sump in the crawl space. Doing this work may be less expensive than the legal route.
I'd reread #14 above and compare the legal route ($, time, risk of losing) to the fairly simple task of adding a sump and a new floor above the slab in your small basement.
I am guessing you have not meet with the lawyer as normal advice is to not post about the problem on the net as you may put something out there that could hurt your legal case.
Did you end up signing the agreement your builders lawyer wrote in July?
Without rereading this thread why not raise the floor of the crawlspace about 10 inches 8 inches of clean stone and 2 inches of concrete. It seems certain the any water would find its way into the drain well before it would get above the new slab. The slab is not a necessity it just makes it more pleasant to work in the space so just the stone and a layer of plastic would do.
Walta
Poliana, the suggestions to price out having remediation work done and doing a cost comparison to the legal work (your lawyer can probably give you a rough estimate of what that cost might be), are good ones. INTERIOR perimeter drains exist that require only a relatively small cut around the slab next to the inside of the exterior foundation walls. These can be very effective when installed correctly. There are contractors that specialize in basement waterproofing and drainage, I'd recommend calling one for some quotes.
My dad was an attorney. He would tell you two things regarding legal work:
1- Sometimes the best advice was to NOT go to court, even with a winning case, because the legal costs would exceed the project costs. He said clients always hated to hear this, but it was honest. You can have a winning case and still be better off NOT going to court. This would be the case for you if the estimated legal costs were to exceed the quote you got from a basement waterproofing contractor.
2- Only the lawyers ever really win in court. He liked to say this. The lawyers always got paid regardless of how things turned out for the clients.
I would also be careful of any lawyer telling you you have a "slam dunk" case. Sure, those cases are out there, but remember #2 above. An honest lawyer should go through the potential downsides of legal action with you. That includes talking about the costs of legal action vs the costs of just fixing the issue on your own.
Be careful and I hope you're able to resolve the water issue you've been dealing with.
Bill