I am working on an elevated planter for the front of our house and am not sure of the best way to continue with the construction.
The planter is up against the house, the top will be 30 inches above grade, it's 12 feet wide, curved front, 28 inches maximum front to back. I plan on adding a stone veneer face and top. I have poured a concrete footer, 30 inches deep, 1/2 inch rebar reinforced; it's currently a few inches below soil level. I had to pour it in sections, so I plan to pour a continuous brick ledge for the stone veneer, and then pour sections of the planter itself above that (rebar reinforced).
My concern is having damp soil in the planter against the brick on the house, and I need some sort of barrier. My thoughts were to span the upper back of the planter with a heavy aluminum extrusion (No corrosion), and drape a pond liner over the aluminum, and at the foundation level, extend the liner horizontally away from the house to keep planter water from flowing down the basement wall/ soil boundary. Is this a good plan?
Or should I pour a concrete back wall to the planter, maybe tie it structurally to the curved front? Now that I think about it, maybe the weight of damp soil against the house will be too much for the wall to take.

 

I'm sure I'm missing something but I don't understand what type of drainage the planter will have in either scenario.

 

Thank you for responding-
The bottom of the planter is open to the existing soil, but I could place some drain holes on the curved wall above the brick ledge. My main concern is just a constant quantity of damp soil against the brick of the house, and now I realize that there also might be too much weight pressing against the house wall.
I have two pictures, but I haven't figured out how to put them in here.
Thanks again, Pulpo

 

Upload the pictures to photobucket & post the link.

 

Ok, here's the link:
Pictures by riscoe - Photobucket

 

Hey, that looks pretty good. There is a membrane that comes on a roll. You could put that between the dirt & the brick. Put the dirt against it about an inch below the top of the membrane. You'll hardly see it. Pitch the dirt on an angle away from the house. That's all you need.

 

Thanks for the input- I always wonder if I'm making the right decisions on projects like this, and would hate to damage our house not thinking things through.
I thought I might rough up the outer wood form with a wire brush grinder to give it some texture- would this be adequate for adhesion of the stone veneer?

 

I've never done stone veneer. I'll have to defer to someone else on that.

 

drainage mats adhere to masonry and include filter fabric so that your perimeter drains don't fill with topsoil, but that's probably expensive for the small planter we're talking about.

i'd use roofing tar, then stick 6 mil plastic to it. line the bottom of the planter with heavy-duty filter fabric. install weep holes slightly above grade.

make sure that you seal any weep holes on your house veneer.

you can try roughing up the form, but i think you'll want to scratch coat that wall after it's cured.

weight against the house will be minimal, unless that's a thin brick veneer. if it's standard bricks, it'll outlast us all and take way more abuse.

i'm guessing we can't see the brick/stone ledge in the picture?

in my opinion, you have a perfect footing for a structural brick planter. they're like concrete blocks, but smaller and made of clay. you could probably find a brick color very similar to your house.

 

Sleeper and Pulpo- thanks again for your help!
I had thought about laying up brick for the planter, but I am a woodworker who got into metalworking, and it's taken me years just to aquire the skills for those two interests. I'm a perfectionist by nature, so to learn bricklaying at the artisan level I'll require of myself- I just don't have time! (married and two young boys.)
I also bought a Stone mixer at a smokin' deal, and concrete is easy, so I think I'll just stick to the poured walls for now. I also want to integrate a stone look into the landscaping, and use the planter to visually attach the theme to the house.
The brick on the house looked like regular bricks (about 3-1/2 inches thick, with some holes in them) when they built it, so I assume it's not veneer, and will hold up to the dirt in the planter.
Will the roofing tar used to attach the plastic to the bricks also seal up the brick weep holes on the house? Or should I use something else? How expensive are the drainage mats you mentioned? I don't mind spending money if it's good in the long run. I only live with the price once, I live with the result forever!
Should the perimeter drains be small PVC tubes- maybe 3 or 4?
And yes, I have not poured the brick ledge yet- I wanted to get that in one pour so it is level and continuous.

 

perimeter drains are below the ground along your house, and they're basically a trench filled with rock to keep water from sitting there.

weep holes can be clear 3/8" tubing with a piece of cotton rope run through it to keep it from plugging. they should run through the form wall and all the way over the brick ledge just above grade. (you don't want water to be able to run into your planter, just out.)

i would seal the weep vents/tubes on your house with mortar or concrete/masonry caulk, then smear waterproofing over that. be thorough, and make sure that water from the planter can't get under or behind that brick and rot your woodframe.

i wouldn't worry about the mats. they might be difficult to find as well as expensive, and i think they come in massive quantity. just make sure you line the bottom of that planter with heavy-duty filter fabric. maybe ask in a lanscaping forum what's best. you don't want roots or dirt finding that perimeter drain.

and yeah, it's a veneer, just not a thin veneer like manufactured stone. they make "bricks" that are applied the same way. but you have the good stuff.

 

I see some structural problems in designs here.
Brick Veneer to Cladding Installation - - MTIdry.com

First lets re define some words here to grasp what a planter really is. Its a retaining wall not un like the ones that fall over or leaning. The brick veneer on your house is basically thick siding. It has little structural shear to it and no weight in pressure from above pinning it to the block below.

That being said. wichita_mech how would you feel on laying up 3 1/2" brick to hold the dirt.. How about a 4" block and a 3 1/2" brick veneer. You chose Crete and rebar and thats for goo reasons here. You structurally had it right adding the back wall also and tyeing it on the sides. Now there mass to mass and balanced weight to work right here.

Need to look at what thing really are hear. Weep holes in the planter is good in theory but won't amount to a thing yet.

If it freezes there, then their more design flaws here. Lets look at a planters exposure to water and freezing temps. Any planter against a facade like this should be consider a catch basin in a street. Turn the planter on its side and the facade above laying down becomes a sloped driveway emptying into the planter. The planter receives more rain and moisture then the ground away from it.

We water the planter to keep the dirt moist. Now we have rains adding to that. Winter freezes the dirt in the planter and it expands. Hits your concrete wall then when that stops the expansion in that direction the energy now heads to the house brick Not good.

I've been ripping planters out since the 70s because of what I mentioned above.

Seen to many basic design flaws. A planter needs to be addressed more in science. Too often its looked at as a raised dirt bed to put flowers and small shrubs in. Their lies the problem.

My designs on planters is this and is based on basic science.

bottom of planter is filled up with crushed stone. Right above the crushed stone hammer drill on the facade and the back wall. Some short 3/8 rebar pins. Pour 4" conc shelf on top of stone and slant to to front wall. There is where the weep holes need to be. After the Crete more crushed stone then fabric on top of stone. Hears the don't forget part. get a piece of ply. Hear is where the pain in the butt is buts very important. As you fill the dirt in also fill the back 3" of wall with crushed stone. and fabric in between the stone and dirt. to the top. Hers the science here. The heavier rain runoff from the facade hits the back vertical stone wall. That water runs to the concrete shelf. The shelfs slant directs that water to the weep holes through the crushed stone on the shelf. The stone is a two fold here in freezing. The back stone drains well and when the freezing dirt pushes in the planter the vertical crushed stone wall has cushion for the expansion. All the science's are working together.

If I were going to build your planter I would add the back inside wall for structural purposes. Keep it 4 to 6 inches below the dirt level. Also make sure its top is slanted into the planter. Above that grind out a brick bed joint 1/2 deep and bend the flashing 1/2 to fit in and down over the brick and then down over new back conc wall. caulk 1/2 " joint. Now you have a planter that will be there for a very long time.

This isn't out of a book its my 33 years of tearing old ones down and building new ones.

 

21boat has designed you a pretty fancy way to let water through the planter without letting it sit there. we don't get much freeze/thaw here in the pacific northwest, so i don't see a lot of its effects on masonry.

if you do build a backer wall, i would still remember to waterproof your existing veneer and make sure that your house's weep holes inside the planter can't let water in.

think you have enough room in there for that additional wall?

 

Sorry to all of the responders- I've been busy and haven't had time to respond myself.
To sleeper- Yes, we do get below freezing here in Wichita- I've measured as low as 0 degrees here, so it is definitely a design consideration on every outdoor project. We also average 30 inches of rain per year (we had 7 inches the other day!), some ice storms, a foot of snow, a tornado or two, but no hurricanes yet. I think I'll still have room for the rear wall though, and maybe two equadistantly spaced webs to tie the front wall to the back. I also think that insuring the water runoff from the face of the house moves through the planter and out the front will also contribute to reducing how often my sump pump runs when it rains.
To 21boat- I'll take every one of your points and incorporate them into the plan. My dad was an architect and a contractor, and if he were still alive, I think he would have advised the same thing. Water can cut canyons and fracture rock- you gotta respect it.
I still plan to build the remaining parts of the planter out of 4" cast re-enforced concrete. I have lots of 1/2" rebar and plenty of concrete materials. How should I configure the drains on the planter? They probably need to be more than just weep holes?

 

WOW you do get some rough weather. Being its 12 ft long I would put in no less then 5 weep holes. Since you get so much rain 3/4 PVC for weep holes. When you pour the inside slab angle the back up 4 inches. This will allow you to slope up the Crete 2 inches between each weep hole and yet still slope from the back to front.

You want it set up no matter where your pour water in that it will slope to a weep hole. It slopes from back and the same time slopes to weep holes. keep them right above grass line and don't clog them up with mowing grass. If they freeze up that means the planter is freezing up. The other reason for the crushed stone on top of the Crete and back wall to deal with expansion.

I'm glad you mentioned the 7" of rain. The left over PVC can be used for venting the planters crushed stone areas. Stub them in the back in the stone Crete level and bring the pipes up above planter finish grade.

Then get a reg 3/4 PVC 90 and a 'Street" 90. this will make an upside down U bend and act as a vent. The U will keep the vents from getting dirt and stuff in it. I would glue the first 90 so that can't be knocked off and dry fit the street 90 in case you want to clean out the "tip" as it were. in it. Now you are plumbed and vented for heavy rains.