Monolithic Slab Issue

[GT350RC]

I'm in the process of buidling a 26x26x9 Garage, with a 12x26 storage area in the truss. The pad is monlithic, and is "exactly" 26' x 26', however, it was purposely sloped from back to front (for water runoff). In hindsite, since this is going to be a garage for summer toys (two Mustangs), the sloping was a bad idea.

Now, I need advice. When I built the walls, all of my studs are plumb to the pad, which basically makes the side walls a trapezoid. Sheathing was installed level, in order to fall on a stud. I'm going to be using vinyl siding.

Here's my dilema: What do I do with the siding? If I install it plumb, the area where the siding goes into the soffit will show the slope. If I install it along the slope - the bottom will look sloped.

Anyone run into this, and if so what's the solution?

 

[GT350RC]

Never Mind - Isn't it funny how you answer your own question sometimes?

The siding HAS to follow the soffit/plates.

 

[Kevin54]

The siding HAS to follow the soffit/plates.

Exactly.

Now, I need advice. When I built the walls, all of my studs are plumb to the pad, which basically makes the side walls a trapezoid. Sheathing was installed level, in order to fall on a stud. I'm going to be using vinyl siding.

Is the top plate level or does the top plate run with the slab? I'm hoping you made it level and every stud is a different length. Then you run your starter strip for the siding level. That way it won't matter if the foundation under the siding looks like it slopes.

Kevin

 

[Junkman]

If you are going to be using vinyl siding, you start off holding it in line with the lower portion, and then you fudge about a 1/16" upward every row moving it toward "level" as you go up. By the time you get to the middle of the building, you should have enough fudge factor to make it look correct. Reverse these instructions if the roof has a tilt from front to rear or rear to front. With vinyl, you can fudge a lot if you take the time to work it out. Having a laser level sometimes will help you keep everything in line as you go around the building. I had a similar issue on my garage, where the foundation was not level. They were able to fix it so your eye didn't see it when the vinyl siding was installed. If it is very noticeable at the foundation level, then plant bushes along the foundation to hide the "defect".

 

[GT350RC]

Exactly.



Is the top plate level or does the top plate run with the slab? I'm hoping you made it level and every stud is a different length.
Kevin

ummm, no - I didn't cut every stud. The top plate follows the slab.

 

[GT350RC]

If it is very noticeable at the foundation level, then plant bushes along the foundation to hide the "defect".

Exactly. The lay-of-the-land is a downhill slope, so the garage actually rises from the ground towards the back. I'm thinking the grade along the foundation can be fudged so that it's not noticable.

 

[PAToyota]

ummm, no - I didn't cut every stud. The top plate follows the slab.

So you're saying the whole building slopes, but that the walls are plumb? Right?

Not exactly what I would have done, but it will work out. How much does it slope? Only issue would be if you tried to put a door in one of the sidewalls. Windows you could level out the top and bottom, but you'd have to build up the sill of a door opening...

 

[Junkman]

ummm, no - I didn't cut every stud. The top plate follows the slab.

If the roof isn't on yet, you can add a shimmed top plate to level the roof.

 

[Notch1988]

That's why ya do a curb and make it level...

 

[wilbilt]

If the roof isn't on yet, you can add a shimmed top plate to level the roof.

God, I hope so...

 

[GT350RC]

So you're saying the whole building slopes, but that the walls are plumb? Right?

Correct. I took the advice of the foundation contractor, who said this is done all the time.

 

[GT350RC]

If the roof isn't on yet, you can add a shimmed top plate to level the roof.

Too late - the trusses were installed a week and a half a go.

I do have some picks of the construction - just need to DL them from the camera.

 

[PAToyota]

Correct. I took the advice of the foundation contractor, who said this is done all the time.

Ummm... Not if you want it done properly...

If you're going to build the walls off the slab, the slab should be level. If the slab slopes, you either build a stem wall to put the walls on or form a level curb around the perimeter.

 

[kbs2244]

Lets think about this a bit.
If the whole slab slopes to the front, and he built square to the slab, so the front and back walls are not plumb.
(“Square” is at 90 degrees to something. In this case the slab. “Plumb” is a true vertical as done with a weighted plumb bob string)
He would have had to build trapezoid side walls to keep the back and front walls plumb.
And out of plumb walls are going to be a real problem with garage doors. If he puts a swinging man door in one of the side wall it is going to swing funny.
For the front wall, at the least, you need it plumb. Before you sheathe the walls you need to break into those side walls and get rid of some topside length so you can pull the top of the front wall back to plumb it.
A better thing would be to get some come-a-longs anchored at the base of the back wall and running up to the top of the front wall and rack the whole thing so that the walls are plumb. But before you do this, any sheathing, diagonal bracing, etc has to be broken loose. It is there to keep from happening what you are going to try and do. Once the thing is straight with the world, not your slab, then brace it.
But do either ASAP. The more work you do with as is the more you are just reinforcing the problem.
If you go with lap style sideling on the outside you can fudge each board a bit to hide any problems. But if are going to drywall or panel on the inside, bad words are going to be spoken. Nothing on those side wall will be square.
But the whole thing depends on how much of a slope there is. If it is 1 or 2 inches in 24 feet we can probably live with it as is. If it is 4 or 6 inches it has to be fixed.

 

[Junkman]

If he takes the side wall boards and bracing down, and attempts to pull it so it is level, then he runs the risk that the whole building might collapse. I hate to suggest this, but I think that the only way to fix this problem is to take it all apart, and fix it properly. I don't see any fudge factor that will be a long term solution.

 

[Kevin54]

Correct. I took the advice of the foundation contractor, who said this is done all the time.

He might do that all the time, but most of them that I know makes either the slab level, or if it has block wall or poured wall foundation, then the floor will slope but the walls are level. I say you are pretty much stuck with a building that looks like it runs downhill. And if it is close to another building that has lap siding it will only amplify the downhill look. Your siding willl have to run parallel with the top plate. If you cheat it, then the siding will look crooked with the eave. If you try to cheat the soffit to compensate for the downhill slope, you may get by with it somewhat. The only other quick soultion is to have some kind of siding that has vertical instead of horizontal lines in it. Maybe like a board and batten, or like T1-11. If there are only trusses up with no sheeting, I'm afraid I would biite the bullet and take the time to level up the top so all of the siding goes up properly. Hopefully you can find an easier solution though. How much drop did the contractor put into the slope? If it is 2" or more then you will really need good luck.

Kevin

 

[GT350RC]

Lets think about this a bit.
If the whole slab slopes to the front, and he built square to the slab, so the front and back walls are not plumb.
(“Square” is at 90 degrees to something. In this case the slab. “Plumb” is a true vertical as done with a weighted plumb bob string)
He would have had to build trapezoid side walls to keep the back and front walls plumb.

All of the walls are plumb.

 

[PAToyota]

Now, I need advice. When I built the walls, all of my studs are plumb to the pad, which basically makes the side walls a trapezoid.

Lets think about this a bit.
If the whole slab slopes to the front, and he built square to the slab, so the front and back walls are not plumb.
(“Square” is at 90 degrees to something. In this case the slab. “Plumb” is a true vertical as done with a weighted plumb bob string)
He would have had to build trapezoid side walls to keep the back and front walls plumb.

Yep, that is what he posted...

 

[Tman]

How much freakin slope are we talking?! it takes very little to drain and I doubt the concrete guy set his forms on a slope............sounds like the concrete guy needs a beating.

 

[GT350RC]

Ok - here's a finished pic of the garage, with a pad that slopes about 4" back to front. Can you tell?

 

[Charles (in GA)]

Thats alot of slope!!! I'll bet a car parked in there with no brake set and in neutral will roll right out the door.

Charles

 

[Willy Victor]

I think the building is square, it's just not plumb. If you drop a plumb line from the peak it will be further at the bottom than at the top depending on which way the slope runs or the bob could hit the building before it hits the ground, are you with me . It's hard to tell from the pics if it looks ok. I would have poured a curb level all the way around. My two cts.

Willy

 

[Northstar9126]

Maybe I'm just not seeing it right but those pictures don't make sense to me. Picture #1 is a free standing garage. Picture #2 is a free standing garage with house near by. Picture #3 garage is attatched to house. Picture #4 somebody stole the house.

 

[markb1]

I think the building is square, it's just not plumb. If you drop a plumb line from the peak it will be further at the bottom than at the top depending on which way the slope runs or the bob could hit the building before it hits the ground, are you with me . It's hard to tell from the pics if it looks ok. I would have poured a curb level all the way around. My two cts.

Willy

So if the slab slopes from back to front the garage is raked like a hot rod.

 

[george4]

Maybe I'm just not seeing it right but those pictures don't make sense to me. Picture #1 is a free standing garage. Picture #2 is a free standing garage with house near by. Picture #3 garage is attatched to house. Picture #4 somebody stole the house.

Not sure #3 is an attached house.

 

[Charles (in GA)]

Pic #1 was taken standing in front of the house, looking at the garage at a 45 degree angle from the front showing the man door, the house is to the photographers right side.

Pic #2 the photog walked directly across the front of the garage past it, and took the shot at a 45 degree angle to the front showing the other side of the garage and the wall with nothing in it. The house is well off from the garage as you can see.

Pic #3 the photog walked directly down the bare side of the garage and past it to the back, and took a pic 45 degree to the back or side, looking forward and to the house. The garage is not attached, its an optical illusion. If the house and garage were joined, the two roofs would be draining into a valley, bad plan. The garage just looks like it is attached. You can see some of the brick on the side of the house facing the garage. The dog followed the photog down the side.

Pic #4 is the last corner of the garage, at a 45 like the rest from behind the house, the house is directly to the photog's left just out of the pic.

Charles

 

[GT350RC]

Pic #1 was taken standing in front of the house, looking at the garage at a 45 degree angle from the front showing the man door, the house is to the photographers right side.

Pic #2 the photog walked directly across the front of the garage past it, and took the shot at a 45 degree angle to the front showing the other side of the garage and the wall with nothing in it. The house is well off from the garage as you can see.

Pic #3 the photog walked directly down the bare side of the garage and past it to the back, and took a pic 45 degree to the back or side, looking forward and to the house. The garage is not attached, its an optical illusion. If the house and garage were joined, the two roofs would be draining into a valley, bad plan. The garage just looks like it is attached. You can see some of the brick on the side of the house facing the garage. The dog followed the photog down the side.

Pic #4 is the last corner of the garage, at a 45 like the rest from behind the house, the house is directly to the photog's left just out of the pic.

Charles

Were you watching me?

 

[Charles (in GA)]

Were you watching me?

I was disguised as your dog............. woof! woof!

Charles

 

[GT350RC]

I think the building is square, it's just not plumb. If you drop a plumb line from the peak it will be further at the bottom than at the top depending on which way the slope runs or the bob could hit the building before it hits the ground, are you with me.

Nope - all of the walls are plumb, as mentioned in a previous post - and they're trapezoids to boot.

With the lay of the land, it's impossible to detect anything IMO.

More pics here (although there's a big gap in the progress)