Hi All,
I am replacing my garage door with a wall and 36" wide steel door to make it a main entrance to the house in the winter and also into a workshop area.

It has been recommended that I pour a concrete slab across the front of the garage for the wall to sit on and have that slab just high enough to give an additional 2" drop to the driveway surface.

In very extreme rain or if snow/ice has built up to act as a channel and a heavy rain occurs then I can sometimes get water running up to the garage door and under. Since it only happens in extreme and unusual circumstances it is felt that the additional 2" slope should be plenty to prevent any more water problems.

My question though is that not only do I need a flat surface for the wall to sit on, I need the sloped surface to the driveway.

Is this easy to do all in one pour or should I first pour the slab for the wall then pour the slope once the first has set?
And if I pour in two stages should I keep a small separation between the wall slab and the slope or run them right together?

The house is on a hill so the front is level with the street and the back half is partially exposed and fully exposed only at the driveway side. The driveway dips down steeply continuing straight ahead and curving in toward the house so even though it angles a bit downward toward the house it is still sloping downhill as well so any water that comes down the drive will continue on down past the garage unless the force of the water is overwhelming gravity and the small existing slope just before the door.

Any recommendations on the concrete?

I have already cut the asphalt in front of the garage about 22" from the garage right to the peak of the existing slope. I will be ready to start pouring as soon as I finish repairs to the cinderblocks on the outside corner of the garage so any recommendations before I get started would be appreciated.

Thanks.

I don't know how wide your going with the 2" high slab but you can use a 2x3 which is 1 1/2 x 2 1/2. Use a full 2x3 on edge on the inside of the slab and then rip 1/8" off the outer 2x3 if the slab is under 12" wide (1/4" if over 12").
(or you can rip the 2x's 2" on the inner and 1 7/8" on the outer)

This will be enough for water to run of the exposed slab part. You will not notice the slope of the slab when installing the wall if you use foam sill seal under the bottom plate.

I dont know how wide your going with the 2" high slab but you can use a 2x3 which is 1 1/2 x 2 1/2. Use a full 2x3 on edge on the inside of the slab and then rip 1/8" off the outer 2x3 if the slab is under 12" wide (1/4" if over 12").
(or you can rip the 2x's 2" on the inner and 1 7/8" on the outer)

This will be enough for water to run of the exposed slab part. You will not notice the slope of the slab when installing the wall if you use foam sill seal under the bottom plate.

I have broken the project up into 3 pieces.
I needed a bit of fill from inside the garage to the outer edge of the cinderblock wall, a raised section for the new wall to sit on and the sloped section from the edge of the wall section to the driveway which is about 22" out from the garage.

I have poured the first section that goes out to the outer edge of the cinderblock.

My intention for the raised section for the wall is to go the full 8" depth of the cinderblock and approx 4-6" high. I still have to measure the height of the driveway vs the basement floor and will set the height of this section to 2" above the driveway level. I will use a concrete bonding agent to facilitate a strong bond to the previously poured section.

Finally I plan to pour the slope going from the raised wall section down to the driveway.
The point in the driveway where the concrete will end is the peak of a slight upward slope coming toward the garage that is high enough to stop water from reaching the garage under most circumstances and the additional 2" incline should prevent it in more unusual circumstances.

Entering the basement will be a small step down but there will not be a significant rise from the driveway going through the door.