My garage always gets water into it when we have rain or a snow melt and I
was wondering what do to about it...
The contractor who poured our pad did not put any slope on it, so water just
comes in around the doors or from the car and sits on the floor instead of
running back out.
Also, the 2x6 walls don't appear to have any gasket material under the
bottom plate. The walls are still empty - no insulation or drywall over
them. Outside is sheathed and covered in vinyl siding.
The pad is 24'x32' and we've got three single doors on the north side.
Is there any way to keep the water from coming in the doors that won't
interfere with their operation?
Is having no gasket under the bottom plate a big issue or will sealing along
the inside seam with caulk take care of the small amounts of water we get in
under the walls? The pad is very close to ground level so it doesn't take
much snow for the melt to come under the walls. Rain isn't much of an issue.
Any suggestions are appreciated!
I know... They came recommended and weren't the lowest bid. It was like
pulling teeth just to find a contractor who was interested in the first
I'm just trying to make the best of the situation.
If you have any area to discharge to, cutting out a couple of inches in front of
the doors and installing a grate and drain may be your only reasonable option.
I take it the contractor isn't willing to try to "make it right"? Hard to
believe an competent contractor would argue that job has been done correctly.
Typically, you don't put any gasketing under the bottom plates, but they
*should* be PT wood if they're touching the concrete.
Is the site wet, as in ground water?
Are you heating the garage?
Was there visqueen put down below the slab?
Is there perimeter drainage?
Where do the gutter splashblock go?
How long ago was it poured?
There are many things that can make or keep a slab wet, most of them are not
Pacific Garages Inc.
An almost grade-level slab, and no perimeter masonry stub walls (usually
concrete block) under the frame walls? In other works, your garage is just
sitting on a flat slab? No wonder it is wet inside. Any blown rain will
come in right under wall, once felt or whatever fails. At a minimum, I'd dig
a slit trench around the outside, maybe a foot wide and deep, and fill it
with gravel, and provide a low spot if possible for water to drain to from
the trench. It could be oozing up right through slab- once it is wet,
nowhere for it to go downhill to. Other posters are right- design flaws
I know it wouldn't be practical, but if cost was no object, something like
this would piss me off enough to jack up garage and pour a proper sloped and
drained slab, with footings, under it, and then set garage back down. Garage
floors up here in the northland are poured after garage is built, and the
slab rests on ledge of the footings and/or foundation for the perimeter
wall. By local standards, what you have is a walled-in carport. Don't caulk
the inside of the sill plate- that will just keep the sills wet forever, and
even pressure-treated won't hold up under that. Do something on the outside
to keep water out.
I glued a strip of 2" x 1/2" wood on the floor and let the garage door
sit on it to get it aligned and to squeeze down the glue. The glue
should form a watertight seal. In anycase seal the seam with latex or
silicone caulk. That 1/2 in strip should form enough of a barrier to
keep the water from seeping in.
From what you described, I'd suggest the following. This does not of
course do a complete repair, but I would think replacing the whole
slab is out of the question.
#1. Caulk around all the walls, but ONLY on the outside. Use 100%
pure silicone only, not regular caulk. Personally, (assuming the
walls are attached to the floor with bolts embedded in the concrete
with nuts on top of the bottom plate), I'd loosen all the nuts about
1/2". Then drive a wedge under the walls from the inside (such as a
prybar). Lift the wall 1/8" to 1/4". Now go outside and fill that
gap with the silicone. Go back inside and remove the wedge and put in
another wedge about 4 feet away. IN OTHER WORDS, start at a corner
and use 2 wedges at a time, about 4 feet apart. Go outside and caulk
between those two wedges. Come back inside, leave the wedge that is 4
feet from the corner, but move the one on the corner 8 feet from the
corner, etc etc. Do this all the way around the garage, then
retighten all the nuts. You will end up with a good oozing bead of
silicone all the way around. and no water will seep in at the walls.
Be sure to also caulk whereever two 2x4 (or 2x6) plates meet to seal
the gap between them.
#2. The door problem will not be as easy. I'd put a rubber seal on
the bottom of each door but that dont stop the water completely. You
best solution would be to build some sort of awning/overhang above the
doors. That will stop most rain from hitting the door. As far as
snow melt, you are pretty much stuck, unless you use a concrete saw
and cut a section of concrete out in front of the doors and install a
grate, or repour the concrete with a dip all the way across.
#3 If there is an actual low spot in the floor, you could possibly cut
away a section of floor and put drain tile under it, with a sewer at
the lowest point. Run the drain tile out to lower point outside.
#4 If this dont do it, buy a wet and dry vacuum.
A bit unusual to pour a slab, meant for a building, not to be 6" above grade
for the finish surface at its lowest point. Read over your replies to
others. The slab is about 4 years old. Yet, the garage was built 1.5 years
ago. In the interim, between the garage slab and the garage building
erection, something may have happened. An overzealouz landscaper may have
added topsoil, and as a consequence, the lack of above ground clearance as
an example.. This is not the fault of the contractor who built the garage.
If the slab holds the same top surface to soil grade as when is was poured,
there may be a detail or two that the slab contractor and owner failed to
communicate to each other.
Slab sounds like a basic flat, level +/- 1/8". No provision for a car to
drive into, no downsloped apron. So, don't see any problem except that what
was allowed by the person who orginally contracted the slab.
#15 building felt is commonly used under the bottom (sill) plate before
erecting the walls. Gonna be fun trying to get that under there now.
Vinyl siding is loosely attached to walls. Was not meant to keep out water
in the form of melted snow pressed against the vinyl siding. Its needs a
continuous vapor barrier between the vinyl siding and the sheathing.
If you have any house wrap laying around, take a real close look at it. Its
woven plastic. Now, imagine water type hydraulic pressure from the side if
this housewrap is on the walls. Not hard to believe this water is seeping
The bottom of the outside wall "should" be at least 6" above the ground.
Otherwise you could end up with rot and/or water damage in the future.
Still, having said that, I've got a shed that sits about 4" above ground
and is still in perfect shape after 15 years.
The ideal option would be to jack up the garage, tear out the slab, and
repour a new one. But, that's a lot of work, and a lot of expense.
Second option might be to jack up the garage, and pour a small perimeter
wall around the perimeter (or mortar in a row of concrete block). Then add
a layer of sill sealer, and lower the garage back down. I'd apply a
waterproofer to the outside of the block wall to minimize water seepage.
The siding should also overlap the foundation by an inch or so. Any rain
that runs down the wall will drop off onto the ground and not follow the
bottom edge under the wall.
A cheap alternative would be to caulk on the OUTSIDE of the wall at that
gap. You don't want to trap water under the wall, so don't caulk on the
As for water that finds it's way into the garage from the cars, you could
try renting a concrete grinder and grinding a slight slope into the slab.
It might be easier to grind shallow "troughs" of sorts that would collect
the water and direct it out under the garage doors. I did something similar
on my own garage where the edge of the slab was higher than the sloped
floor. Water would pool right inside the garage doors. I used a 7" hand
grinder to bevel the front 8" or so, and haven't had any problems since.
You can rent large walk-behind grinders at most rental stores for big jobs
On the outside of the building, do anything you can to get the water away
from the garage. Slope the ground away from the garage, install a perimeter
drain system to direct the water away, etc. Obviously, good gutters will
help a lot if they drain out away from the garage.
As for the garage doors, they should have rubber seals on the bottom where
they contact the floor. Assuming this is the case and you still get
leakage, they do make rubber seals you can apply to the floor (search for
"garage door seal" on Google). The door comes down and sits on the seal and
any rain that makes it under the door gets directed out. The biggest
problem I see with these is any water that is in the garage (i.e. from the
cars) won't be able to drain out either.
If you get leakage around a walk-in entry door, you could add a storm door
on the outside. This will help protect the opening and direct water away
before it has a chance to seep in the door. You could also build a small
roof over the door to shield it from the weather.
I know this now... I've even considered digging around the garage and
pouring a footing around it... making the current floor a floating floor.
Still would need to find some way to seal this and joint between the current
slap and new "footing".
Not really a footing since nothing would be resting on top of it. Top would
be sloped to run water away from the building. Wood walls would still go
down to the slab though.
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