Does anyone know the best material to apply to basement walls, on both the inside and outside, during construction so as to guard against potential leaks? The foundation / basement is built into the side of a hill with the up hill side basement wall about 8 ft below ground level. Any advice most appreciated.
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Drain tile.
And after that: Proper landscape grading.
You need a waterproofing "system", on the outside. That would include either a sprayed on or sheet membrane, some kind of drain board, a drain tile system that exits to daylight, and the right backfill material.
What's done on the inside is more of just a backup plan and might consist of a drain tile and stone under the floor.
A lot of this is dependant on the site conditions. ie soil type, etc.
Is the basement concrete or masonry?
Is the basement concrete or masonry?
The walls are cinder block and the floor is concrete slab. And thanks for writing in everyone.
More specifically, in an area where ground water is a problem there should be a loop of drain tile on the outside and another on the inside, connected to each other at 2-4 spots. The tile should be placed below floor level. In places where groundwater is especially problematic some additional tile runs across the middle of the floor may be justified.Drain tile should drain "to daylight" or into a sump. Simply draining into a "dry well" that's on roughly the same level as the house is insufficient and may actually make matters worse. If the daylight drain opening must be some distance away it may be wise to also have a sump (with pump), in case the drain clogs.Give some thought to using the drain tile system for radon mitigation. This is quite simply done if planned in advance.The exteriors of the basement walls should at minimum be treated with a sealant spray -- now generally a tar-like elastomeric coating. Over this is applied styrofoam sheets, both for insulation and to protect the coating from puncture by rocks, etc. There are also new drain plane systems now available for application to the walls. These vary, but one type resembles corrugated cardboard, and helps conduct moisture in the soil down to the tile system, before it can get to the wall.The floor is remarkably difficult to seal, but generally there should be a plastic vapor barrier above the drain tile plane and below the slab, and also styrofoam insulation.Final grade is important for a dry basement. The grading should be done so that there is no standing water anywhere within 10-20 feet of the house, and the soil is sloped away from the house for at least 5 feet (preferably 10). This will require maintenance, since the disturbed soil around the foundation will subside over time, potentially producing a depression adjacent to the house.
If your view never changes you're following the wrong leader
Edited 12/23/2007 9:15 am by DanH
Contrary to DanH's idea to tie the interior drain pipe and exterior together. Leave them separate so the outside doesn't introduce water to the interior piping.
Here's the system I've used on our in the hill on the backside house (block).
1. Foundation coating and what was called and the time-Warm and Dry. A 2'' rigid fibreglas system from Owens Corning. Layed over the exterior of the block. Gives insulation and a water drainage path down the outter 1/4'' of the fibreglass. Water gets wicked down to the footer.
2. Side of footer-perforated drain pipe in a sock or covered with landscape cloth-back fill ALL STONE. No dirt on the top either. Figure a way to landscape your perimeter w/o dirt (around the house and at the drip line. I have no gutters.
3. Interior perforated drain tile with fabric and covered with stone. Acts as a second line of defense and perhaps a passive radon drain if you come up with a "vent" stack at the outside.
4. Both drain systems run out the downhill side to daylight. (on bed of rock to limit erosion.
5. Create a swale on the uphill side to direct ground water AROUND your house. No use trying to collect uphill water and then try to take it away. Helps keep saturation around the house to a workable level.
Best of luck.
Bone Dry for 18 yrs.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Thanks DanH and thanks for the web site, stevenplane. But I should have mentioned that I can't follow the "outside" advice because my contractor already filled in the backfill in the front of the house. He said he didn't think I'd need a French Drain and the only preventative thing he did was to paint some kind of "white stuff" on the outside of the foundation walls so obviously I don't have access to those walls any more because the front, critical wall is now under about ten feet of dirt. I still feel sick to my stomach for not speaking up and asking my contractor "are you sure you know what the Hell you're doing?" but I didn't. Before my present house under construction I had another pre-Katrina house on the same spot with another sub-terrainian basement and I'd had nothing but aggravating tormenting foundation leaks for the 12 years I lived there (I know it's a terrible thing to say but for me Katrina was the hurricane from heaven). Well, now my new house still-under-construction basement is leaking and I'm so pee O'ed I can't even see straight. And now all of a sudden my general contractor is an irrigation expert on landscaping and re-grading technology and knows all the latest stuff. Well, maybe so, but that's still not an excuse for not having treated the wall right in the first place. (And 3 or 4 dump truck$ of top $oil - what's that gonna' to run?) So I guess all I'm really looking for is a good interior penetrating sealant for concrete and cinder block. It's not the greatest fix but it's all I've got. Sorry for not being a little more clear about that.
Did he even install drain tile? You can dig the foundation up now, or you can do it ten years from now. Now is easier and cheaper.And by all means do not let him pour the floor slab unless there's drain tile in place on the inside. If the slab is already in place I'd advocate cutting it open to install tile if none is present.
If your view never changes you're following the wrong leader
You can dig the foundation up now, or you can do it ten years from now. Now is easier and cheaper.
Yea, I know. Took the words right out of my mouth. But now you're almost in lawyer territory.
What calvin did in the above post sounds made to order for my foundation but if I insist on my contractor undoing his mistake I'm sure, one way or the other, I'm going to be the one paying for it.
made to order for my foundation but if I insist on my contractor undoing his mistake I'm sure, one way or the other, I'm going to be the one paying for it.
Ah, just how far along is this house?
If the GC is messing up foundation details now, what other details will he mess up later? 5/32 rooth deck instead of 7/32 (actually heard a hack say "Iz all 32's, doan matter which'ns ya use; all't same").
Now the next big question is--what do the drawing show. If your drawings (especially those that had to be presented for permits) show details left out of the construction, then you are already in "lawyer territory." Oh, and in 20, 30, 50, years, the GC's name will not be on the title, yours will. Want to sit in that uncomfortable wooden chair when the oppsoing attorney asks things like "So, you willfull, and knowingly, allowed these unsafe and dangerous practices to go on . . . "
Occupational hazard of my occupation not being around (sorry Bubba)
sit in that uncomfortable wooden chair when the oppsoing attorney asks things like "So, you willfull, and knowingly, allowed these unsafe and dangerous practices to go on . . . "
I know, I know, ....... boy, it sure sucks being me.
You're saying he'll spit on your steak?You should at least double-check what local code has to say. If it's not up to code you really should call him on that.
If your view never changes you're following the wrong leader
You're saying he'll spit on your steak?
No. I really do think he's honest. But he's building my house on a cost plus 20% basis and when he hands me those itemized expense reports I can't make out whether or not every item on those reports are for my mistakes or his. (And I have had him change things as we go along - there's plenty of blame to go around for everyone.)
Edited 12/27/2007 8:54 am ET by bayouelton
Trust us: An "interior penetrating sealant" won't do the job.
If your view never changes you're following the wrong leader
Sorry about the bad news and luck.You won't ever seal a basement from the inside. not possible.The best action might be to dig up that front wall now, before all the landscaping is done, and add the drains and waterproofing.Old basements are reworked pretty regularly just like this.A medium to large guy named Alan, not an ambiguous female....
NOT that there is anything wrong with that.
Yeah, our neighbor across the street just did the big dig on their house ca 35 years old. We have in-floor heating duct that sorta serves the purpose of tile and does the job for us -- so long as we watch the grade and keep the downspout extensions in place. (About time to mud-jack the driveway slab again, after 25+ years.)
If your view never changes you're following the wrong leader
Double what DanH says. Dig it back out now while it's still easy & cheap. In my neck of the woods, the inspector wants to see the foundation drain when he does the pre-backfill inspection. You may want to check with your own inspector. If the builder skipped a required drain, he may have to dig it out on his dime. (He should anyway, IMHO.)
Mike HennessyPittsburgh, PA
I wonder if the "white stuff" was drylock?
I don't know, Matt. If I find out I'll let you know.
bayouelton,
beyond the advice you have gotten already, I think the best thing you can do is put a couple of feet of 1' or 2" clear crushed stone outside the foundation wall. When or if the drain tile collapses, the stone will still provide drainage. The stone will also reduce backfill pressure against the wall.
I presume that if you have backfilled 8' high against a block foundation then the basement slab has already been poured.
Interior coatings never work.
Ron
Thanks, Ron. And you're right, the slab has been poured. But to be perfectly honest I really do think my contractor will fix the problem based on the conversation I had with him. The best thing I've got going for me is a couple of nosy, retired neighbors next door with big mouths who have nothing better to do than micro inspect every mistake he makes. And what's ironic is that he prides himself on his foundations. I'm absolutely convinced he's scared to death my foundation will leak after construction is complete and my neighbors will blab it all over town.
No worries if the slab is already poured. There are many "existing basement" drainage systems out there that should suit your needs. It's a little bit of a pain but doable. You snap a chalk line a few inches inside of the perimeter foundation wall, cut it all the way through with a concrete saw, and bust those few inches of concrete out. Then dig down and put a trench drain in that feeds to a low point...a pit with a sump pump that drains well away from the house.
Not having drainage is a big deal. EPDM not covering the footing is probably nothing.
A word of caution on that method. Often the continuity of the slab from wall to wall is used to brace the walls against lateral pressure. Engineers may use the slab as a part of their calculations for the footings and walls. Same theory as a floor diaphragm.
They can't get your Goat if you don't tell them where it is hidden.
" I really do think my contractor will fix the problem based on the conversation I had with him."If he is planning to fix it by putting "white stuff" or anything else on the inside he is wasting his time and money looking like a clown. If you let him, you are playing the comedian.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
If he is ... putting "white stuff" or anything else on the inside
No, no, no. I don't think that's what I said, at least that's not what I meant. The inside treatment is my idea, not his. And as a backup only. I was just putting out feelers to see if anyone here had heard of a product called Damtight manufactuered by BLP Mobile paint, which is promoted for inside use. My contractor wants to put in a sub-terranian type French drain. I don't know if he's ever even heard of Damtight.
Edited 12/24/2007 1:51 pm ET by bayouelton
Edited 12/24/2007 1:56 pm ET by bayouelton
This is just one of hundreds of products meant to seal the block. Problem is, it ain't permanent and, even if it works, it just results in flooding the block cells with water. You can drain the water if you drill each cell on the bottom course and drain them to an interior french drain. That means you need to deal with interior water, which usually means a sump pump, which doesn't work if the power goes out, BTW. And, most good interior french drain solutions I've seen have had thick plastic panels installed inside the blocks to divert the water to the drain, not paint.
An interior french drain is what you'd do if you had a house build before foundation drains became common and you had to fix a wet basement on a budget. It's a solution, but not one you should choose unless you have to. The best way to keep the basement dry is to divert all the water BEFORE it gets into the block. That means properly sealed, drained and landscaped exteriors. Period. Tell your contractor to put a french drain in HIS house -- you want yours done properly. FHB had a good article a couple of years ago, IIRC, that showed a properly constructed foundation drainage system. I'd suggest you check it out and require the contractor to dig & re-do properly before he gets another draw.
Mike HennessyPittsburgh, PA
Thanks Mike. All of what you said makes a lot of sense to me. I never really did like the idea of an interior seal. It's just that it's so easy to do I kind of thought, "well, why not."
"well, why not."
The why not is that it probably will buy the contractor time-how long is up to the rain gods. By the time you figure it's failing is the time he's moved on to bigger and better victims.
Best of luck.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Sorry, but your guy who backfilled without providing drainage and membranes first is an idiot. Don't bother paying him until he digs it out and does it right. That is like pouring sugar in your gas tank or pissin on your new shoes and socks! Idiots like that ought to be run out of business.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
re: the tile & right back fill...
something I've seen lately while looking at a few prospects... if the back fill is dumped on the platic drain pipe without care it get's crushed leaving it pretty much useless.
air gap membrane is a must. http://www.systemplaton.com is one example but there are dozens on the market. Good drainage is the most important thing.