Footings for Landscape Wall

RobS · May 11, 2004

I plan on building a brick wall about 18 inches high. It will be a full circle, 24 feet in diameter. The center will be a landscape bed, maybe with a fountain in the future. Brickwork will be clay brick, mortared in. My question is how much footing/foundation will this require? I plan on pouring a footing but does it need to be below frost line or can I keep it just below grade?

/forums/images/graemlins/smile.gif

chucko · May 11, 2004

( does it need to be below frost line )

if it does not go below the frost line then even doing it would be a waste of time and $

RobS · May 11, 2004

if it does not go below the frost line then even doing it would be a waste of time and $ 

That's what I tend to think but what about the miles of highway, sidewalks, driveways built every day at grade level? My foundation will support very little weight, obviously not structural. It seems if my footer is strong (with rebar), the whole thing could float with freeze/thaw, like a driveway.

I've got the project designed and costed with a footer below frost, I just want to make sure I'm not overkilling it too much /forums/images/graemlins/smile.gif

dummy · May 11, 2004

I plan on building a brick wall about 18 inches high. IMO The weight of the wall itself would probably handle the freeze/thaw cycles, but what about the amount of material behind the wall ? Would be a shame to have to do it twice. Chipping mortar off of brick is less fun than laying the block for footers. Besides, everything else your doing looks great. Why skimp now? P.S. Don't forget to lay conduits in the footers for lighting, fountain, water, etc. Another thing that's not fun to do after the fact.

CTyler · May 11, 2004

For a landscape wall I'd say no you don't need a footer. Landscape walls have several inches of packed rock to set the block onto. Sand can be placed on top of the packed base to help in final leveling. Typically an inch or less. The first course is buried at ground level as well.

Thats for a Landscape wall(not mortered) however is sounds as if you want to build an actuall brick wall. I would call a couple masons in your area and see what they recommend.

ChrisJ · May 11, 2004

Being in Michigan I'm sure your frost is as bad as it is in New Hampshire. I've built plenty of garages on alaskan slabs, these will float in the frost. As long as you create a decent footing and put some rebar in it, it should stay together as a single unit. The rebar is the key as it will tie everything together. You can pick up #4 rebar just about anywhere and it's easy to bend. You may also want to run verticle rebar out of the footing to tie the wall in as well, this will help when you fill the area with earth. It will prevent future problems with your masonry wall.

Good luck.

PaulT · May 11, 2004

Never having actually done what you are planning, I am not really qualified to give an answer. Having lived in Upstate NY most of my life, I do have an opinion, though. With a circle as large as you want (24ft), I think what you will face is heaving in different places. The wall will crack at several points, and it will shift up/down/sideways at different rates, depending on where the water/ice lenses are underneath it. With a rebar slab, the slab is strong enough to stay flat and rigid, so that the whole thing floats on only a few localized ice lenses. I would think that you could not (cost effectively) get enough strength into the brick/mortar circle to float as a whole. The only way to get the whole thing stable is to prevent float, and that requires a footer below the frost line.

chucko · May 11, 2004

Ok I live a little south for frost to be a problem but I do know about building.
A floating slab will do just that a footer will not. What if the footer cracks? What will that do the the brick and/or block on top of it? The floating slab has rebar in it in this pattern # a footer will be like this =

how deep is the frost line up there? How much more work would it be?

Currmudgeon · May 11, 2004

18 inches is too high for a single wythe brick wall. The weight isn't there. You might think of retaining wall blocks. They do have the weight and lean back, just a little for stability. At 18 inches, these should be OK without the soil reinforcement grid used for taller walls.

Most segmental concrete retaining walls are laid on a bed of compacted aggregate, so no concrete footing is needed. They work a bit with the ground, depending on how frost active your soil is.

Do a web search on segmental retaining walls. The trade names Unilock, Anchor Wall, Rockwood, and StoneWall Select come to mind. Most of their websites have detailed drawings showing how they should be installed.

Currmudgeon · May 11, 2004

( As long as you create a decent footing and put some rebar in it, it should stay together as a single unit. )

That should work. I would add a ring of No 4 bar under the top course of masonry to hold the whole thing together.

Place a few inches of open draining stone at ground level, and leave weep holes in the masonry so the thing doesn't turn into a bathtub and freeze crack. Not to mention drowning your plantings.