engineered wall ?

Discussion in 'Hardscaping' started by STRINGALATION, Sep 3, 2007.


    STRINGALATION LawnSite Senior Member
    Posts: 777

    what makes a wall engineered and when is that required? and who engineers it? not to sound stupid just hearing tearms like geogrid and what not. any info is helpful but please know what your talking about. prefer responces from tthomass , mrusk, cgland and guys of similiar caliber. please no offence to any body i just hate conflicting answers
  2. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Posts: 333

    How about a long story short?
    These blocks are "pre-engineered"...thats why every F'n homeowner thinks they can build walls with SRW blocks. "Pre-engineered" up to a certain height that is, which is usually 4'. It all depends on the block manufacturer. Oh and a geotechnical engineer.
    NCMA Cert
    ICPI Cert
  3. tthomass

    tthomass LawnSite Gold Member
    from N. VA
    Posts: 3,497

    I have limited experience with engineers far as dealing directly with them. Typically such jobs are brought to me with the engineering already done.

    What happens is when a wall reaches 4' you should really have an understanding of what is taking place. An engineer will visit the site, study the conditions.....soil, slope, load etc.....then determine what the forces are that are being applied to the structure. A wall that goes 10' tall and is flat or even down hill behind it requires less engineerying/studying and strength then say a 10' wall with a 15% slope that raises final elevation another 10'. Such a wall would have much more of a load against it.

    Engineering is simply problen solving by someone who is certified. We, the contractor, may know what needs to be done BUT you always want to use an engineer. That way, if you follow their instructions the structure is supposed to have been built correctly and you limit your liability.

    Now build the same wall without an engineer, it fails and drops your customers brand spanking new Mercedes SL55 onto their neighbors Lexus below.....well you can see how that would go.
  4. mrusk

    mrusk LawnSite Gold Member
    Posts: 3,260

    Tthomas seemed to have summed it up well. Having a wall engineered is really not a big deal. Most cases it runs around 1 dollar per a face foot, atleast in my area.
  5. Grn Mtn

    Grn Mtn LawnSite Senior Member
    Posts: 863

    I got my NCMA (Level 1 SRW Installation) Certification for just the reason you discribed, and that is the main focus of course - when a wall engineer should be called in. tthomass spoke well, I'd just add that remember to include the buried block in the 4' statement.
  6. Mike33

    Mike33 LawnSite Bronze Member
    Posts: 1,649

    I agree with previous posts. How ever experience helps also. I biuld a lot of walls over 4' do i get eng. drawing, no. The reason is in my case local codes dont recquire and with my experience i am comforable. I have had my block rep out many times and they tell me the way im building them because im hell for over kill its fine. Now im not saying i no it all. I know the soils, compact base, install drainage, geogrid 80-100 % , more than double drain aggregate, cut swales above wall to take as much water away from wall. There are many times it is needed though a lot of commercial work and certain high resd. ones. i go that way. I just finshed one 8' contacted my rep they visited site and told me to build it. Also my company will supply an engineer if needed this is why i have faith in them. A couple miles from me at our new hospital a wall failed this summer that was engineered i had a thread on it. The wall was 20' high and i have more drain agg. and grid in 4' walls than they had in there 20' wall. I have also heard dont rely on enginers excepting resp. they can bale out and not always be liable.
  7. leaflandscape

    leaflandscape LawnSite Member
    Posts: 241

    I don't know if all stone companies proivide this service but Unilock has an engineering company called Risistone (, and they have a large number of construction details online and allow you to choose your desired heights, soils, etc., to help you engineer your project. It's a nice resource for estimating a project, but not necessarily a substitute for an actual engineer.
  8. forestfireguy

    forestfireguy LawnSite Senior Member
    from nj
    Posts: 601


    Who does your engineering at a dollar a face foot??? I had estimates from engineers that want min a grand to even look......We do lots of walls. some are engineered, most are not, I just spoke to an engineer in town last week about a 1000 Sq face ft wall, he said in order to start he'd need a partial topo survey and 2.50 a fcft. Partial survey 750 bucks, then 2500 in engineering fees, this was sight unseen, if he saw it he'd probably double his number it's a mess.......a poured in place retaining wall, I estimate age somewhere around 20-25 yrs, the wall has totally failed, drains are useless and it's actually been pushed over in spots by someenormus pines that were probably 8 ft tall when planted. It was doomed to fail from the begining, no footing to speak of, no drainage measure, well some pieces of iron pipe through it but no stone, It looks like maybe a 40K job give or take, with Demo and tree removals and such but sections of it are 7 feet tall and the property really does not allow much change from the existing heights, the HO told me"keep the engineers out of it, I don't want the building inspector around here" as walls over 4 ft require a permit. I said thanks but no, we have it engineered or you find someone else to have added to the lawsuit when it falls over and crushes your neighbors land rover.......some people......
  9. cgland

    cgland LawnSite Bronze Member
    Posts: 1,929

    Never listen to guys who say an engineered wall is anything over 4', because that is not the case. It all depends on the application, toe slope, surcharge or load bearing and a slew of other factors. You could have a 3' engineered wall or a 2' engineered wall. Also, just make sure whoever engineeres the wall is someone who specializes in SRW's. I called a geotech. eng. about a SRW and I knew more about them than he did!:hammerhead: Be careful, SRW's are a huge liability and if you bid them wrong it could take you under. There are a ton of associated costs that most do not think about like nuke tests, possible fencing sleeves, utilities, etc. Start with some smaller stuff and work your way up to the engineered stuff. You need to know your stuff (ie. soil types, compaction, grid placement do's and don't's, etc.) if you want to be profitable.


    STRINGALATION LawnSite Senior Member
    Posts: 777

    thanks alot pro's really do not plan on any real walls right now maybe a two level dry-stake for a border or raised bed. just trying to get my ducks in order SRW MEANS WHAT? ughh single row wall, solid reinforced wall i know i got the wall part right.

    glad and happy for the pleasant responces kinda in a funk right now i look to be cooking again this winter aaaaaaaaaaaaaaaaggggggggggggggggggggggggggghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh boo hoo boo hooo

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