View Full Version : Base Course

10-17-2012, 08:26 PM
I'm having trouble getting a base course level on a 110ft wall. Is there any reason that I can't set the base course of versalok on a 3/4" bed of mortar? My crusher-run leveling pad has some ridges and valleys that I can't seem to eliminate. Thanks.

DVS Hardscaper
10-17-2012, 09:03 PM
A million ways to skin a cat.

We get the compacted aggregate base as level as possible using a laser lever.

And then we cheat (sometimes) - we'll use NO more than 1/4" of sand to help expidite the process of installing the base course.


10-17-2012, 10:09 PM
Thanks for the reply, DVS. Most of the walls that I've done have been much shorter than this one. I've laid the of the base course twice now and ended up pulling the block out because I keep getting about 1/2 inch out of level after 30 feet or so.

I was thinking that if I can use a mortar bed between the CR6 and base course then I may have more success by squishing the blocks down to level, rather than building one up on sand, pounding the next down, building up, pounding down, etc.

Is a thin (3/4") mortar bed something that has been used in the past, or, is it an absolute no-no?

10-17-2012, 10:14 PM
I do the RCA base, tamp the hell out of it getting it close then put a half inch of fine sand and dialing it in. pound the lips of the block in and go

10-17-2012, 10:16 PM
Sounds like a good place for flowable fill?

10-17-2012, 11:31 PM
A tightly pulled string level and a tape measure.

10-18-2012, 12:15 AM
i dont like line levels. transit the two pins, mark them, and pull the hell out of the string

10-18-2012, 10:01 AM
A few things i have found helpful.

1 use concrete spreaders "comealongs" to spread gravel, a steel rake separates the material
2. Use a high quality laser $1000.00 price range minimum, if you cant afford, rent.
3 string lines are not good for elevation control over 40 feet. Wind and gravity take over. You will never get a line tight enough for a 100 foot run.
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10-18-2012, 12:31 PM
I've used the "mortar" approach in the past, after discussing it with a Versa-Lok rep. No problem as long as it's under an inch in thickness, and it's not relatively strong. I believe I actually just used a very lean Portland cement and sand mix, as it wasn't sticky at all and had better leveling properties.........

Mr. Midwest
10-18-2012, 01:10 PM
Im not trying to be a jerk at all but are you sure that your level is working correctly? I have had guys run base and keep getting off only to find out that their torpedo level is off. There has to be a reason why your all of a sudden running unlevel base.

10-18-2012, 01:13 PM
Don't use a torpedo. I use a 10 or 16' aluminum screeder with a 4' level where i can, otherwise i have an 8' and 6'. Use the biggest level you can
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DVS Hardscaper
10-18-2012, 02:05 PM
We don't use a level other than a line level for aggregate installation.

For setting the base course we use a torpedo level.

(For those who wanna be like me)

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Mr. Midwest
10-18-2012, 05:02 PM
i was referring to the base course being set with a torpedo level. The aggregate is height is set with a transit

10-18-2012, 05:54 PM
You use mortar and you better be sure it is right the first time, no going back once that block sets. Shouldn't have any issues with smaller block, but for a 110ft wall I am guessing you are using the monsters. In that case the mortar has to be mixed right, slurry enough to spread but thick enough to hold the weight of that block without settling.

10-18-2012, 10:17 PM
Thanks a ton for all the advice and suggestions. I think the main problem with this run was that I did not pay close attention to leveling my crusher run. I went back with the laser level and noticed that I'd be 1/4" low for 8-10ft then transition to 1/2" high for the next 20ft then back to 1/2" low for 20ft and so on. Lesson learned there. :)

As for the mortar, for the blocks 1/2" or more low it was real easy just to slap down 2-3 trowels of mortar, flatten it, move the block in place, wiggle, wiggle, and boom(!) spot on with the laser. When I tried 1/2" of sand it always seemed to push out too easily, thus requiring lifting the 84lb versa-back-ache again, and again, and again. :hammerhead: