Any concrete / excavating people here?

[trapper_canada]

I want to get a garage built and the guy came to build a grage pad for me but said there is so much of a slope/grade change that the only way he could build it is to make a stupidly high footing or to have a grade beam used. Grade Beam is way too much money.


Can't I just get a bunch of fill brought in to level the spot? I imagine there are issues with that settling? Can it be packed with a packing machine or something?

It is approx 24" from high to low.

Thoughts anyone?

[MarkRobinson]

grade beam shouldn't be too much more money: it's just a perimeter beam under ground, typically (for some residential & light commercial construction), 12" wide by 24" deep with #3 or 4 steel rebar stirrups and #4 or5 continous bar, usually 4 running the length of the beam. Typical house foundations have grade beams and intermediate grade beams under load bearing walls and at certain distance intervals.

"select fill" ie, selected fill (Limestone/cliche) material that compacts to 90-90% in 6" layers at a time until your grade is met.

What about cutting into the grade & having a slight retaining wall around the cut area, so you dont need to cut as deep.

[dad911]

Best way is to have a footing all the way around, below the frost line.

24" isn't too much, if you build it like a pole barn, you can get the 'poles' down to virgin ground, level a pad, and compact the fill in between. It should really be brought in and compacted in "lifts" of 8-12" at a time with a vibratory roller.

[trapper_canada]

Originally Posted by MarkRobinson

grade beam shouldn't be too much more money:

I only spoke with one company... they said (and I am still trying to get my digestion back) $10,000 for the grade beam plus $4600 for 17 piles plus the actual pad on top of that.

[mudman]

There are several ways to get around your problem, 24" isn't too bad.

Bringing in fill to make up grade isn't as straight forward as some would think. The volume of fill required can be very deceiving though when you consider where grade has to be blended to outside of the building's perimeter.

Compaction is very important even if you're not raising grade like you want to do. In some situations I'll spec compaction @ 2" lifts which can really slow down grade/base/prep and make it tough logistically when you're talking about receiving fill 40 yards per load. I have no problem paying for a couple more delivery charges and receiving smaller loads if it helps me not have to deal with a pile on site. ie you need 60 cuyds total, that's at least 2 deliveries anyway, I'll set up for 4 deliveries of 15 cuyds. That also means a smaller/lighter truck on your site and better chance you can have it dumped in a good location.

[mudman]

Originally Posted by dad911

...with a vibratory roller.

A plate compactor would be recomended for a garage build... fits in the footing trench, PSI is just fine, and with tighter boundries in a garage makes for better compaction patterns.

[dad911]

Originally Posted by mudman

A plate compactor would be recomended for a garage build... fits in the footing trench, PSI is just fine, and with tighter boundries in a garage makes for better compaction patterns.

I would never compact below footings. Ok, not never, rarely, but only if compaction was tested by an engineer. When you add the costs of compaction & testing, frankly it's typically cheaper to just make the footings thicker or the walls taller.

I said (meant?) if it was built like a pole barn, with PT poles to virgin, the soil/fill in between could be brought up in lifts and compacted.

[john70t]

Any type of fill will eventually shift/flow to a lower spot without a retaining wall.
That retaining wall, like any footing, needs to sit below the frost line(typically 48") and be thick enough to resist lateral forces.

Watch the Canadian t.v. series "Holmes on Homes" a few times, and see how difficult it is to fix all these details once they're built. The building inspector and contractor licensing can sometimes be your friend.

[RWebb]

based on my neighbor's experience with a $10,000 extra cost, I think you are right to get some alternatives lined up beforehand

you might figure out who is a good structural engineer to talk to in your area of Sasquachewan

also, do you have a pic of the site?

[mudman]

My note on compacting footing trench is situation specific, and I guess I only have done that when somebody has gone too deep or I'm basing the footings (unconventional but I like to do this).

Trying to respond to this has made me consider how difficult it would be for me to contract this out, and I know what I'm doing! If you find a company that'll do it right without your guidance you'll probably be paying substatially more than your low bid. At least thats my experience in my area.

[trapper_canada]

Originally Posted by RWebb

based on my neighbor's experience with a $10,000 extra

also, do you have a pic of the site?

Here you go. Doesn't seem bad that bad...the right side is the low part and the front right the lowest. The orange rope is the outline of where I was hoping to have the garage.

[mudman]

Biggest concern I would have if this was my project would be how this would affect drainage and how paved surfaces/driveways would interact. I see no big deal here as far as grade is concerned, maybe I'm missing something?

[trapper_canada]

Originally Posted by mudman

Biggest concern I would have if this was my project would be how this would affect drainage and how paved surfaces/driveways would interact. I see no big deal here as far as grade is concerned, maybe I'm missing something?

I posted this cause I thought I was missing something too

[GWN7]

This garage pad looks to be about 22' X 24' Your going to have to remove 6"-8" of topsoil and fill that to keep your grade correct and then fill to level the base.

Check with the city to see what their requirements are for the size of pad your planning to build before you start looking for a contractor.

[trapper_canada]

Originally Posted by GWN7

This garage pad looks to be about 22' X 24' Your going to have to remove 6"-8" of topsoil and fill that to keep your grade correct and then fill to level the base.

Check with the city to see what their requirements are for the size of pad your planning to build before you start looking for a contractor.

It is actually 20' x 30' (hard to tell from the angles). I am outside the city and have the permit already...very flexible with what I want to do.

I think it is going to be a combination of soil removal, building up, and putting in a thicker/higher footing. Also looks like it will have to be put off until Spring...too many decisions need to be made (might change the spot for garage all together and put it at back of lot) and I don't want to rush into it.

[GWN7]

I had two buddies build garages this year. On average they saved $3k by buying their materials from Menards. If your around Regina the closest store woud be in Minot, ND

[A930Rocket]

Where is the driveway/garage entrance? If it's the side closest to the camera, I'd be inclined to cut into the grade towards the back, pour footers, block as needed to retain the grade and pour the slab. You'll gave to determine what grade your slab is at and use 12" block to that point. The garage slab is 4" thick on the 12" block. Use 8" block above the slab to retain the dirt as needed (left side and rear).

If the entrance is to the rear, just pour your footers, block to the correct height, backfill and pour your slab on the 8" header block ledge. You can fill the block cells at the same time you pour the slab.

Don't forget to design in that sissor lift recess or two post reinforcement!

Waterproof the outside and use a drain to the low sides.

[whiskyb]

If you are buying pre made trusses, price the difference between conventional and cathedral. I was able to get cathedral for little more and it gives way more ceiling height

[Porsche-O-Phile]

+1 to the above - grade beam shouldn't be that much more expensive.

It's a residential garage for crying out loud - you should be able to level it out with gravel and pour level on top of it.

$10k?!?! Sounds like they're being highly unimaginitive in their approach to solving this and don't particularly care, since they can just stick you with a big bill for it.

Ideally foundation should extend down below the frost line as has been said, although I've seen plenty of residential garage slabs-on-grade even in this climate that last just fine. If you've got adequate drainage underneath and no opportunity for water to get under there and freeze/heave, you'll probably be okay.