Basement Waterproofing vs. Water management

[BigguyZ]

So, I have a finished basement (well, mostly finished) that I have had leak a couple of times a year when it rains heavily. It's not constant that it leaks into the center of the room, but it definitely gets damp- or at least more damp than I'd like (the dehumidifier almost never clicks off in summer). There's no sump pump in the house so I obviously don't have any drainage system currently in place.

So... I'm thinking that the basement will be my first real large-scale rennovation for the house. What I'm wondering is, what's the best way to go? I'm a fan of Holmes on HGTV, but I'm not sure that I can afford the excavation + rubber + mesh + plastic sheeting + drainboard + draintile + catch basin + Sump pump solution. At least not professionally installed. I'd maybe be able to get away with DIY, but that's still expensive and I'd have to rent an excavator and hopefully not destroy my house in the meantime. I need to install an egress, so maybe I can attach the worst wall this way and do the window at the same time- either DIY or professionally.

The other solution seems to be drain board on the inside and installing drain tile. Or, I found information or drainage baseboard, which installs on top of the floor to provide a channel for the water to drain to. Or, you can try a system that coats the inside with a sealent or rubber coating.

What do you guys think? I'm definitely not wanting to invest in money and time in something that will not work- or make the issue worse (the baseboard solution involves drilling weeping hole in the block wall to allow the walls to drain easier. However, I do have to worry about budget here, since it's just me in the house and I have only my income to fund such a project.

Thanks,
Travis

[Russianwolf]

When my house was built, there was some water problems. Their solution was to install "French Drain" by jacking out the floor about a foot all the way around and putting in the drains to a sump pump in one corner. It works just fine as long as two things don't happen.

1) the Sump pump works. I've had a couple occasions where the float on the sump got stuck and didn't get to the on position. No Sump = flood.

2) the amount of water coming in is less than the water going out. I had one time where the sump discharge blew off the drainage line and was pouring against the foundation. The water went where it could which happened to be the Bilco door pit and right back into the basement. So everything that the pump was putting out was coming back in as well as all the rain water from the rest of the walls.

As said, this system works okay, but I'd like to get it were the water can't get in better myself. That's my shop after all and tools and water don't mix well.

[woodturner]

So, I have a finished basement (well, mostly finished) that I have had leak a couple of times a year when it rains heavily. It's not constant that it leaks into the center of the room, but it definitely gets damp- or at least more damp than I'd like (the dehumidifier almost never clicks off in summer).

You need to determine the source of the water. If it's condensation, drainage won't help. If it's drainage, the problem is most often due to grading and gutters.

Tape a piece of plastic to the wall, sealing all the edges, and leave it overnight. Which side of the plastic gets wet? If the room side, it's condensation, but if it's the side against the wall, it's drainage.

What is the grading like? The ground should slope away from the house a minimum of 1/4" per foot to a distance of at least 10 feet. Nothing should be planted within 5 feet of the house. Is the dirt surrounding the house clay or similar soil, or is it topsoil (topsoil will trap moisture and cause water problems).

Are the downspouts and gutters all clean, clear, and working? Do they drain at least 10' away from the house? Are the gutters sloped correctly (1/8" per foot minimum, 1/4" per foot is better)

[toolguy1000]

solve the problem outside the foundation, and you've solved it for good. it may be more than you want to spend, but look at the cost differential between a less expensive inside "quick fix" as opposed to a more expensive longer term solution. the difference, on an annual basis, will probably be worth the additional cost.

as far as what to do, i'd hire an engineer familiar with your area and hydrostatic pressure problems. and get ideas and estimates from as many contractors as you can. the more info you get, the easier the right solution will be to spot. good luck. foudation moisture can be a nightmare.

BTW, good suggeations from woodturner.

[parnelli]

You need to determine the source of the water. If it's condensation, drainage won't help. If it's drainage, the problem is most often due to grading and gutters.

+2 on everything woodturner said- but you really need to give us more details to "it leaks a couple times a year"

Where? When? Etc.

Outside of condensation, downspouts and grading are where I'd look first.

[cork58]

Lets go back to school for just a minute. Google "Sodium Silicate". Its been called waterglass for about a hundred years. This stuff really works! I use it for everything from coolant leaks in engines to sealing eggs. I won't spoil your education by telling you anything more, just google it.

[jdon]

If contemplating a French drain, consider the possibility of radon diffusing through the drainage into the basement from underlying soil. Radon mitigation adds a whole new dimension of complexity (and cost).

[conscience]

My company has done quite a bit of this and almost every time grading and downspouts were the culprits. Woodturner is dead on. If that doesn't stop the problem, exterior waterproofing and weeping tile should.

Any waterproofing membrane applied to the interior of the basement walls will fail over time if water is allowed to continually enter the basement walls. The constantly wet, or even damp, wall will eventually cause the bond between the waterproofing and the wall to fail. Many claim to solve the problem, and a few do for a while, but they pretty much all fail over time. Most only work on naked cement, so any paint or previous attempts at waterproofing will have to be removed for them to have any chance at lasting.

If you can't stop it from the outside and excavating is out of the budget (and it can be prohibitively expensive) install a perimeter drain system with a sump pump and basin. This requires the construction of the basement wall framing to be held off the cement by a couple of inches.

Like Russianwolf warns, pumps do go out (vacations?) leading to eventual flooding if the problem isn't corrected in time. There are several products which will monitor the sump pump/basin for flooding and set off an alarm when the water reaches a level beyond the standard height.

You could always install a second basin and pump on a different circuit, possibly solar, if you are really paranoid about it and have a boatload of cash, but it is cheaper to install an alarm.

[woodturner]

Lets go back to school for just a minute. Google "Sodium Silicate".

Have you found a good source for this at reasonable cost in reasonable quantity?