DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Concrete, Stone & Masonry (http://www.diychatroom.com/f105/)
-   -   Slab for brick column.. What would you do? (http://www.diychatroom.com/f105/slab-brick-column-what-would-you-do-179679/)

no drain blues 05-15-2013 10:10 PM

Slab for brick column.. What would you do?
 
Hey guys,


Getting ready to have my brick mason set 2 brick columns (16x16) approx 5 feet tall. These columns will be on each side of a wide walk way approaching my house. Between the columns will be a metal gate. I have elected to pour the slabs, and hire out the masonry. The mason is tied up on another job and can't come by for input, until next week. So i figured i would try and get some feed back and brain storm before then.

The walk way is wide (66 inches), I want to avoid having an unusually wide gate, so I am thinking about having the columns set half way on the current walk way and half on a new slab (see pic). I will drill and have 1/2 inch rebar tieing these two pieces together. I plan on going 8-12 inches deep on the new slab, there are no frost issues here and seems most around here are going about 8 inches deep.

See any issues with this plan? Is there an issue going right to the joint between walk way slabs?

Also the current walk way is at least 50 years old and has very little settlement issues.

InspectorZo 05-16-2013 02:36 AM

Quote:

Originally Posted by no drain blues (Post 1180326)
Hey guys,


Getting ready to have my brick mason set 2 brick columns (16x16) approx 5 feet tall. These columns will be on each side of a wide walk way approaching my house. Between the columns will be a metal gate. I have elected to pour the slabs, and hire out the masonry. The mason is tied up on another job and can't come by for input, until next week. So i figured i would try and get some feed back and brain storm before then.

The walk way is wide (66 inches), I want to avoid having an unusually wide gate, so I am thinking about having the columns set half way on the current walk way and half on a new slab (see pic). I will drill and have 1/2 inch rebar tieing these two pieces together. I plan on going 8-12 inches deep on the new slab, there are no frost issues here and seems most around here are going about 8 inches deep.

See any issues with this plan? Is there an issue going right to the joint between walk way slabs?

Also the current walk way is at least 50 years old and has very little settlement issues.

Hey,
Where's the attached picture?

stadry 05-16-2013 04:31 AM

hired out the foundation work ? any competent diy-er's wife ,,,,,,,,,,,,,,,,,,,,, nevermind,,, so you want a 4" sidewalk supporting 1/2 the column & the other 1/2 supported by conc ' 8-12 inches deep ' ? ? ? is that what you have in mind ? that should be issue enough for anyone :yes:

it seems many times, we don't actually read what others write OR even what we write outselves,,, maybe there's a difference 'tween reading, comprehending, & ' really understanding ',,, communication is so difficult these daze :huh:

no drain blues 05-16-2013 08:11 AM

1 Attachment(s)
Had trouble attaching the picture earlier.

Basically, is it recommended to tie a footer into an existing slab and have the brick column 1/2 on an old slab and 1/2 on new? Or is this inviting settlement issues in the future?

Thanks!

Willie T 05-16-2013 08:51 AM

Why have it half on, and half off anything? If you have the room, keep it all off the sidewalk. Remember, this is going to be 750-800 pounds per column... and it could be more if you completely fill it with concrete and put a cap on top. Then you have the weight and torsional and rotational pressures of the gates. What do YOU think is going to happen to that little section of unsupported sidewalk?

no drain blues 05-16-2013 09:43 AM

I see your point Willie and those are my exact concerns.

The reason I want to do this is to minimize the distance between the columns and have a reasonable gate width.

Thanks for your input.

Willie T 05-16-2013 12:04 PM

Quote:

Originally Posted by no drain blues (Post 1180512)
I see your point Willie and those are my exact concerns.

The reason I want to do this is to minimize the distance between the columns and have a reasonable gate width.

Thanks for your input.

You COULD cleanly cut out a square about a 1/2" larger than the column will be, and dig out/pour a foundation. Then build the column all the way, directly from the surface of the foundation pad, up through the cut out hole.

But for looks, I would either keep the column all off the walkway, or all on (through) the walkway. I think half-and-half is going to look odd.

Of course, cutting a corner out like that is going to sacrifice the support the existing thickened edge now provides. But, no one will be driving close to that column, anyway, right?

InspectorZo 05-16-2013 12:39 PM

I agree with Willie. Half and Half doesn't even make sense in my coffee let alone in hardscape design. Also, spend the extra time and a little more money and make a footing for this column. It will be heavy and cause settlement issues in the future for you. Placing the weight of the column on the edge of a 4" (possibly unreinforced) concrete slab is not wise. It's like painting over a dirty wall...
When the settlement starts, it might create a trip hazard in your walk but more importantly it will immediately affect the operation of the gate.
I vote for footing under the column (12" or so deep matching the size of the column).
Good Luck! :thumbsup:

no drain blues 05-16-2013 06:28 PM

1 Attachment(s)
Thanks for info guys.

Going completely off the walkway does sound more robust. I can make up the additional width with a wider gate.

If I do go with a new footer, what are your thoughts on tying to existing walk with rebar? I have a rotary hammer, shouldn't be too big of an issue. Will this help minimize settlement or create more force against (and potentially cracking) the thinner walk?

Cross section view.

Fix'n it 05-16-2013 08:28 PM

looks to me that that column is doomed. the footing is nowhere near large enough. jmo

Msradell 05-16-2013 09:43 PM

The best solution may be to cut out a strip all the way across your sidewalk about 2' wide and make a continuous slab for the 2 columns. That would provide a much more stable foundation for the columns and the large area would certainly reduce or eliminate any settling issues. I wouldn't pin into the existing sidewalk. If anything, did start to move it would just crack the sidewalk anyway.

Willie T 05-16-2013 10:39 PM

That footing pad should be at least 30" square. No way should you make it only the size of the column.
Concrete's cheap. If it were me, the pad would be 36" x 36", and 12" thick... and it would have 4 # 5's going both directions.

no drain blues 05-16-2013 11:04 PM

Willie

If I go your method with a larger pad, I obviously don't want the entire footer all the way flush with current walkway etc. so that it's visible.

Should this be brought to a few inches from surface, then brick on the sunken footer so the first run of brick are "under ground" resting on the footer? Or, do two pours... one the larger sunken footer, then smaller (column size) footer on top to get flush with the height I want the first layer of brick to start?

GBrackins 05-16-2013 11:53 PM

you need to remove the top and subsoils which typically are not suitable for supporting structural loads. so obviously the bottom of the footing would be lower than what is shown in your photo.

lets run some rough numbers. brick column 16"x16" filled with concrete to anchor the brick and the gate.

1.33' (16"/12" per ft) x 5' high = 6.67 s.f. x 4 sides = 26.67 s.f. of brick x 40 psf (weight of brick) = 1066 lbs.

16" column width - width of brick on two sides (3" wide brick) leaves 10" for the concrete column

10" x 10" x 5' = 0.83' x 0.83' x 5' = 3.47 cu.ft of concrete x 150 lbs/cu ft = 520 lbs.

total weight = 1066 lbs. + 520 lbs = 1586 lbs. lets say your gate weighs 114 lbs to make things simpler then your total weight is 1700 lbs per column.

I'd recommend the footing extend a minimum of 4" beyond the column (16" column + 4" + 4" = 24") for stablility and support a 2'x2' footing covers 4 s.f.

1700 lbs / 4 s.f. = 425 psf. which your soil should be able to support as long as it's not disturbed or organic in nature. with your footing being lower than the bottom of the slab the footing can extend under the existing slab. Make sense? Now with me being a wimp I'd probably use Willie T's 30" x 30" footing because bigger is better and would provide lower psf and more stability, besides concrete is cheap.

in my area we'd have to extend the bottom of our footing til it was 48" below the adjacent grade for frost protection to prevent frost heave from toppling everything so consider yourself lucky being in Texas

no drain blues 05-17-2013 12:20 AM

Wow! Thanks for all the great info!

It makes sense to me when you say go under the current slab with the footing.

I'm I understanding you correctly: the finished height of the footer should be "below grade"? For example the surface of the footer should meet approximately the base of the current slab?

The first run of bricks will be below grade?


All times are GMT -5. The time now is 05:31 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved