Garage floods in the spring. Need advice

[Planenutz]

We bought this house about 3 years ago. The first year when the snow melted it flooded into the garage. Last year there wasn't as much snow and it was a gradual thaw so it almost flooded. Came close. This year we've been hit pretty hard with snow so I expect more flooding.
The problem is that the garage section on the left was added on to the original section on the right, and the slab top is barely above ground level.
There's a county road with ditch to the right of the garage (to the top of the overhead view) and there's a slope on the other side of the driveway.
The wedge shaped concrete pad is in front of the new section of garage. It heaves quite a bit in the winter. The other old slab doesn't heave as much. Why? How can I stop it from heaving if I tear it out and re-pour?

What would be best way to stop the annual flooding? (besides build new garage. Can't afford that)

Lay drain pipe around the garage? (The water gets deep on 3 sides of the garage; back, left, and front) How do you keep the drain pipe from freezing and not draining in the spring?

Cut a shallow depression across the driveway to the slope? I've been warned if I do this that it would make snow plowing difficult, but I intended to make the slope gradual. That still wouldn't drain the back and left side though.

Thoughts? Suggestions? HELP!

The soil is a sand and gravel mixture but when it's frozen it doesn't absorb anything naturally. I thought about draining it to the back, but the property line is actually at the treeline and neighbor isn't receptive to me putting the water on his land.

Thanks

 

[K'ledgeBldr]

Re-grade the area around the garage- regrade the drive to the garage.

The grade should be at least 6/10 (6" of fall on 10' of run) and the grade should start at least 8" below the top of the slab. Sheet flow is always better than narrowly directed flow- which usually creates erosion. If you can manage the grade there's no need for pipe- other than maybe piping downspouts (if you have them) out away from the structure about 10'.

 

[fiataccompli]

First, you need to know for certain where the flooding is coming from. Is it groundwater or surface water? People often recommend french drains & they do work, but they also need some area to drain towards so they have positive drainage. If you happen to have access to topographic mapping of your property, I'd think some folks here might have some helpful ideas. It's hard to get the full picture without looking all around you. If every direction you look from the flooding area is up, then...well, it was built too low & it will flood pretty much no matter what. But, even if that's the case, really looking around you, not just where it's flooding, but where the water is coming from is how you will find a solution (or find there is no reasonable solution). That does include the downspouts, gutters & any on-site drainage as mentioned above.

You can do some flood-proofing if the level of flooding is within reason. There are likely a number of DIY things you could do to at least reduce the damage incurred. I do this stuff for a living and work with people who are trying to stop issues like this all the time.

 

[Planenutz]

The closeness to the property line behind the garage is one thing, and its actually uphill going toward the left of the garage, It just happens to sit in a low spot.
If I re-graded the driveway, that wouldn't help behind the garage, would it? (I know zip about grading).
I believe its surface water but the garage is also always damp in the summer.

 

[greg13]

You say it gets deep, How deep is deep? An inch or two you may be able to build the floor up, a foot I doubt.

 

[Planenutz]

It gets about an inch deep, but the bottom of the walls (and everything inside the garage on the floor) gets wet. I'm worried the walls will rot, assuming they haven't already.
If it was just one section I would raise up the structure and the floor, but it was built at two different times and way too big for me to raise.

 

[Planenutz]

Did I mention this house was the home of a general contractor who now works for a large contractor that builds custom multi-million dollar homes?

 

[greg13]

It gets about an inch deep, but the bottom of the walls (and everything inside the garage on the floor) gets wet. I'm worried the walls will rot, assuming they haven't already.
If it was just one section I would raise up the structure and the floor, but it was built at two different times and way too big for me to raise.

I would consider figuring a way to pour an inch or two to the floor and try so grading around the outside. I would worry more about mold in the walls than rot.

 

[wssix99]

I think Planenutz must be related to Sparkynutz.

The answer here is obvious. Raise it! https://www.garagejournal.com/forum/showthread.php?t=371545

 

[Planenutz]

I think Planenutz must be related to Sparkynutz.

The answer here is obvious. Raise it! https://www.garagejournal.com/forum/showthread.php?t=371545

Nope, not related. But with the garage being 2 sections and 3 interior walls I don't think raising it will work for me.

 

[NUTTSGT]

Looking at the topo map, the property on the other side of the house/driveway is lower that around the garage.

I'd put some gutters on the garage and run the down spouts into some field tile. Rent a trencher, buy a roll of tile and provide the water a place to go.

 

[DGersic]

The closeness to the property line behind the garage is one thing, and its actually uphill going toward the left of the garage, It just happens to sit in a low spot.

If I re-graded the driveway, that wouldn't help behind the garage, would it? (I know zip about grading).

I believe its surface water but the garage is also always damp in the summer.

Water flows downhill. If you re-grade it, the water should flow away from the garage. Problem is, that area looks pretty flat, you don’t have a lot of choices on where to drain it to.

There’s a drainage ditch along the road. Can you drain your water in to that? If not by gravity, possibly with a sump pump. Is there a storm water sewer you could drain (or pump) in to?




Sent from my iPad using The Garage Journal mobile app

 

[K'ledgeBldr]

Did I mention this house was the home of a general contractor who now works for a large contractor that builds custom multi-million dollar homes?

K-
But he hired the cheapest electricians!!!

 

[Planenutz]

K-
But he hired the cheapest electricians!!!

He did the work himself.

 

[Planenutz]

Looking at the topo map, the property on the other side of the house/driveway is lower that around the garage.

I'd put some gutters on the garage and run the down spouts into some field tile. Rent a trencher, buy a roll of tile and provide the water a place to go.

Yep, draining to the other side of the driveway is one of my thoughts too and I know lack of gutters contributes to the problem, but with the area immediately surrounding the garage being lower than the rest of the area all the snow melt runs toward the garage on 3 sides.

Wouldn't drain tile freeze up and be plugged come spring?

 

[K'ledgeBldr]

That depends on the frostline-
If the pipe is below the frostline it ain't goin' freeze.

But seriously, no gutters and downspouts isn't your problem- you seriously have to consider re-grading. Sloping toward the road/culvert- anything else is just a band-aid at best.

 

[ShawnAM]

I don't have any suggestions about the water outside the garage. However, I put one of these on my garage threshold and it stopped water from coming inside the garage.

 

[theoldwizard1]

Lay drain pipe around the garage? (The water gets deep on 3 sides of the garage; back, left, and front) How do you keep the drain pipe from freezing and not draining in the spring?

Yep. Its called a French drain.

If you bury the pipe 2'-3' down, place 1'-2' of gravel above and 1' of gravel below it, it won't freeze. My French Drain and Dry Well Project. Just make sure there is proper pitch and the exit does not get blocked.

If the pipe is below the frostline it ain't goin' freeze.

The pipe itself does not have to be below the frost line, but the bottom of the trench before adding gravel would be best it it was that low.

 

[Innovate1]

French drains and dry wells only work if the ground water level is low and can easily be overwhelmed by heavy rains. I had a house where we were required to put in a dry well for gutters due to some construction additions. Clay soil and high water table - no basements in the area. There was an existing garage that was low and very flat ground lower than the street. We dug a dry well at the end of one of the driest summers and hit water at the bottom at about 12 feet. It rained before we got it covered and it filled up to ground level and took a few days to go down as I recall. Ended up putting in a pump. Also put in a street curb and sidewalk to keep street water from coming on the site (adjacent lots already had curbs. Were able to keep a slight depression around the garage and OHD to direct water away from the building so water didn't get in the garage. It should have never been built that low but were able to keep it dry by doing multiple things to help the situation.

It looks like you don't have much drop on the property but some. A french drain might work if the water table is low but keeping the inlets from freezing up could be a problem. It looks like the driveway in front of the garage may slope toward the garage - hard to tell exactly from the pictures. I suggest a slight swale around the garage and sloping to lower ground. A few inches of swale and drop will help a lot. If the pad in front of the OHD doesn't slope away from the building at least a little that will need to be removed and replaced with a slight swale. A slight swale shouldn't be a problem for snow clearing.

 

[Planenutz]

That's my concern about French drain is the topsoil and the drain are frozen until the snow cover is gone, but by then the snow melt has flooded the garage.
I am leaning toward a swale. Thanks

 

[cderalow]

trench drain across the front of the doors with the outlet dumping onto the far side of the garage into the lower elevation.

regrade the remaining 3 sides of the garage and a good door threshold under every door.

 

[Planenutz]

About a week ago I took the 316 out to plow the snow away from the garage sides. All was great.. until the next day when it warmed up and I had 2" of slushy water in the garage all the way to the back. :banghead:

Borrowed a submersible pump and drained down the low spots in front and on the side of the garage. Shop-vac'ed the shop interior.

Next day was a repeat. Got really frustrated and rented a gas saw and made a channel across part of the driveway apron and so far it's been doing good.

When the snow is gone and the ground is thawed I think I'll make a swale across the whole driveway and garage apron to the lower part of the yard.

Thanks everyone for your suggestions and help.

 

[WyGuy1]

Gutters would help, a lot of water dropping straight down as that snow melts. I’m having the same issue, previous owner only put gutters on 2 of the 4 sides of the garage...want to guess where I’m having water issues?

I’ll do a little grading work and install the remaining gutters and hopefully next year it will be dry.

 

[sennister]

Yeah I agree that gutters would help however..... We have a similar issue with our tuck under garage. The slope on the apron is completely flat at best or slightly toward the garage. Because of this when spring hits the snow melt drops right in front of the garage door which faces north. This starts to build up ice with refreeze cycles. It is very effective at building a wall so all water goes under the garage door and floods the garage. The good news is the rest of the basement must be a little higher because we never get water in there. We have gutters but they are Leafguard Gutters and with melt off, all the water just goes over them so they don't help at all. Well maybe I shouldn't say that because water is coming down the downspout so maybe it would be even worst without them. Our solution is we are building a new garage behind the house and closing off the garage to make it living space. To solve the water issue from run off we will use block for a portion of closing off the door and have a retaining wall in front of that sloped to push the water away from the house and the apron will be cut so we can have drainage into a french drain. You mentioned a french drain not being effective if the ground is frozen. This is partially true. Keep in mind that it if it is deep enough and course enough you will be fine. The frost may go down 4' but it goes down 4' of dirt,sand or rock. Just because it is course rock doesn't mean the frost will go deeper. Even if the rock is frozen water can pass. We just have to dig a french drain deeper up here in MN than most people.

An example of success with this is along my pole barn. Much like you the dirt was right up to the slab and ground on that side is higher than that so it is downhill to that wall. Picture a building built into the side of a hill. One spring I used the Front End Loader on my X585 to dig a trench about 1' deep and out about 2', I lined it and then used a drain tile that is 6" in diameter the full length of that wall and it discharges behind the building which slopes away. The trench was filled in with landscape river rock. It has a steel roof so all the snow stacks up on that side wall when it slides off. When it rains everything comes off on that side but I haven't had any problems with water coming under the wall since then. I do go through in the spring and move the snow away from the wall with either the snow blower or FEL on the X585. It depends on how hard packed the snow is from falling off and freezing and what attachment is on the tractor.

 

[Jazz1]

My friends garage is built at ground zero. Floods every spring and a small property so only so much area to disperse water. He has to raise garage 4”(never noticed this when he purchased house). Water won’t penetrate frozen ground. All efforts of moving water are in vain until the ground thaws

 

[sublime68charger]

So is your garage staying dry now?

 

[kbs2244]

Snow melt flows across the saturated top of the frozen ground.
So the swale is the way to go.
But properly routed gutters will slow the ground water saturation point.

 

[Planenutz]

So is your garage staying dry now?

I don't know yet. It was last spring that I cut the small trench in the driveway. This year will be interesting again. In the spring when road restrictions are off I have a concrete guy coming and going to do a small swale from the area that floods over toward the hill on the other side of the driveway. It's going to be wide enough that the snow plow won't get caught on it.
But before thats's done, I don't know if it will flood again this spring. Hopefully with the butchered cut I made in the driveway it will stop it.

 

[Planenutz]

Snow melt flows across the saturated top of the frozen ground.
So the swale is the way to go.
But properly routed gutters will slow the ground water saturation point.

Yeah, gutters are on my to-do list also. The 'properly routed' part is the question. Do I put the downspout on the left side of the garage, into the area that is already flooding- but away from the side of the garage by 4', or do I put a downspout between the 1st and 2nd stall doors (the split between the two sections and the transition between rooflines) that empties out into the driveway?

 

[kelpaso1]

From the looks of it you are plowing a bunch of the snow close to the garage judging by the huge mounds of snow. That's a big part of your problem. I would use a snowblower to get that snow far from the garage. And swales are the best for your less than adequate terrain grades.

 

[Planenutz]

From the looks of it you are plowing a bunch of the snow close to the garage judging by the huge mounds of snow. That's a big part of your problem. I would use a snowblower to get that snow far from the garage. And swales are the best for your less than adequate terrain grades.

That's actually just whats naturally fallen and pulled off the roof. I've been blowing all the snow away from the garage (behind me in the picture)