C block construction question

[CJHeap]

I am drawing up the plans for my new shop / office and need some info on block construction and concrete footers.

I am replacing my 20 x 30 stick built typical garage with a garage apartment.

garage specs are 14 ft ceilings with cblock walls.

The second floor will be stick built with standard 8 ft ceilings .

Here is are questions:

I plan on leaving the existing slab but pouring a footer for the walls outside the perimeter What is a ball park size of footer needed for clay soils of east Texas ( again ball bark since an engineer will finalize the design)

What is the best method of using c block if it is going to support a second floor?

Are there any online material calculators ?

Thanks for the help. I have access to a idle crew from a friends biz at a song if I act quick.

[CJHeap]

someone has to know about block construction

[COMP]

i'm lurking for info myself

[MT4Runner]

Going scissor trusses? If the 2nd floor structure is 1' thick, and 8' walls upstairs, that leaves you 5' on the first floor below the office. :confused:

How do you leave the slab and have room to cast a footing that will be centered under the wall above? Do you plan to dig under the slab?

ASSuming you don't have any frost at your latitude, you probably aren't building a stem wall. I would guess that a 2'-0" wide x 10" thick footing would work--run (3) #4 bars about 2" up from the bottom of the footing. Rebar is critical in expansive clay soils.

If you were replacing the slab, I'd recommend subexcavating under the footings, add engineered fill 1.5-2' deep, a foot wider than the footing.

For the block, 8" commons should work. You'll need to solid grout the walls (at least in the office area) to support the floor load above. Plan on a vertical #4 or #5 bar every 24" (every 3rd cell) and a bond beam with another #4 or #5 every 4' or 6'.

You'll use 7.5 cy of grout for the solid grouted areas, and about 4 cy for the verticals/bond beams.

For 2' x 10" footers, you'll use 6.5 cy of concrete (order 8 for waste).


Do you have enforced local building codes? Why 20' x 30'?? 20' is narrow, and 30' isn't very deep. If you can, I'd highly recommend building larger now. If you're on a tight budget, but codes allow, I'd recommend building it 10' wider. 20' is just room enough for 2 cars next to each other, with no room to work on either. 30' wide gives you a lot of room to work on each, plus room in front. Go wide now, and then you could possibly add 20' more length in the future. (If you would add length to the back in the future, build in a reinforced area you can knock out later...if you add to the front, simply pull down your garage door, add on, then reinstall your garage door in a new front opening).

I have a 24' x 42' shop, including a 6' wide storage area up front. It's only 8' high, and is just perfect. If I had my "druthers", it would be wider, but I'm not complaining...but it's as small as I'd comfortably like.

Above the office floor, the block walls can probably be ungrouted--except for cells at vertical bar.

20' x 30' x 14' = 8,400 sf. Less a 10' x 12' OH door and two 3' x 7' man doors = 8,238 sf.

This will use 9,268 blocks, plus waste.

For the solid grouted area, if you're coming 15' off the back wall, you'll use

[CJHeap]

Going scissor trusses? If the 2nd floor structure is 1' thick, and 8' walls upstairs, that leaves you 5' on the first floor below the office. :confused:



No, I am building the block structure on the ground floor for the garage 14 ft ceiling.

On top of that, I will build the second floor with standard stick built ( or steel) so that I can reuse the existing hardi planked walls like pre fab units. .

The way I am going to leave the existing slab is that I want to go outside it with the perimeter footings for the block.

As for the size, that is what I am limited to. I live in Houston and that is all the room I have. I also need to leave 1 wall and the slab so I can call it a "renovation"

[threadkiller]

20' x 30' x 14' = 8,400 sf. Less a 10' x 12' OH door and two 3' x 7' man doors = 8,238 sf.

This will use 9,268 blocks, plus waste.

You may wanna check your math...

[CJHeap]

You may wanna check your math...

It is 1400 sq ft of walls without the doors subtracted. I am going to have 2 12 x12 doors so I can pull through and 1 man door. so that takes out about
5oo sq ft. .

The 8400 noted in the above post is a volume of a 20x30x14 cube.

[bigdreamin]

A block is 16"x8"x8" do the math. No where close to 9,000 block, maybe brick but not block. I get about 1500 block w/o subtracting for doors. An 80lb. bag of mortar will lay 40 block or core 3 courses. You'll need a Half ton of sand for every bag of mortar.

[bigdreamin]

It is 1400 sq ft of walls without the doors subtracted. I am going to have 2 12 x12 doors so I can pull through and 1 man door. so that takes out about
5oo sq ft. .

The 8400 noted in the above post is a volume of a 20x30x14 cube.

Not square footage, he's way off on estimating the block needed.

[MT4Runner]

No, I am building the block structure on the ground floor for the garage 14 ft ceiling.

On top of that, I will build the second floor with standard stick built ( or steel) so that I can reuse the existing hardi planked walls like pre fab units. .


Very cool!

The 8400 noted in the above post is a volume of a 20x30x14 cube.

Aww...Fuck! 2(20+30) x 14 = 1400.


MT4Runner = :shaking: