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.

rambler · May 11, 2004

I guess if you build a 24' slab then it will float ok, but if you build a 24' ring I don't see that holding up well enough to winter, it will crack. I suppose the whole slab or the ring with a full footer is about the same cost, eh? I'm not clear on how you plan it exactly, just a ring or a full slab. Most slabs have a 'rat wall' on the outside anyhow, or 1/2 a frost footer.

Sure would be a good place to forget the concrete entirely & use the blocks that interlock, they move a bit with the frost & work well.....

--->Paul

RalphVa · May 11, 2004

I've built 2 landscape walls, both about 2 pallets worth, here in central Va and in Baton Rouge. I only put in a base of about 1-2" of small pebbles and used those interlocking, mortarless blocks available at Lowes and Home Depot. They can be built in a circle, straight line or undulated line. The main thing is to kinda get them level from front-back. Side-to-side can go up and down a bit to follow ground contours. The interlocking tab on the back will cause the wall to lean about 1/2" per block as you go up the wall.

The walls I've built are around 2' tall. A developer just built a HUGE wall of them at the entrance to his new condos on route 20 coming into Charlottesville from the south. The north wall on the Lowes complex north of Charlottesville is built out of them. That wall is terraced. Each section is about 7'.

I've seen them used to build walls around highway overpasses. They generally cap them with a thick concrete top, probably to keep people from stealing them.

Ralph

SPIKER · May 11, 2004

I would go with the landscape blocks like others are saying, and NOT use any mortor in between, let the water run out and it will stay as well or better than the brick & mortor.

just my 2 cents worth, our local HD has them on sale for 1.59 or something like that each.

mark m /forums/images/graemlins/ooo.gif

AndyM · May 11, 2004

just my 2 cents worth, our local HD has them on sale for 1.59 or something like that each. 

Our Home Depot has them for $1.79.
A couple of Saturdays ago, they had them for $1.19 during a one day sale. I'm watching for that again, so I can buy a couple of pallets of them. A 60 cent savings adds up really quick!!!

ronjhall · May 12, 2004

Rob
I put in about 200' of Garden Wall last summer. The process is much easier than a brick wall. No mortar is needed.

When I moved into my home the previous owner had built a flower box out of bricks and mortar. Even though it had good drainage the bricks and mortar were breaking apart from Michigan's winter frost. /forums/images/graemlins/frown.gif

I tore all the bricks out and put in Railroad Ties. Last summer I removed the Ties and installed the Garden Wall. Some areas of the wall are 24" high. I used the glue that is recommended by the Garden Wall manufactures.
Here is a picture that I posted on another thread. Click Here
Home Depot sells the 12” garden wall blocks for 1.49 in SE Michigan.
I found a local landscape supply for $1.00 each. It pays to shop around. /forums/images/graemlins/grin.gif
I used some of the savings to have the blocks delivered. Each skid of 128 weighs about 3300 pounds. Delivery was $65 for 3 skids.

RobS · May 12, 2004

Thanks all for the input. I have built with the landscape blocks (Menards, $1.22. I bought 864 of the things this spring). They are easy to use and I like them for less formal areas. For our patio and the circle drive we are going for a very formal look, thus the mortared brick which will match the porch piers and the chimney. I'm pretty well convinced now to put my footers down below frost, it only adds about $200 in cement block and mortar (plus who knows yet how much of my time). This circular wall will be two wythes thick with a soldier course at the top and will have rebar in it. And yes, I'm planning on pre-running electric and water for the future fountain. I'll just have to use my backhoe that much more to get the footing in, darn that seat time. Thanks again for helping my brain get through this /forums/images/graemlins/smile.gif

timb · May 13, 2004

What about using concrete pilings (sonotube) set below your frost line and stationed around your circle (maybe every 45 degrees?) with a 'footing' poured as a grade beam sitting on the pilings?

Had a similar project idea that never went anywhere for other reasons but that was one solution I had considered.

Tim

RobS · May 13, 2004

Aack, Tim you're making me think too hard on this /forums/images/graemlins/crazy.gif

The sonotubes are an interesting idea, hmmm I could justify a post hole digger?

Had a discussion with the wife last night on summer schedule and project plans. Basically, our summer is filling up fast so I need to quickly get out of the planning phase and into the doing phase on this and the patio. I know once I get started things will just clip right along. As we say here at work... "It's time to shoot the engineer and put it into production" /forums/images/graemlins/smile.gif

Junkman · May 13, 2004

( What about using concrete pilings (sonotube) set below your frost line and stationed around your circle (maybe every 45 degrees?) with a 'footing' poured as a grade beam sitting on the pilings?

Had a similar project idea that never went anywhere for other reasons but that was one solution I had considered.

Tim )

I don't believe that this will work out because the attachment to the tubes isn't going to be that strong and the "ring" will just crack. Frost comes up from the bottom and lifts. The reason for the footing and the wall is that the frost can't grab hold of it and lift it. I had a large boulder, about 3' x 4' x4' heave under my driveway this past winter. The only thing that I can figure is that it has been moving up each year for the past 15 years. When we prepped for the driveway, we removed everything down 18" and filled with process gravel. It wasn't seen then, but it did break through the pavement this winter by forming a crown in the driveway. It is the power of frost that breaks ever thing.

timb · May 13, 2004

I think that there would have to be a sand/gravel bed under the grade beam/ring. I have seen this type of foundation construction shown for more normally shaped structures, but you may need more 'pilings' than are worthwhile to support the ring adequately.

On the other hand if you had a way to shape heavier rebar I'll bet you could theoretically create a strong enough ring that it would simply not likely break all by itself , it would only move enmass - but that again is probably more fuss than simply doing a normal continuous (and lighter duty) footer below the frostline.

Tim