External waterproofing foundation walls of a basement (Tanking)

[wak]

I have solid foundation walls on each side of my house that are leaking because the previous owner allowed the gutters to drain inward and the ground sunk in towards the house.

I was going to rent a back ho and dig a trench around the house and water proof it.

I could not find a web site that answered all my questions. If you know of one could you please post it?

Some questions I have is what is the ideal long lasting sealant or membrane I should use and where would I purchase it?

Should I use hydraulic cement to fill the cracks or an asphalt product sealant?

When I back fill it should I use, sand, gravel, rock because it will drain faster and relieve water pressure?

The house is about 8 years old, has sump pump and drainage system underground.

Thanks

[HayZee518]

ideally once you have escavated near the bottom of your foundation and/or footing, you should install a perforated drain tile leading the out put away from the house. coarse gravel followed by smaller gravel should be on top of the drain tile. a permeable membrane should be put in next to keep small stones and sand from infiltrating the drain tile. lastly use sand and then your top soil to complete the repair.

[Drywall DIY Guy]

Perhaps Try This First

If you have some good drainage away from the house, simply sloping the ground down away from your house will take care of this at the cost of some sweat, perhaps a 1/2 truckload of fill, and use of your shovel and wheelbarrow. To be sure, you can lay some plastic down as well sloping it down and away and cover this with the dirt.
I helped my neighbor do this about 10 years ago. He had 4" of water in the basement but has not had a problem since. His problem was similar to yours - ground settled near the foundation and lack of proper gutters.

You want to get rid of the water. Waterproofing the walls is not the solution - the hydrostatic pressure against the walls is just as high as if you were holding back an entire lake and the water will find a way in eventually. (Note that it is the depth of the water that dictates the pressure. So a 1" thick layer of water at a depth of 2 ft exerts the same pressure as an entire lake of water 2 ft deep pushing against the wall.) If you do not have drainage away, then waterproofing, coupled with drain tile and a sump pump to move the water away would be your solution - and that would require some heavy equipment.

But the best and cheapest solution, if possible, is to divert the water away from the house with landscaping and gutters.

[pushkins]

You also must be VERY careful when excavating around your basement walls, the trench will ultimately end up about 8' deep and needs to be wide enough to avoid trench cave in, especially since you say that you currently have water issues that means that the soil around your basement is saturated in water. This sort of work isn't for a novice.
As DIY guy suggested, I think your first efforts should be in re grading the land around your home to shunt the water away from your foundation.

How old is the house and what construction are the basement walls, poured concrete, block ?


Opps....I see it's 8 years old.

[wak]

I do have a perforated tile at the bottom and drainage system to drain, but the landscaping was neglected. I plan on landscaping away after water proofing.

If I do decide to dig a trench, what water proofing membrane do you guys suggest? Is this something I can get at Lowes, Home Depot or Menards?

Also, out of curiosity if the trench is 8 feet deep, help me understand the fill in measurements of a foot.

Does 3 feet of grade 6 rock over the tile, then follow by 3 feet of a gravel, then 1 foot of clay to stop top drainage then 1 feet of top soil sound about right?

Thanks!

[HayZee518]

ideally an impermeable membrane is the way to go, but this gets expensive. I used an ashphalt based foundation coating on mine and put it on rather thick with a deep nap roller. then tile, a bleed through membrane around the drain tile, gravel and top soil.

[wak]

Hayzee- can this waterproofing asphalt or membrane be purchased at local hardware stores?

Also when you said put the membrane around the tile, do you mean over it so it doers not get blinded by dirt?

What did you think about me laying a few feet of rock over tile then gravel then clay then top soil, is this correct? I'm asking because I don;t want to fill with soil or clay and find out I needed a faster drainage fill.

Thanks

[HayZee518]

the drain tile will get rid of water throuigh its holes. the membrane wrapped around the drain tile allows water to go through but not sand and soil which will infiltrate through the gaps in the gravel just to clog the drain tile's openings. a large influx of water will flow along the insode of the tile and will dissapate through the drain tile's holes as the water travels the length of it.

[cyfreeney]

Here's a thought:

You did say that the house has some sort of drainage and a sump pump in place right?
And being 8 years old, chances are, it has some sort of damp proof coating or membrane applied to the exterior basement walls as well.
Building codes in most areas demand those to be applied to any new construction.
And yet you are still having serious water problems right? Chances are the exterior drainage system failed. It happens quite frequently, even when the homeowner takes all the precautions to divert the water away from the foundation walls.
I'd suggest you consider an interior perimeter drainage system instead. It can be installed internally, along the basement walls, without digging out foundations. It will collect all the water seeping through and divert it to a sump pump system (preferably including a battery operated back up pump) that will then pump out and away from the foundation.

The advantage of such systems is that, unlike typical french drains, the internal drainage systems can be serviced and flushed as needed without disruptive excavation. Internal drainage systems have been used with success for over 20 years now.