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View Full Version : How do you guys keep your walls perfectly straight?


cards1
01-06-2009, 11:52 AM
I have done roughly 30 walls to date and i'm still looking for an easier method to this problem.
Scenario is your building a wall a 100' long. How do you guys keep that wall perfectly straight?(Keystone and versa-lok)

We use the twine method which works great but it can be a pain dealing with the line in your way everytime you set a block, plus it takes alittle longer!

Marcos
01-06-2009, 11:57 AM
How do you guys keep that wall perfectly straight?



Hmmm...
Never heard of a gay wall.

cards1
01-06-2009, 12:19 PM
Hmmm...
Never heard of a gay wall.

Sorry Marcos i owe you an apology i didn't mean to peek your interest on the whole "gay" vision i gave you but this is a landscaping website not the guy on guy website you have bookmarked!

richallseasons
01-06-2009, 02:47 PM
I think that what you are doing is it, string line every time. What else can you do?

mikeny
01-06-2009, 05:05 PM
I use a large framing square as well as a string line, drop the square over the top as long as that is level you get the true 90 degree for a straight face.

CertPro
01-06-2009, 07:53 PM
When I install walls, I get my base stone perfect, then I screed 1" of sand, then I snap a chalk line in the sand and follow that.

DVS Hardscaper
01-06-2009, 08:24 PM
How do you guys keep that wall perfectly straight?


I usually try to make sure that we don't put any dresses, high heels, or make up on them.

Bru75
01-06-2009, 08:28 PM
Stringline for short walls, single dot laser and a builders square for the long ones. I have a line laser that I thought would work for this, but it turned out to be to hard to see in sunlight.

steve5966
01-06-2009, 09:07 PM
Use a 4' level or straight board. After you get a few blocks in just slide it along the back of the blocks or keep using the string. Either way works good.

zedosix
01-06-2009, 09:09 PM
We pull a string for long runs then follow it with a chalk line every 20 feet or so. If you use string, make sure you leave a small gap between the string and the block. If your blocks touch the string it just moves out and you end up with a crooked wall. For brick, screed sand, for walls, screed stone dust.

CertPro
01-06-2009, 11:06 PM
Zedosix - What is your thought process for switching between the two setting medium? I thought stone dust was a major no no

zedosix
01-06-2009, 11:33 PM
Zedosix - What is your thought process for switching between the two setting medium? I thought stone dust was a major no no

I should call that stone screenings, not stone dust. I like to use stone screenings because it will pack harder and stay in place whereas sand will wash out with time.
We use sand as a bedding layer for pavers because we want our brick to sink in when compacted, we want that sand to pull up into the brick joints and lock together as one unit. We then use restraint edging to hold the laying field in place. Now with a retaining wall we have one straight row of block, if we set that on an inch of sand there really is nothing to prevent the blocks from moving forward or sinking unevenly into the sand. A retaining wall usually has some amount of water directed to the base as well, and the sand will likely wash out over time faster than stone screenings.
When our co. installs walls, we always bury one row (laid on screenings) and on the second row up we put a restraint edge.

Hard at Werk
01-07-2009, 12:17 AM
When we put up a wall we put in a base of at least 8" of crushed 3/4 stone depending on soil, water buildup etc.. level the stone using a laser as if i were to lay on it and then pack it like crazy. Then put about a half to three quarter inch of 1/4 stone (small clean stone no dust), and lay on that fine stone adding or subtracting 1/4 stone. Backfill with 3/4 clean stone ( NO GRAVEL !!!) at least a foot (depending on soil, height, water etc...). :weightlifter:

CertPro
01-07-2009, 09:06 AM
But doesn't the excessive amount of fines in screenings promote uneven settlement over time? Not to mention the breakdown of the screenings themselves.

zedosix
01-07-2009, 09:16 AM
But doesn't the excessive amount of fines in screenings promote uneven settlement over time? Not to mention the breakdown of the screenings themselves.

Guess that depends on how much you are using. We screed our granular to within 1/2" or less then add just enough screenings to level our base. How is this going to become uneven if our base is compacted and leveled first. Don't forget in a vehicular application (pavers) we have cars, trucks pedestrian travel, salt etc, this is where we can see a breakdown of stone dust. Not on a retaining wall, you lay the block it stays put. With sand all I am saying is it just moves to much with the initial laying of the base block, I'm sure if there was only 1/2" of sand and all methods of srw construction were practised, it would likely stand the test of time as well as stone dust.

ford550
01-07-2009, 03:36 PM
NCMA allows screenings or sand to be used in retaining wall installations, they have indicated that either one is acceptable. Paver installations, screenings is not acceptable only concrete sand.

STL Ponds and Waterfalls
01-07-2009, 08:14 PM
NCMA allows screenings or sand to be used in retaining wall installations, they have indicated that either one is acceptable. Paver installations, screenings is not acceptable only concrete sand.

NCMA does spec up to 1" of course sand for SRW setting base, but I prefer 1/8" stone with dust. I tried the sand on one small seating wall and the jury will be out on that one for awhile. Screenings once setup after install is like concrete (but flexible)! I'm still worried about sand washing out, but if your base is setup right that shouldn't be an issue. Unless your setting in a thick bed of sand. If you screed your base in the first place you shouldn't need a setting bed, but that's in a perfect world.

Hard at Werk
01-08-2009, 11:51 AM
That's why we use fine crushed stone almost like a peastone but more angular. What it is that this stone is considered to be trap rock, just fine trap rock. Very easy to work with and there is no dust variable that will hold moisture or settle as much as screenings. It's clean and sizes range from about 1/8 to 1/4 . Even if NCMA does allow for use of concrete sand, I don't like it because its round and tends to move more and wash faster than trap rock.

AztlanLC
01-08-2009, 01:54 PM
That's why we use fine crushed stone almost like a peastone but more angular. What it is that this stone is considered to be trap rock, just fine trap rock. Very easy to work with and there is no dust variable that will hold moisture or settle as much as screenings. It's clean and sizes range from about 1/8 to 1/4 . Even if NCMA does allow for use of concrete sand, I don't like it because its round and tends to move more and wash faster than trap rock.

I have being using 1/4" inch for quite sometime now and it works really good I use it for patios and walkways as well.
Before we use to use sand or stone dust mixed with portland to avoid any sand migration but now it's only 1/4" or even 3/8"

As far as keeping walls straight just use a string and the next rows have to be somewhat straight.
If you try to use the string on every course then you end up not aligning the blocks with the pins lock up 100% and even you have a straight wall overtime the force coming from behind will push that wall out, in the best case scenario it will align the block to the ping worse it will force the block out and failure will start at that point.
from time time to time some rows will vary they will not stay as the base row but unless the difference is a lot we fix misalignment once we install the coping.

PS by he record I don't care what anyone will say about using it for patios and walkways this topic has being discussed several times so let's not start another bedding material tread.

zedosix
01-08-2009, 03:22 PM
PS by he record I don't care what anyone will say about using it for patios and walkways this topic has being discussed several times so let's not start another bedding material tread.

Its ok, not everyone is doing it the right way:)

kootoomootoo
01-08-2009, 10:28 PM
Stone Dust Here Also.
I always have a few bags of mortar on hand and use it.

loupiscopolandscaping
01-09-2009, 08:35 AM
string line and 6ft level for the back of the blocks

cards1
01-09-2009, 05:50 PM
Thanks for all the input guys!!
Sounds like we're all on the same page as far as stringline and 4' level i was just curious to hear some of the different responses.


Have you guys ever heard of running rebar through your base rows for extra support? We had to redo a collapsed wall(done by another company) and they used it going around tight corners. Needless to say the corners were the only sections that didn't blow out. The wall had no drainage or rock backfill and only 2-4 inches of base rock. So we ended up redoing the whole wall.

Bru75
01-09-2009, 08:03 PM
Sounds like they needed the rebar because the rest of the wall was built wrong. I wouldn't use it unless told to by an engineer.

btammo
01-10-2009, 03:40 PM
Corner was stronger probably where a blow out is easier to happen on a straight run.

The problem I run into is that we take our time (Probably more time than most) on the base course. We get it dead nuts level side to side, front to back and all dead on line with string. Put the next course on and it says low in the back or something other than level which it should be. Drives me nuts.

The other thing with the split faced blocks is that if you string the back of the blocks, the fronts will wave a little due to the imperfection of a split face cut in the manufacturing process......We use Anchor

Bru75
01-10-2009, 03:47 PM
I know exactly what you mean. I've found that some brands are worse than others for that.
I get the blocks as straight as possible, then make sure the caps are perfectly straight. This seems to make it all look right, even if there are slight differences in the blocks.