[PonchoV8]

I have a full basement with 8 foot ceilings, and the house was built in the mid 60s. It can get pretty humid at all times of the year. It's not quite half finished (vinyl tile floor on that portion) down there. Wonder if there is anything you people have used to seal out moisture some? I doubt there was a moisture underlayment under the slab when poured.
Thanks,

[Cammer-6]

first step is to remove the moisture from the outside.
How far below grade is the basement floor?

[Jeff Hamlin]

When I had my house up north we had a full basement.
We had water & humidify issues after taking care of the seepage (French drain& pump) I then put in a dehumidifier & plumbed it in to the drain so it was on 24/7 on med setting.
It worked great.

[mike nixon]

The way it's done around here is to dig a trench around the exterior off the house foundation and lay a tile in the bottom to divert the water away from the house. Cover the exterior of the walls with foundation sealant,backfill it with washed stone, and lay a thin layer of topsoil on top of it for asthetics.

As stated above you need to get the water away from the structure.

Mike

[4dblnkldude]

In all of the new houses I work on they put 2-3 coats of drylock on the walls and and on the floor. They then paint the some light tan color. It also makes the basement nice and bright not dark and dingy. I'm sure that some type of drain is also put in, as previosly stated, but can't help you there.

[PLAY400]

Live in the country of basements.

Ground water: Put a footing down, pour the wall on the footing, run weeping tile along the footing teeing it into the basement at several locates where it finally ends up in a sump pit. Cover with gravel and backfill. When the sump fills a pump discharges it away from the house. Drainage taken care of. Inside if basement not vented well add some return vents, use the AC and if required a dehumidifier in the basement. I have an old place and we go from heat, to dehumidifier to AC. Found the AC alone does not drop the humidity in the basement fast enough. Only the materials have changed over time.

[PonchoV8]

The basement has no A/C. It only has ceil-heat in one finished area, which is part of the moisture removal issues. Five hundred feet is finished; 1000 is not. I could run a dehumid and fix the problem, but maybe not after I finish it into living space.

How much moisture wicks up thru a slab floor normally? Will a drylok product coated on the interior block walls seal out permeation of moisture to the inside of the basement?

[PonchoV8]

Here's a pic of the house just about when we bought it--notice the algae on the garage door.

HERE: (Front door is hidden behind the bump out at the middle on the house). The front side and under that garage are covered by the grade. The basement doesn't extend under the garage, but it's 1400 feet of basement--500 finished on the back half where you walk out the back yard. The grade slopes off quickly down both sides of the house to a walk out basement.

There's no water accumulating inside no matter how wet it is outside. I don't see any seepage either. It's just damp feeling. There's a large storage area in the basement against the garage side at the front of the house that has no windows--it's walled off from the finished part of the basement. Away from the garage on the other front corner there is a large Weeping Spruce, or a Blue Spruce that you can see. It's right bam against the house, which would possibly be destroyed if I dug down the foundation over there.

Up on the surface out in front of the garage there's always been a water accumulation issue. The street water at the driveway entrance has a berm built up so the water stays in the street. It will still accum in front of the garage door though--as seen by the green growth. Perhaps that area is the majority of the issue. When I rework the front walk and driveway, I can drain that area better. Hard to believe that the water table under the garage could be part of the problem. If it's anything, it's pooling from the front door to the driveway. Actually 480 finished down--1400 total feet of basement.

[sdbob]

The water table varies with the season, weather conditions and soil . My exp. you want to try to prevent dampness.As others have said drains around the outside(try to keep bushes-trees away from near the house if possible as roots will clog the french drains).With gravel-stone filled to the top.then some kind of landscape fabric on top to filter out dirt again so the drains do not get plugged. This is the one approach that has worked for us.Thsi will help the dampness then use your paint,dehumidifier.Not sure of your budget,soil,or dampness conditions.The stone and pipe,black tar method is basically labor work.

[PonchoV8]

Budget isn't a problem. We live modestly for the comfort. Where to start, is the problem. Getting started is the problem. This house needs--roof, gutters, driveway, windows, exterior refinished, landscaping. Gutters are probably part of the moisture issue too.

[stags]

Doug, I agree with sdbob on first diverting as much as possible away from the basement. Second, a penetrating sealer, DECO-20 is a good one, will work much better and longer on your slab than a surface sealer like paint. These products penetrate and crystallize INside the pores of block/concrete so they are much more effective and long-lasting. Check with a local masonry supplier as there are many brands out there. Try to get a water based product so there won't be any fumes to deal with.

A dehmidifier is also a good idea. Remember, moisture-laden air will accumulate in your basement from above so someting is needed to extract it. AC will work but if that's not feasible get a decent DH and make sure it's plumbed to sump or outside to avoid recirculating the water. Mark O.

[bankbook]

I recently Epoxy coated my basement floor and painted the walls with the waterproof paint. I had similar issues of dampness but no water. Since doing that I have NO dampness at all. I am in the process of finishing the basement off with a subfloor then the rest.

The stuff I used is the same that they put on Garage floors. Epoxycoat.com great stuff.

[PonchoV8]

Okay. I'll check on that product as well as the DECO-20 which sounds like a good product. I'll have to strip the grey paint off of the floor. I guess it's not too big of a deal to dig the foundation from the front door to past the garage and down the side. The other side is where that tree is and the ground slope is better. I know it may be patch workish, but I've got an idea for the driveway water issue too with a cut across it halfway from the street for a drain to take that water off to the right of the house instead of to the garage door. Another in-pavement drain in front of the garage door for the same purpose, and to help drain that shrubbed area approaching the door. New gutters with 4" downspouts first to make sure the water is being diverted correctly.

Soil here is usually red clay. This was pasture, but actually it's rocky clay in my yard. The rocks I've seen in the yard are the small, sharp white rocks that will cut your finger if you fling them too hard. The rest is clay. Moisture can be a real issue. We've had drought, but this area gets more rain than Seattle in a normal yr.

[Cammer-6]

As you most likely know clay will not drain,making your problem worse.
It looks like you can use the lowest corner at the rear to have everything drain to.
How deep is the clay and how high is the water table?

[george kujanski]

I put two coats of DryLock on the walls and a tile floor when I finished mine and it is still damp in the basement during the summer.

I don't think it's due to moisture intrusion as such; my sump system is working and I know I have a plastic moisture barrier under the slab. i think since the temp in the basement is typically lower than the air temp outside, the relative humidity levels outside during the summer can be in the 80's and 90's so in the cooler temps in the basement the RH gets higher.

I have a dehumidifier with a digital display and when I turn it on it shows high 60's but after running for 24 hours or so it's down below 50, and it feels very comfortable.

So in my case, even with proper techniques used, I think a DH will need to be used.

George

[PonchoV8]

Checkola.

Cammer, I dont' know how I would determine the water table.

[69goatboy]

The problem with paint on systems is the outside of the concrete is still not treated (therefore the water is still getting to it and will wick through it) , all you are doing is coating the inside, and water WILL eventually find a way in.

Eventually epoxies and the like WILL fail. Even if they do not, you are trapping the water IN the concrete which will eventually erode the concrete.

The way I see it, you have two choices: Prevent the water from getting to your concrete or deal with the water once it does gets through.

I think the route the Mike Nixon suggested is going to be your most sure and best bet to keep the water from getting to your concrete in the first place.

There is a company (Everdry?) that will dig a trench around the INSIDE perimeter of your basement, which then leads to a sump, then discharged. Which would deal with the water once it does gets through. My aunt and uncle have this system, it can be finished over and you'll never know it's there.

A dehumidifier is a very good idea. I run one during the summer months at my house.

[Cammer-6]

Originally Posted by PonchoV8

Checkola.

Cammer, I dont' know how I would determine the water table.

Dig a hole at your lowest spot with post hole diggers at least 4 ft down.
If you dont see water in a day or so youre OK.
Trench around the basement area below slab level,but do not disturb the footers.
drainage tile the trench and slope at 1/8" per foot or better to the lowest spot in back corner. Plant a couple of clean 55 gallon drums
under this last tie in of drain pipe and plumb into it.
I ventilate the bottom of drum with an axe so it will drain.Not an easy project but youll never stop the water from coming in by using sealer on the inside alone.

[PonchoV8]

My old time gauge says 87% humidity in the storage room that's against the front side and garage side of the basement. I don't know how accurate it is though. There's no light, no Sunlight, but I keep a fan blowing all the time in there.

[stags]

Doug, I take it you don't actually have water running down your walls or welling up through the floor, correct? If so then I don't think you really need to chop up your floor and put a drain/sump in. A combination of diverting stormwater away from the house; sealing the walls with a penetrating sealer; and a good dehumidifier should get you down to an acceptable level.

A DH alone would probably work but it won't have to work nearly as hard if you divert as much water as possible.

I've been using penetrating sealers like DECO-20 for many years. They aren't perfect but they are very effective and long-lasting, especially on damp block walls.

It's not that the drain/sump operation doesn't work - it does - but it's very expensive (or labor intensive for DIY) and may not be necessary.