In the coming months I’ll be building a lot of retaining wall around my home. There are many ways to do it and I’m hoping some of you will lend an experienced opinion to help me sort my options.
#1 I have been leaning toward poured concrete. Sons and I know what to do and have the tools. Drawbacks are that I would probably need to do extra excavation for a wide footer which would be buried behind the wall and under replaced fill ( lots of expanding soil). I’m not to fond of the look of bare poured concrete with plywood marks and form tie marks all across it. Thought about dyeing the concrete and using rough sawn boards for the face of the walls that will remain visible. Could parge. How well will it stick if I do?
#2 Retaining wall blocks of the type that have become so common. I haven’t used them before, but I have layed lots of block. They seem expensive at first glance, but I haven’t really costed out the comparison to poured concrete.
#3 CCA treated timbers. Yes, they’re readily available and I’ve built some sizeable walls with 6×6 and 6x8s. They are expensive.
#4 Used RR ties. I don’t care for the look much and I don’t want the smell too near the house, but they’re ok for some spots such as along an alley. They are hard on chainsaws and laborers. The material is about half the cost of CCA in my area.
#5 Innovation! I’m open to suggestion.
Thanks to all who share perspectives and comparisons.
I’m thankful for the loyal opposition! It’s hard to learn much from those who simply agree with you.
Replies
One possibility you haven't mentioned is masonry blocks or CMU.
Requires a poured concrete footing with rebar. The CMUs require horizontal and vertical rebar. Then all cells in the blocks are filled with concrete grout. Makes for a very solid & dureable wall.
An advantage is that masonry blocks come in a wide variety of attractive finishes and colors. Eg, split face blocks look nice IMHO.
Or you can use plain grey blocks and apply a brown coat & color coat of stucco, again many finishes and colors available.
These methods are popular in Calfiornia and the western states, don't know about where you are. Needless to say the wall may require a permit and engineering, if the walls are structural and required to hold back any signifcant mass of soil or hillside.
As I said, I've layed plenty of block. In this instance I've ruled out block due to the expansive soils. Maybe I've been too hasty. I agree that the split face blocks look good.
I'm in southern ColoradoI'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
Oops, I misunderstood! (or didn't read carefully enough).
When you said "Retaining wall blocks of the type that have become so common" I thought you meant the interlocking block units that don't get grouted or mortared together. Although I doubt they're rated for any structural purposes; mainly I've seen them use to hold back just 1-3 foot of soil.
And OOPS again. I did mean the interlocking blocks, but I was also noting that past experience at laying regular CMUs would lend itself to the occasion.
My general opinion is that, especially if there's much lateral pressure, a CMU wall with steel and grout is still not as strong and the comparable poured concrete wall. My soil is of a type that can exert massive lateral pressure when it's been dry and then gets soaked.
Timber retaining wall tend to float around a little and thus not show the movement.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
Hasbeen,
Those drystack retaining wall systems have been used up to 30' tall (engineered, you bet!) They make tieback systems for them. They also move like timber walls.
SamT
Although I doubt they're rated for any structural purposes
Depends on the block, and on the install. The stuff at teh big box is supposed to come with an instruction page that limits to 4-5 courses without engineering. As the engineers, and they'll tell you anything over two course & cap is just waiting to fail. As with most things, there's a medium in there.
I've seen the engineered block (it has a "t" shaped "handle" on the back) run up 20-24' tall. That has 6 sets of the geotech fabric and some geotech rebar, and many, many, many carefully compacted lifts of back fill behind it too.
The "trick" on a retaining wall is that it has to "look" like a poured concrete one in one shape or another (NPI). So, for CMU, it would nee the same footer as poured concrete. Driven or buried timbers are getting that "footer" though an effect similar to a moment arm (but it doesn't start kicking in until around 1/3:2/3 to 1/2:1/2.Occupational hazard of my occupation not being around (sorry Bubba)
What size will the walls be? How tall? My vote would be for the Large retaining wall blocks. Have done the others that you stated, The retaining wall blocks go up fast once you get the base (rock 1" ) & first course started. Will see if I can get some photos of the ones we have done in the past few years.
The tallest wall will be maybe seven feet high. The longest run will be no more than 50 feet.
I will need to be starting from a sloping bottom on some walls i.e. top will be level, but wall will be 3' high at one end and 7' high at the other. How do you deal with such a situation? I'll also need stairs in some places and a variety of curves, corners, and planters built in.
At o ne point my building inspector told me I needed to start retaining walls below frost. That seems unneccesary to me. What do you think?
Thanks for the input, Glenn.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
I've seen what G is talking about up at Castle Rock....
looks good and works well...
lot higher than 7' too...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Yeah, your walls have to have footings and yes they must be below the frost line.Regards,
Boris"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
What Cloud says. But maybe a bit more considering your skill level.
I've got a buddy with Boulderscape in San Juan Capistrano. They prepare the slope and spray shotcrete over the system, while sculpting, coloring, and adding stuff to the finished product to resemble naturally appearing rock. Stunning results. They build in planters, steps, whatever as part of the finished job.
I bet it'd be a lot like faux painting coupled with cake decorating techniques.
Have you seen the "Rock House" in So Laguna on Pacific Coast Hwy?
Yeah. Isn't that something?
Note the work done on the north side of PCH there in Dana Point. Where the exposed slope was just west of the hotel north of Del Obispo. My buddy did that work until the city cut them off midway thru the job.
But as far as proof of concept of this shotcrete working... Note the slopes south of Dana Point along PCH between San Clemente and Capo Beach. Years ago those were shotcreted and what are they? 100 feet high? Don't look real pretty, but it's kept those hills from falling.
Where to start, anything under 4' with block should be no problem, above 4' they (building dept) want an eng. to sign -off & permit. I my-self have done 6' walls under the radar (personal home). They have a fabric called Geo-grid, mesh that we use on any wall over 3' tall. Its a strong mesh that hold the wall in place. (will try to get you a photo) It is placed between courses, then back-filled to keep the wall from moving foward.
All you need is a 8-12" base of 3/4 stone to start on. You do not have to be below the frost line. The first course gets back-filled. We pay about $14 a ft for turn-key. I know you can get the block for $5 of less form the suppliers. Skip the Home/depot garden center type. You should be able to do it for $8 per ft or less.
For the price, the amount of labor & the look I feel its the best value on the market today. I do think there is a back issue of Fine Homebuilding that covers this subject.
My old house I think I install 300+ block by hand took all summer ,but ended up with a nice wall. In the same house I did some poured walls topped with stucco & poured in place lights for a hot tub area capped with fake stone on top (ledge). the two 8' walls were sweet but more time & $$$ then the block.
I will try to round up some more photos in the next few days. I would say we have used 50,000 or more of block walls in the past few years. Some of the new stuff is real nice almost looks like stone , but comes with a price!
Looks good. I think we will probably go the dry stack route with at least the part of our walls that are in our primary view.
When you need to change the level of the bottom course do you pack the gravel footing in for a sort of gravel step footing?
I assume that the walls you are building are in the Denver area and that local code accepts such walls without going to frost depth.
I am interested in the "fabric deadman". Is it actually tied to the block somehow or is it simply laid in? Might not last as long, but galv wire fencing would probably work until it rusted away.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
Thanks for all the input. I appreciate it.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
I have only built a small one, 30" at the max.But it was on very sloping land and there are 5 or 6 changes in the base.Start with picking a base level that is deep enough for the area that is lowested. You need to check the specs, but typically several inches of compacted base and one layer of block at is below ground. For higher walls it might be 1 1/2 or 2 courses.Then prepare that base and get it level and lay the first course. Keep going untill you are deep enough that you can go up one course level. Buid the base up untill it is flush with the top of 1st section. Getting that level with the first course is lots of work and trail and error. Once you get that level then you can start with the 2nd row over the 1st and then continue it over the step up. Then repeat for the next step up. After you get all of the base courses down then it goes fairly fast.I think that I spend a 1 1/2 days doing the base and 1/2 finishing it up.If you go to the manufactures sites lots of them have detailed specs and how and why you do things. Typically the geo fabric is laid between rows and then streched back in to the back fill. Here is one site and this is for one of there products.http://www.risistone.com/srw/romanpisa/design_r.phpYou can download the detaisl and drawings.But you probably want to start here.http://www.risistone.com/srw/Here is a Britsh company that does pavers and retaining walls. Have tons of details.http://www.pavingexpert.com/pavindex.htmHere are a couple of other companies that make the systems. Have not looked to see what details that they have on the web site.http://www.retainingwallstairs.com/
http://www.lock-load.com/Most of these are "designed systems" that are then licensced to local manufactures.So you need to see what brands are avaiable in your area.Look for concrete products, concrete materials, brick and stone materials.
Here is 2 more photos,
# 3 is a tall wall stepped back so we did not have to get a design on this one becauce each wall was under the ht. limit. The poured one is the one with lights & was finished with some extra top coat of Dry-vit finish. The wall is about 10 years old & still looks good.
Thanks again for your input.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
as some one already asked, how tall, long are these walls?
personally i like the dry laid stuff
there are lots of things used commercialy if there are tall wall i think look good.
more details please.
bobl Volo, non valeo
Baloney detecter
I'm not to fond of the look of bare poured concrete with plywood marks and form tie marks all across it. Thought about dyeing the concrete and using rough sawn boards for the face of the walls that will remain visible. Could parge. How well will it stick if I do?
I've done both successfully. If you want a taper to the face, place a nailer board inside your forms. One nail through each texture board will hold it in place. Best appearance is with uneven thicknesses of the texture boards. We used tinted concrete on that one and from 10' it still doesn't look like concrete.
Same job, my vibrator died on the last wall section, 8' tall. Rodded like crazy but ended up parging. Worked out fine, using the latex adhesive.
Here's an alternative that I know is available in your area:
PAHS Designer/Builder- Bury it!
Hasbeen .........Retaining wall blocks like the big box sells . I bought one (cheap huh) took it home looked at my old mortar mixer and and a stack of 2x12,s and 1x6,s and said I can do this . I made up a 16ft form used 3/8 rock, sand and mortar, revised the forms a couple of times and got a lot of satisfaction with unlimited possibilites. Neighbors stopped by and said "watcha doin" showed them and it was good times and a cold beer. Kind of get what you want feeling . A note of caution ,I'm the kind of guy that if I can buy it for a dollar I don't mind spending two dollars to do it myself , never did figure out the cost of a block , but our whole neighborhood is really shaping up.
Add spray-in-place walls. Shotcrete/gunnite. They can follow any shape, they can be finished nicely without worrying about a parge coat adhering, and if designed right, they can be pretty thin, which means less material. Can even get molds to create a pattern on them.
"Retaining wall blocks of the type that have become so common"
No, no, no, no, NO! Not one more landscaping project done with these godawful things! Might was well encase your house in vinyl siding, add some molded polystyrene shutters, and surround the whole place with some PVC fencing. : )
I'd second the poured concrete--likely your fastest, most cost-efficient option. There may be more actual work--footings and all--but a professional crew would be able to get it done in a heartbeat. The dyed concrete w. rough formwork you described is a nice look--we have a bank building by I.M. Pei constructed that way that's really beautiful. A simpler option would be to trowel on a coat of Surewall and finish with elastomeric paint.
Yes, Yes, Yes.If you start looking around at the modular blocks you will find that there are hundreds of different version.You can get then multiple modular sizes (1/2, 1, 2) or even ones with variale heights. You can get them with tumbled edges. You can get ones that you can ofset in and out so they are not all in the same plane.You can get blocks that contain low landscape lighting or patio speakers.You can get ones that stick out and have pockets to grow plants.Large amount of variables.I like the concept of the modular or CCA for your application as they can move a little as needed.If you go with the CCA make sure that they are ground contact certified and not "landscape timers". The landscape timbers don't have certified levels of treatment.I don't know what you have in terms of naterial materials.But stacked sized boulders will work. Ie, "farmers walls".And I have seen pictures of patterned concrete walls that look good.Don't know if want to get into the learning curve for something like that or not.http://www.concretenetwork.com/concrete/stamped_concrete_overlay_revamps_walls/index.html
I know this is not what you want to hear but it is outside the box -- old tires have been stacked up along old banks -- not pretty the first year but as the vegiation takes over they really fill in and look ok -- the other thought is just whole bags of concrete stacked up -- again takes sent time to fill in and weather but it is quick and easy -- just stagger them back on each course
"...there are hundreds of different version.You can get then multiple modular sizes (1/2, 1, 2) or even ones with variale heights. You can get them with tumbled edges. You can get ones that you can ofset in and out so they are not all in the same plane.You can get blocks that contain low landscape lighting or patio speakers.You can get ones that stick out and have pockets to grow plants."And they all look badly, obviously synthetic. Keep it in the subdivisions and away from my neighborhood.
I'm with you Tuffy, that stuff looks like sheeit! I think that in 20 years or so most of that stuff is going to end up in a landfill. Anybody considering that stuff ought to be beach slapped!Can you tell I'm a stonemason?So............why not build the retaining walls from stone? It would add value to the property.I've been asked many times to do fake stone veneer, and I realize that a lot of it looks good too............but.........I just can't bring myself to do it.Just my opinion, fwiw Rod
Tuff..........Well,well,well,well,well,................At least nobody suggested used railroad ties........hehe
In our area there are still relatively intact ties retaining walls that are at least 80 years old. They were used at mines all around here, the last of which closed in 1976. This is a very dry climate, BTW.I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
Hey, even seeing some more railroad ties in use would be nice for a change. I wouldn't even mind the precast concrete blocks so much if they were used in moderation. I just happen to live in a city where they're very, very, very popular. The concrete manufacturers must be on the city council, because there hasn't been a a civic improvement project in a decade that hasn't made extremely liberal use of those chunky tan blocks. They just rebuilt a street near me that now has 3' high keystone retaining walls stretching for two miles on both sides. I pray for ivy.
T......Railroad ties were used in a retainer wall in a small town near me . I checked them out yesterday and they were 41 runs high with a 2in set back on each run. I talked briefly with one of the street dept. guys and he said they had been there about 10yrs and were used ties when they got them. Another thing that I find interesting that older ties had a "date nail" in the exposed face, looked like a fat 1 1/2in roofing nail with two raised numbers on the head ,thus the year that it was first used.
As to retainer wall blocks I mentioned earlier ,using my own forms and pouring them my self I was able to get creative with different color dyes ,shapes and sizes. Some of them I put visqeen on the inside of the forms for a smooth shiny finish ,others I put pieces of scrap wood on the inside face of the form in the shape of a star etc., even tried leters as in initals,numbers as in house address's and some old fret wood I had laying around some of them went into a wash out land fill and the others are used as examples to bulid on future "brillant ideas"it took usually an hour in the evening and I got time to visit with the neighbors.
Gabion baskets......farily cheap, quick, and easy (well, sort of!).
I just used them this fall at my own house. Looks good in a "natural" setting.
Craig
#2....
Look into that deeply.... The commercial blocks will lock together and you can get some impressive heights outta them...
They are cost effective over CC walls...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
As everyone's talking about this, a caution is in order. Whether you hire an engineer or not, be certain of the wall's integrity. Ask me how I know. :-( We had a stacked boulder wall, "had" being the operative word. A hundred year rain (Frances and Ivan) took care of it, and it's costing me a saddening amount of money to fix. Anyway, the wall soaked up so much water that essentially it just separated itself from the planet Earth and slid. No real kickout and no topple over...just took this gravity thing a little too seriously.So now we've had a new solution engineered, we're using the specified geogrid, and foregoing the "we've always done it this way in the mountains" and the "seat of the pants engineering" solutions. Forewarned is forearmed. Or something like that...
I loved the idea of the old tires stacked and filled with gravel or sand. I my neighborhood, I think shopping carts, sofas, or old refridgerators would be the way to go.Seriously, my vote would be for CMU block wall with rebar and grouted. Attach some diamond lathe to the outside face and shoot gunnite or stucco; or attach faux brick or river rock to them. I'd probably waterproof the inside of them, have a french drain at the footing, and backfill the against them with lotsa gravel. At least in my neck of the woods, anything over 3 feet has to have plans and have an engineered wet stamp on them. These retaining walls have this habit of being under-engineered and simply blowing out when water hits them.Regards,
Boris"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
This gabion retain wall was 2 rows of 3' high baskets and 1 row of an 18" high basket. The base "course" was 48' long stepping back to about 30' long on top. In the end, I hope to make the wall twice as long as it is now.
I'm very interested in this and not familiar with it except for the occasional highway retaining wall.
What size rock is in the basket and where do you get the baskets? What is the wire guage and spacing?
Your place looks inviting!I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
The baskets are from Lane Enterprises. I talked with a local rep and picked them up at one of their plants in Carlisle, PA. The baskets consist of a 3"x3" grid of 11 ga. galvanized wire.
As far as the rock goes, I ended up ordering R-4 rock, which technically should range from 4"-6". Between the time that I ordered the rock and the time that it was delivered, we had gotten quite a bit of rain and PaDot came in and took most of the R-4's. What I ended up with was the "bottom of the pile" R-4's with some R-6's (6"-18") thrown in for good measure. The larger the rock, the harder it was to place them in the baskets. The next time I do it, I will probably try to use #4's (railroad ballast), which should be a pretty consistent 4" size.
Since I am an architect, I started the project with the vision of the wall being perfectly straight and level, but by the end after placing 50 ton of rock, I came to appreciate the more "natural" qualities of the wall.
Thanks for the compliment on the house. I've been putting off posting any pics because I thought that I didn't know how to post them. Now that that's figured out, I will try to get some posted soon.
I had a short (3') wall to build, so no engineering was needed. This was more $ than poured wall by about a third, but was better looking, and required no finishing (parging).
FWIW, I think a lot of the engineered stuff is ugly, but this mimics stone in way we like...
http://www.keystonewalls.com/pages/Contractor_pages/C_CM.html
PJ
Whatever you can do or dream you can,
Begin it
Boldness has genius, power, and magic in it. Goethe
"I'm not to fond of the look of bare poured concrete with plywood marks and form tie marks all across it. Thought about dyeing the concrete and using rough sawn boards for the face of the walls that will remain visible. Could parge."
How about using Hardiboard with adequate whalers for your formwork; leave it there for a vertical batten look. Paint to suit.
Here are some pics of a concrete wall, formed with foam form liners to make it look like stone. A bit of facadomy, but not a bad look when done carefully. I would stay away from parging a concrete wall.
If you ever travel I-90 accross Southern Minnesota, stop at a MNDOT Rest Stop that is just East of the intersection of I-90 and I-35. They used random width rough sawn boards on the insides of the forms for all the poured concrete walls, interior and exterior (if memory serves correct, anyway) and the effect, I think, is great.
Given your ability to do poured concrete, and provided you have a sawmill nearby to get the rough sawn, I would say it's a good option.
DW and sister DIY'd a 36" high wall on our place by dry-laying broken pieces of concrete left over from a slab demo. Broken sides exposed. Sounds strange, but the effect is pretty nice, price was right, and she likes the "green" solution.