Water incursion

[patrick66]

My steel shop is built on the slab of my old house/shop, so it's a 65'x38' concrete slab with NO stem wall. When it rains, it does leak under the portion of the wall that is closest to the ground, on the NE corner. The framing of the shop is angle iron, and is bolted to the concrete. It is a nice building, but since there is no stem wall, I get water at that point.

What have you guys used to seal a problem like this? The water stays at that corner, which isn't a big deal in itself; because after the rain, I'll use the wet-vac to clean up. I've used silicone sealer along the outside of the wall and at the walk-in door threshold, but the only place it has been working is at that threshold. It takes a while to start infiltrating under the wall, but it does come through.

I've thought about putting about a two-inch-wide string of silicone along the base of the outside AND inside of the wall in the area where I get the water, but might there be an easier and/or better way to seal this up?n A french drain is in the works for the Spring.

 

[nwdustin]

great timing! Just walked out to my shed to grab something and noticed I got water in this year (it's been raining heavily in washington the past week or so).

My only idea is to dig around the perimeter of the shed and fill with gravel, I don't have any option of leading it to a street or anything, so that's my only idea.

Maybe have a gutter go to a barrel and then have a hose from the barrel to the street, maybe... I might look into that tomorrow to see if there is enough gravity to get the water the 50ft or so out there, hmmmmm

 

[theoldwizard1]

My only idea is to dig around the perimeter of the shed and fill with gravel, I don't have any option of leading it to a street or anything, so that's my only idea.

Search this board for the term "french drain" and "dry well". You are about half way there.

The important thing is to give the water "some place to go". Gravity is your friend. I dug a pretty good size "dry well" in the far corner of my yard and ran my french drain to it.

 

[James-W]

Maybe you could dig a trench leading to a hole where you put a 50 gallon drum and then put a sump pump in the drum with a pipe/hose going a fair distance from the building.

 

[T_R]

Splash back from the roof probably. I get that in heavy rains. Sill sealer helps with that. I didn't use it on mine, probably should have. I just get a little dampness, no puddles, not really a big deal. If you can unbolt the anchors and jack the building up an inch or so, you might be able to slide some sill sealer under. It comes in rolls.

 

[ilikedirt]

I have the EXACT same problem in my shop in a couple spots. Annoying as hell.

 

[bczygan]

How is the water getting in?

Driven rain against a crack that isn't sealed?

Water sheeting down a wall?

Is it running down from higher adjacent grade areas?

Is there any water forming on inside wall surfaces, or within the wall itself?

Bill

 

[Moss]

Do you have a gutter on the building? My building is on a wall putting gutters on sure made a huge difference all around it. If your grade is poor it would still help with long extensions to get the water away.

I'd be more worried about the water undermining your slab then anything.

 

[theoldwizard1]

Maybe you could dig a trench leading to a hole where you put a 50 gallon drum and then put a sump pump in the drum with a pipe/hose going a fair distance from the building.

that is called a "french drain" and a "dry well". If you have the space and make the dry well big enough you won't have to pump. (My dry well does over flow about 1-2 time per year. If I do NOT pump it, it take 2-5 days for the water to go down and the sode to dry out.)

 

[theoldwizard1]

I have the EXACT same problem in my shop in a couple spots. Annoying as hell.

French drain
Dry well

This trench is much deeper than it looks. 3+' !!

View media item 55494
After the water was removed from this trench, landscape cloth was laid in and a 2-4" bed of gravel was laid (to adjust the pitch). The PVC drain pipe (note holes) was covered with a sock and install with the holes up. Then more gravel up to a couple of inches below the ground level.

View media item 55497
View media item 55495
View media item 55496
Note the finished "French Drain" has a 2 high row of garden wall block up against the garage. (Top of first row is level with garage floor. Second row prevents splash on to siding.) The second row (also 2 high) will eventually go all the way across and hold 55 gallon rain barrels. The garden ares is higher than the garage floor (root cause for my water incursion in the garage). The garden could not be lowered because it would flood from the neighbors yards.

View media item 55498
This was about 5 years ago and it has been dry ever since !

 

[CTyankee]

We need a picture...If the water is collecting on the slab, I doubt a dry well or curtain drain is gonna help.

 

[patrick66]

I do have guttering on the North wall that is full-length, with two downspouts. The problem with water incursion existed both before the gutters and downspouts, and after. I'd thought about the French drain system, but will probably have to wait until late Winter to do that. In the meantime, I want to keep the seepage under the wall to a minimum.

The water is coming from runoff from my yard, which slopes down toward the shop at that corner. There is enough slope where the majority of the runoff runs along the East side of the shop and out towards my pasture. I'll take a couple of pictures in the morning and post them, so you have an idea visually of what I have.

 

[pmiranda]

French drain would be a quick fix for the real problem: insufficient grading around the building.

 

[nadogail]

French Drains are good.

Caulk where the water is coming into your garage under the wall. .o

 

[theoldwizard1]

French drain would be a quick fix for the real problem: insufficient grading around the building.

Grading can not always be changed or maybe I should say can not be changed to direct the water to a more suitable place on YOUR property. This is especially true if you have a small urban/suburban lot.

Technically, most cities/townships don't want you to connect your drainage to their sewer/drainage either.

 

[Radix2]

I see a lot of posts that imply a stem wall is a fix-all for these issues.

That is not the case when so often the real issue is improper grading or building placement (floor height) - the slab should be well above grade and the grade must slope away from the building. Without a serious constraint on space, the first choice should be to correct the grade before considering drains.

 

[acer66]

@theoldwizard1, looks great but is there a specific reason why you installed the pipe holes up?
I was always told to install them holes down but if that is wrong I might have to do quite some digging.

 

[bczygan]

Regrading is the answer.

 

[theoldwizard1]

Regrading is the answer.

Can not always be done.

Grading can not always be changed or maybe I should say can not be changed to direct the water to a more suitable place on YOUR property. This is especially true if you have a small urban/suburban lot.

 

[patrick66]

If I re-grade, that would make the very back of my yard quite steep and un-mowable with my ZTR. Here are pics of the area behind my shop and inside, where I am getting the water:

 

[patrick66]

Inside:

 

[bczygan]

The answer is obvious. Either raise the building or regrade, and regrading will be easier and cheaper.You need positive drainage away from the building and that will require the creation of a swale. The swale can lead to a lower elevation area for discharge, or you can create a french drain/retention pond.

For now I would create a mini swale. Clear all the vegetation and grass 3 or 4 feet around the building and slope grade 1/4"/FT min. down and away from the building in this area. Begin with the grade being at least 3'4" below top of slab elevation. This will eliminate ponding as a source.

This will also allow you to properly examine the wall to slab joint detail to see how it is performing.

You may be having a combination of too high grade, sheeting of rain down the wall and driven rain getting under the sill plate. You need to identify the individual problems and solve them.

Bill

 

[Radix2]

The answer is obvious. Either raise the building or regrade, and regrading will be easier and cheaper.You need positive drainage away from the building and that will require the creation of a swale. The swale can lead to a lower elevation area for discharge, or you can create a french drain/retention pond.

For now I would create a mini swale. Clear all the vegetation and grass 3 or 4 feet around the building and slope grade 1/4"/FT min. down and away from the building in this area. Begin with the grade being at least 3'4" below top of slab elevation. This will eliminate ponding as a source.

This will also allow you to properly examine the wall to slab joint detail to see how it is performing.

You may be having a combination of too high grade, sheeting of rain down the wall and driven rain getting under the sill plate. You need to identify the individual problems and solve them.

Bill

+1 you have a ton of space and there is no reason you can't regrade in gentle enough slopes to still be able to mow.

 

[pmiranda]

Regrading is the right answer, but to keep the slopes mild it will be alot of grass and topsoil to move and replace. For now, assuming the water is coming off the slope and not just from windblown rain or the roof dripline you could probably use 10 yards of plastic landscape edging to keep it out of the worst corner of the building. It'll only cost you 20 bucks and an hour or two to do and then you'll have a better idea of where the water is coming in.

 

[patrick66]

I've got a roll of that in the shop, good idea!

 

[jives]

After seeing the pics, it is no wonder you don't have more water. Dig out the soil around the building, put in a drain, and fill back with gravel. If there is nowhere to drain the water, you will need to make a drywell. Or, try these flat drain pipe like:

http://www.ads-pipe.com/en/product.asp?page=advanedge

Those downspouts are putting gallons of water right near the foundation. Put them in a drain to go around the building, or at least to where they can drain down hill.

 

[patrick66]

I'm actually amazed, too. Those two downspouts have actually helped to alleviate some of the problems I had before the gutters and downspouts were installed! We had very heavy rains back in May of '15 - over twenty inches over the month! - and there was very little flooding in that area. The vast majority of the water drains off along the back of the shop (towards that big puddle pictured) and around that corner of the shop, then off to the pasture. Some however, makes it from where those trees are towards that walk-in door area, and hence my water problem.

I dug back some dirt and grass from the area on either side of the walk-in door and heavily caulked those two spots. I found a couple of small spots along the back I had missed back in the Spring and hit those, too. We are supposed to have rain later in the week, so I'll see how that helps. Meanwhile, I've got plans now to lay a French drain along the entire back wall of the shop, and then around towards the pasture to the West. From what I've read here and on a couple of other threads concerning drain systems, I've got a good idea about what steps I want to take to remedy this issue once and for all. Thanks for the helpful suggestions! If you guys have other ideas that have worked in similar situations, I am all ears!

 

[rayra]

If you do use caulking, only caulk the outside seam / gap. If you do both outside and inside you'll just be trapping moisture where you don't want it an accelerating the decay of your angle iron.

Drain pipe holes should be DOWN at the area you are trying to collect water from. Otherwise water collects up to the diameter-height of your pipe. And UP or absent altogether in the sections where you are transporting the water.

 

[theoldwizard1]

.. I've got plans now to lay a French drain along the entire back wall of the shop, and then around towards the pasture to the West.

You want about 1" drop every 3-4' especially in the run away from the building.

Will it go to "daylight" or a dry well ? If going to daylight, you are still going you need some gravel on that area. Dry wells need a place to overflow.

 

[patrick66]

Thinking about a dry well. Where it would be, the overflow would not affect anything, and head off into the pasture.

 

[RickP]

You might also try some plastic trench drain in combination with the french drain pipe, especially around your door. We used micro channel drain by the door to our walk-out basement.

It's the kind that's installed around pools: