bdonkersgoed

Techo-Bloc Wall Stones -- Embedment Depth?

Bryan
21 days ago

Hi everyone!


I'm looking to build a wall and seating to surround a firepit using Techo-Bloc Brandon Wall Stones and Techo-Block Borealis Wall Stones for the seating. For a "Freestanding Wall", the Techo-Bloc Instructions (pg 127) says that the wall should be embedded by 6", but I'm not sure if the wall is considered "freestanding" in my configuration with the corners? My original plan was to simply lay the stones on the same HPB bed as the surrounding paver patio (such that the wall stone would be embedded by the thickness of the pavers, 60MM or 2.40"). Is this sufficient, or do I need to somehow trench the area for the wall/bench stones so that their HPB surface is about 4" lower than the HPB surface for the surrounding pavers? I believe that the Brandon Wall and the Borealis Seating would be considered separate structures since they aren't connected in any way.




Thanks!

Comments (26)

  • PRO
    Yardvaark
    21 days ago

    The wall would be considered freestanding and you need to sink the blocks 6", not just 2+.

    Bryan thanked Yardvaark
    Best Answer
  • Bryan
    Original Author
    21 days ago

    Thanks Yardvark -- you're helpful as always!


    My original plan was to use Brandon wall stones as the seating (i.e. creating a "box" that would be covered in coping). That plan would have connected the wall and the seating such that the embedment wasn't required. Now that I'm using separate Brandon and Borealis wall stones (not connected to eachother), it looks like I'll have a more complicated base preparation, but that's OK! :-)


    Here's my plan for the excavation that considers the embedment (in imperial and metric):




    A few questions:


    1.) Does my excavation/embedment plan see to make sense? Am I overlooking anything?


    2.) The Techo-Bloc instructions aren't clear about how to level the wall stones -- they simply say that you need a "pad composed of 0-3/4" crushed stone with a minimum thickness of 6 inches".
    I believe it would be difficult to level the wall stones direclty on the gravel base, so I assume that I need a 1" layer of HPB (or some other kind of leveling layer) on top of the compacted gravel?


    3.) Should the Borealis be embedded the same as the Brandon (as I've shown in the drawing)?


    Thanks!!

  • Bryan
    Original Author
    21 days ago

    House seems to reduce the resolution which makes it difficult to see -- here are links to higher-resolution images:


    Embedment (Imperial)


    Embedment (Metric)

  • Bryan
    Original Author
    21 days ago

    In terms of my plan, is this how I should tackle it?


    1.) Excavate the entire area (both the patio and the wall/seating area) down to 10"


    2.) Trench the wall area down to 16"


    3.) Compact the native soil


    4.) Lay ladscaper's fabric (geotextile) in the trench and patio area


    5.) Fill the entire excavated area with 3/4" gravel (compacted in 2" increments) until the trench compacted pad is 9" deep (and the surrounding patio compacted pad is ~3" deep)


    6.) Create a 1" HPB layer for the walls/seating


    7.) Build the walls/seating


    8.) Fill the remained excavated patio area with 3/4" gravel (compacted in 2" increments) until the patio compacted pad is 6.5" deep


    9.) Create a 1" HPB layer for the pavers


    10.) Lay the pavers

  • PRO
    Yardvaark
    20 days ago

    In general, this looks good to me, but you're building in a frigid climate foreign to me and asking brand specific questions. Maybe one of the other pros who's familiar with cold climate construction will jump in and offer some advice. (For Florida, what you're doing would be substantial overkill except for commercial work.)

    Bryan thanked Yardvaark
  • Bryan
    Original Author
    19 days ago

    Thanks @Yardvaark!


    I had a chat with an engineer at Techo-Bloc today and he suggested an embedment and excavation plan that was much more simple than what I had previously drawn. Here's my revised plan based on his description (and he said that the implied ~4.3" embedment should be fine):






    Embedment Plan v2 (Imperial) -- Higher-Resolution


    Embedment Plan v2 (Metric) -- Higher-Resolution


    He said that the wall stones are installed directly on the compacted gravel base, and I suppose this aligns with their online instructions -- but doesn't this mean that it would be really difficult to level the wall stones?


    Thanks!

  • PRO
    Yardvaark
    19 days ago

    An engineer at Tech-Bloc trumps me. You would be able to get gravel fairly well/tight in plane. The blocks are not going to be tamped down into a setting bed as one would do for pavers. They'll be set on an already tamped bed. A sparse smount of fine material to accommodate very minor discrepencies of surface would be OK as long as it is not thick and is tamped hard.

    Bryan thanked Yardvaark
  • Bryan
    Original Author
    19 days ago

    Thanks for the clarification! I guess the plan is much simpler and should be sufficient (especially since the Techo-Bloc engineer is from Montréal which gets even worse weather than Ontario!). I'll start staking out my perimeter in preparation for the excavation :-)


    In the documentation I read online, it says that the excavation slope should mirror the slope of the finished pavers (e.g. 1/4" per foot), but I'm not sure why that would be critical? I thought the slope would only be critical in the compacted gravel and leveling bed surface?

  • PRO
    Yardvaark
    19 days ago

    If the excavation slope and slope of finished pavers are in sync/matching, then the layers between these parallel planes are uniform in thickness. At least, I think that is the point being made.

    I'm sure this project would end up looking very nice; its modern design looks smart, and I can tell by the precision of your excellent drawings and careful use of terminology that that every bit of attention possible will be paid to the smallest detail. So I bring this up not to say there is something wrong with this direction, but merely to ask if you have pondered how using it will be. Will there be cushions? And storage for them? Sitting on hard masonry in a cold climate could have its issues if they are not considered ahead of time. Your thinking is probably way ahead of my question, but just checking.

  • Bryan
    Original Author
    14 days ago

    Been working 16-hr days and haven’t had a chance to make progress this week 🙁

    Thanks for the clarification — that’s what I thought about the slope!

    Thanks for bringing up the question of cushions! It’s something I’ve thought about before and I have someone who can make custom cushions to fit the final dimensions if needed. I’ll probably try it without cushions for a bit first — my sister has a stone seating Fire pit setup and it’s never been a problem (although it would admittedly be more comfortable with cushions). Although Canada is a cold climate, it gets pretty hot in the seasons when you’d actually want to sit outside 🙂 But definitely not as nice as Florida haha!

  • Bryan
    Original Author
    6 days ago

    This weekend I finally had time to mark out my perimeter and skim off some of the top surface. It's nice to see some pregress, but it was so hot here -- not a good weekend for digging my super rocky soil! After I skim off the top I'll properly mark out my elevations to get the depth/slope required in each location.



    My temporary soil box seems to be holding up well. I'm going to have a lot of dirt by the time I'm done!



    One question -- the builder seems to have built up the to concrete patio that was under my deck (see the pictures below). Do I need to remove all of the extra dirt ramping up to the patio (so that it doesn't erode onto my new paver patio)? I started with this:



    But I've already removed a bit of the ramp-up on one side:



    It would definitely add to the quanty of dirt I need to remove, but if it's necessary then I'll just have to do it!


    Thanks!

  • PRO
    Yardvaark
    5 days ago

    I don't understand the question. You might need to reference it in relationship to the plan, and the plan to the concrete. By just looking at pictures, I wouldn't know what is supposed to go where.

    Bryan thanked Yardvaark
  • Bryan
    Original Author
    5 days ago

    Sorry about that! I didn't realize that my plan wasn't in this thread! Here's a copy of my plan that I marked up that hopefully explain it better:




    The blue square shows where the old concrete slab was under my deck. The slab is about 1ft thick above grade. In the red, it shows how the builder used earth to build a pretty aggressive slope up to the slab (so that there isn't a step). I'm excavating the area in purple for the new patio, which means that I'm excavating a portion of the buildup/ramp to the slab (i.e. where the purple intersects the red); however, I'm not really sure what to do with the the remaining unexcavated portion in the red square. I'm guessing that I need to excavate back down to grade level to prevent problems with erosion/runoff? Thanks!

  • PRO
    Yardvaark
    5 days ago

    What I'm unsure about is the finish elevations of the various components. I take it that there is a gap between the existing concrete slab and the paver field that you are building now ...? When finished, what fills this gap? What is the elevation difference between the slab and the paver field? Will the slab remain as is in the finished product, or does it get covered? A cross-section sketch of the finished product, through pavers and concrete, may help explain. Call me if you need a quick answer as I will be gone most of day.


    John


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  • Bryan
    Original Author
    5 days ago

    Thanks @Yardvaark -- I guess this is tricky to describe :P


    What I'm unsure about is the finish elevations of the various components. I take it that there is a gap between the existing concrete slab and the paver field that you are building now ...?
    When finished, what fills this gap?


    The brown-orange-yellow surfaces in my plan represent the deck (to be built) and stairs. The gap between the existing concrete slab and the paver patio will be covered with my deck and stairs.


    What is the elevation difference between the slab and the paver field?


    It's too bright outside for my laser level to work, but I can check when it gets dark. By eye, I think the surface of the concrete slab is about 12" higher than the surface of the paver patio to be built.


    Will the slab remain as is in the finished product, or does it get covered?


    I'm just going to build my raised cedar deck over the concrete slab (and leave the concrete slab hidden below).


    A cross-section sketch of the finished product, through pavers and concrete, may help explain.


    I've tried my best with MS paint below -- hopefully the picture is worth a thousand words :) I'm trying to determine if I need to level off the portion in red text.




    Thanks!!

  • PRO
    Yardvaark
    4 days ago
    last modified: 4 days ago

    The answer: YES!!! Does not need to be perfect, though. (Picture totally worth a thousand words. Scratched on a napkin would have been fine, too.)

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  • PRO
    Yardvaark
    4 days ago

    BTW, have you tried sprinkling good the area to be dug the day before? If the soil is very dry it may help. Won't do much to help with rocks though. :-(

    Bryan thanked Yardvaark
  • Bryan
    Original Author
    4 days ago

    Ok, thanks! I guess I have some more dirt to move 😂 I think I’m going to fill my temporary bin, as well as the driveway in front and beside by the time I’m done! The bin holds about 13 yards and I’m close to filling it already!

    Another question — I’m thinking about doing artificial turf in the green space that’s left of my back yard. Is there a reason why I couldn’t build the base for the artificial turf on top of my grass (without really digging except to remove the grass)? This would then gain me some relative depth to my patio (such that I can save a few inches of digging to for the 10in depth required for the patio)?

    Thanks!

  • Bryan
    Original Author
    4 days ago

    My yard is more “mining” than “digging” haha! But it’s happened to rain a bit the day before I’ve been shoveling 👍

  • PRO
    Yardvaark
    3 days ago
    last modified: 3 days ago

    You would need to remove organic matter for the base for the artificial turf. It is basically like installing a paver patio. I'm not sure to what depth though for your area. You'd need to rely on mfg. specs. for that.

    I feel for you on the "mining"! Wouldn't it be nice to come across a gold nugget or two for your troubles! :-)

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  • Bryan
    Original Author
    3 days ago

    Thanks! I've emailed the artificial turf manufacturer to see what's required, but from their general online guidelines it sounds like a 3" compacted gravel base is required. If I skim off the dead organic surface of my lawn and then add a 3" compacted gravel layer, then I think this would gain me ~2" relative to my patio (such that I'd have 2" less digging required for the patio). It seems like it would be efficient to tackle the artificial turf project now while I'm already hauling away dirt, hauling in 3/4" stone, renting a compactor for my patio, and just making a mess in general :-)


    I wish I found some gold back there -- it's hard digging in my yard! My hand is so sore that it's hard to clench my fist :P

  • PRO
    Yardvaark
    3 days ago

    You're illustrating why having a plan is helpful ... that the next job might just as well be incorporated as part of this one in order to make the process more efficient.

    When I lived in the Atlanta, Ga. area (near Stone Mountain) it was IMPOSSIBLE to dig any hole without hit some, or many rocks. So frustrating!!! In Florida, the yard is pretty much just dirty sand, so it is like digging in soft butter. You can stick the spade a good way into the ground without even pushing on it with your foot! I love it! Hopefully, you will recover completely from your landscape project once it's over and you are sipping wine in front of the fire :-)

  • emmarene9
    yesterday

    Bryan, we like to see photos of completed projects.

  • Bryan
    Original Author
    yesterday

    Thanks Yardvaark!

    I spent some more time calling the turf manufacturer and then at the landscaping supplier yesterday to ask lots of questions (it was too hot to work anyways!), and it seems like my plan with the artificial turf (raising the rest of the yard) should work 👍 There are a few challenges that I’ll need to figure out with slopes but it should be manageable. I thought I had a solid plan going in, but it seems like my plan is changing a bit haha!

    The biggest challenge I have is the slope to remove water from my Firepit area (to prevent it from getting trapped by the wall. It sounds like after the wall is installed, I’ll have to do some creative sloping within the seating area to shed water in the opposite direction towards the concrete patio (and this might be difficult with the 48” plank pavers I intended on using, so I might have to switch that to something else).

    I’m really jealous of your FL butter soil! But I think I’m through the worst of it now. I’ve already hauled out 12 yards of dirt/rock. I’ll take elevation measurements after skimming off my grass to see how much more excavating I need to do in the patio area to get to 10” depth.

    Thanks!

  • PRO
    Yardvaark
    yesterday

    Seems like you will have to drain firepit area something like this ...


    Bryan thanked Yardvaark
  • Bryan
    Original Author
    4 hours ago

    Thanks Yardvaark! From what the landscaping supply person described, the sloping within the firepit could be done by some "fine tuning" with some extra gravel once the walls are set. I would just need to add and hand tamp a bit of gravel to get the new slope. The way that you've drawn it matches what the landscape supply drew for me :) Based on this drawing, I don't think I should have a problem laying 30"x5" slab pavers in the firepit area with that slope.


    Yesterday I pulled out all of my weeds by skimming off the organic layer -- it actually looks better as dirt than weeds :P And this way I can more properly measure my elevations.



    Before digging out the weeds, I had roughly determined my elevations (where 0" is my highest point). I'll get more precise measurements tonight or tomorrow night when my laser is visible.




    When I install the artificial grass, it will have a 3" to 4" Compacted Gravel base according to their specs. What's odd is that the colour brochure shows a 1.5" to 2.0" of chips/dust, but then the instructions say that you should avoid using it:




    I was hoping to put the gravel base for the turf directly on the dirt, which gains me 3" to 4" of elevation relative to the patio area. To keep it simple, I was only going to install turf in the large open area, and then do rocks between the patio & fence and between the patio & house (marked in the drawing).


    A few questions:


    1.) In order to maintain the additional 3" to 4" elevation throughout my yard relative to the patio, I guess I'd need to install the 3" to 4" compacted gravel even in the areas where I'm just doing rocks?


    2.) If I add compacted gravel between the patio and the fence, should I slope it down fairly aggressively to the fence (so that I don't have the fence boards buried in 3" to 4" of compacted gravel)?


    3.) Do you have any tips on how I should measure the elevations? Should I just measure the elevation at a number of random positions throughout my yard?


    Thanks!