Solid masonry house, solid poured concrete foundation and basement walls, built in 1940. Two different problems that allow a lot of water to enter basement:

1. On the east side, the sidewalk adjoining the house has pulled away from the foundation wall, leaving a gap as small as a crack to as much as an inch or more. When it rains and blows from the east, water goes down the wall, past the gap at the sidewalk, and into the basement below.

2. On the west side, which has a gravel bed running along the wall, there is a 3/4 inch hole in the basement wall about a foot above the floor. When there's a good rain from the west, especially if the ground is/gets saturated, water pours in that hole like a garden hose. I want to plug that hole FROM THE INSIDE. I know that excavation and dealing with it from the outside is the best/surest way to fix it, but that's not going to happen.

Does anyone know the best materials to use for either or both these issues? On the east, with the sidewalk separation, I'm expecting to need some kind of filler before a topping of...caulk? Whatever it is, it needs to be flexible, because that sidewalk will heave and settle a bit with the seasons. Also, the caulks I know about might have trouble curing in an inch-thick application.

Thoughts? TIA.

Caulk is not good for an inch thick application generally. It will cure and stay put usually in that IF you can get it to cure without oozing out.

3M 5200 (caulk) will cure even underwater and is extremely strong stuff, can be found at Lowe's or HD.

It sounds like you need a 2 part epoxy over caulking for your application. There are several that will cure underwater, or wet.

I've heard of 3M 5200; I'll check it again.

As to epoxy on top of caulk, I think epoxy would harden to the point of cracking/breaking free from the wall when the sidewalk heaved in winter.

Thanks for the thoughts.

The first thing I would do personally is to check the grading around the entire foundation and make sure my existing drainage is working properly. I had a reverse grade on a backside basement window that was causing water to roll in over the window well unobstructed. Until I got the grading right it didn't matter but once it was corrected end of story. In your case it sounds like you will still have some things to address. Maybe some pictures might help get better responses. I'm wondering if some sort of flashing might work on the long gap. For the hole you might try a hydraulic concrete and possible sealing it after. Caulk would not be my first choice either. Not sure that would be appropriate for the other situation.

Hopefully someone more experienced can chime in.

Is the 3/4" hole an all the way through the wall hole possibly for a previous pipe or line? There are expandable rubber plugs in different sizes made which tighten with a wing nut or hex nut. What about pushing one or more of these down the hole then using epoxy or a caulk for the last inside inch of the hole? I'm no expert on this but it seems like that would give a good strong seal. Google comes up with all kinds of these plugs.

quote:

Originally posted by Gene Hillman:
Is the 3/4" hole an all the way through the wall hole possibly for a previous pipe or line? There are expandable rubber plugs in different sizes made which tighten with a wing nut or hex nut. What about pushing one or more of these down the hole then using epoxy or a caulk for the last inside inch of the hole? I'm no expert on this but it seems like that would give a good strong seal. Google comes up with all kinds of these plugs.

It has occurred to me that the hole is from previous pipe or line; it seems too neat to have just eroded from some small opening on the outside. I'll look into those plugs. Thanks.

quote:

Originally posted by bigeinkcmo:
The first thing I would do personally is to check the grading around the entire foundation and make sure my existing drainage is working properly. I had a reverse grade on a backside basement window that was causing water to roll in over the window well unobstructed. Until I got the grading right it didn't matter but once it was corrected end of story. In your case it sounds like you will still have some things to address. Maybe some pictures might help get better responses. I'm wondering if some sort of flashing might work on the long gap. For the hole you might try a hydraulic concrete and possible sealing it after. Caulk would not be my first choice either. Not sure that would be appropriate for the other situation.

Hopefully someone more experienced can chime in.

It's not a grading issue; the grading is very good on both sides as it slopes away from the house and downhill. Hydraulic cement might bear consideration, but I think Gene Hillman might be onto something above. Thanks.

I don't understand how water running through a crack in a sidewalk ends up in the basement. The basement wall's integrity should be independent of the sidewalk.

As for the hole: Hydraulic cement I should think would be the proper solution.

Flexseal or FlexTape....

quote:

Originally posted by ensigmatic:
I don't understand how water running through a crack in a sidewalk ends up in the basement. The basement wall's integrity should be independent of the sidewalk.

As for the hole: Hydraulic cement I should think would be the proper solution.

It's not a crack in the sidewalk; the sidewalk abuts the wall, but there are gaps between the edge of the sidewalk and the 90 degree "joint" with the wall. There used to be tar smeared at the joint, but with age and settling and cracking, it's not doing any good. If I can seal the gaps, and make a good, flexible joint with the wall, it will be a very good water shed given the favorable gradient of the sidewalk away from the wall.

And to your other point, and bigeinkcmo's question below, yes, it is possible there could be cracking in the wall below grade, but more likely, I think, is that there could be cracking where the foundation wall meets the basement floor. All of that is six or eight feet below grade, and not evident from the inside.

quote:

Originally posted by amals:
and not evident from the inside.

where is the water coming in then?

As for the hole, if it is 'pouring like a garden hose', then there is a buildup of water against the wall, above the hole, creating pressure - hence the suggestion to check your grade/drainage.

In both cases, your problem is better addressed outside, not with something in a tube (maybe the hole, but you're on the right track with that)..
I've had a couple wet spots in an otherwise dry basement when we've had stupid amounts of rain (think 10" in 5-6hrs). I used an epoxy to inject into the spots & brushed them over with a rubber glove coated finger to work the epoxy into the crack. It's held for years. In another spot that was weeping around a pipe, I used a polyurethane product that I don't remember the name of - it's held for 6mos w/o a trial (fixed the gutter downspout that wasn't flowing far enough from the house).

Give these guys a call. I've used their epoxy with great success!

http://postconcrete.com


It's a 2 step process-
You seal the inside of the crack/hole with an epoxy putty, with a port. Let it dry.

You then inject a thin epoxy into the port that fills in the crack.

This epoxy is thin. Like SUPER THIN! Almost the same as water. It seeps into the cracks and hardens up stronger than concrete.

The epoxy comes in a tube similar to a tube of caulk, and all the equipment you need is a caulk gun.

Use this, with a backer rod or cured "great stuff" for large gaps:

https://www.amazon.com/dp/B00461GOKY/

Check Lowes or Home Depot for the brand name Silka. In gold/yellow tube. I bought one of their products that is a caulk like consistency and it expands and shrinks with the temperature. They also have some stuff that feels like a play dough. You roll it out and have to use a torch and it literally melts into the cracks.

You want to use Water Stop.

I had a crack in the basement floor and chiseled a V in the crack and then filled with Water Stop and after it had dried for some time, I used a brick and some water to finish it level with the floor and you can't even find it after I painted the floor.

I also used it to fill a hole in the basement wall that let water in when it rained hard.

https://www.lowes.com/pd/quikr...ALw_wcB&gclsrc=aw.ds

quote:

Originally posted by arcwelder76:
Use this, with a backer rod or cured "great stuff" for large gaps:

https://www.amazon.com/dp/B00461GOKY/

This is along the lines of what I was thinking for the east wall gap; something to backfill then something to seal. I'll check it out.

any Urethane caulk will stop the leak, if between the sidewalk and house, use a self leveling caulk. it will flow to the voids in the crack sealing as it cures. do not use on vertical cracks or joints.

do not use anything silicone! it will make the edges non-stick and will not allow any other caulk to adhere to the materials.

SL-1 (self leveling) and NP1 are what most "waterproofers" use to caulk. but you can pick up similar materials from HD or Lowes.

ymmv
john

Some good ideas here; I will investigate. Thanks to all.

I watched 6 youtube vid's on basement waterproofing, during construction.
and six more vid's on
waterproofing repairs , long after construction

then I watched 4 more vid's on why basement waterproofing fails.

My conclusion is that the term "permanent waterproofing"

is actually between 5 and ten years in real life.

I don't know everyone in tiny town but of the dozen people that I do know,

only three have homes with completely dry basements. and those three are over 20 years old

crack-stix is what you're looking for. It's a 1/2" diameter rope like material made for concrete expansion joints, you stick it in the crack and melt it with a torch and it conforms to the crack and seals it, you could probably do it once, or stick two pieces in there to take up the 1" space. It's what you see the cities use on sidewalks.


https://crackstix.com/