5 main causes Retaining walls fail.

ready to back fill here soon we got rain coming tonight so at that point before it was supposed to rain and then the Packer broke down back filling and stepping up and out of this hole we're in all right guys there's five common reasons why retaining walls across the United States fail it doesn't matter what part of the country you're in the five things that I'm going to list you're going to see no matter from the Midwest from the East to the north to the South to every part of the United States these are the five most common things you need to keep your eyes open for when you hire a contractor to come out and build your retaining wall or if you are a contractor to watch to make sure that your subcontractors and your employees are doing properly cuz this is why they're falling down guys let's hit [Music] it all right show this job side a little bit making a little progress pretty steep ready to back fill here soon we got rain coming tonight so trying to get this built up go one more course and then uh start back filling prepping for rain cheap block that's the number five reason this is where a lot of contractors like to cut corners and buy the cheapest thing they possibly can now if you are a customer couple of the things you want to keep your your eyes and ears open for are block that are not Hollow and a lot of times a block will look solid but will actually be Hollow from the bottom side and this is where you go to those big box doors you'll see the blocks are Hollow you actually have to take the block flip it upside down and what you'll find a lot of times is there's a core underneath there that Hollow core is put there specifically to make the blocks lighter so they're easier to handle less material so they cost less but what happens with those hollow blocks from the bottom under is especially if you're in Minnesota you get a freeze thaw cycle and your water will actually sit under here and as the water freezes it expands when it thaws it contracts freeze Tha freeze Tha so you're you're retting almost constantly in a state of doing this and and in the beginning it should look just fine but after years of doing that your blocks will start to shift they'll start to get kitty wed Compass they'll start to get crooked and your wall will fail because the bottom block and the top block above it are not properly seated and properly connected so they're basically just slapped on top of each other and laying there a good block is a solid block this is where we use these versalock standard units it's solid and it's pinned so it has holes in it specifically lined up to allow you to drive a pin from one to the other my daddy always taught me that if you want to build something and you want it to last you're going to put a leg bolt in it you're going to put a screw in it or you're going to put a nail in it if you just slap two things together lick them and stick them and say that ain't going nowhere well it's probably going somewhere so make sure that you got a good block that has a good pinning system and that is the number one thing now it's not number one it's the number five thing to look for when you're getting your retaining walls built make sure you know what block you're getting and you choose that block and if you're a contractor your reputation rides on you getting a good block for me it's cheap insurance it does cost more but you can charge more for a Better Block if it's if you're if you're pinching pennies because of the block you use you're basically on a race to the bottom because you're going to be cutting Corners everywhere to get that job and it's not going to be good for you but let's move on to number four all right finally to the point where we're backfill now yesterday we at that point before it was supposed to rain and then the Packer broke down got ourselves a nice little replacement Packer here the bow mag looks pretty good coming along couple more courses to go I've seen some of the best contractors well in theory they were the best contractors in reputation best contractors building some of the biggest retaining walls use this do this mistake and it's right here using the wrong drainage and the wrong base material this is freaking huge and where a lot of retaining walls fail if you have a contractor show up at your site using p Rock and that's what they're going to base your wall on or they're going to use it for your drainage Zone Fire them right there it's the worst possible thing you can do because perck as water flows through it pck rolls and moves it doesn't have enough weight to it and it has the wrong shape to lock together what we always use is 3/4 clear so no matter what happens when we use a 3/4 inch Stone and it's angular in nature no matter which way you put it you put it down these rocks lock together just by their very nature no matter what you do they lock together where with pcks when you try to put them together they roll they move and they they go all over that's what happens is you when you get a lot of water running through a retaining wall behind that retaining wall those rocks are rolling they're actually loosening up the soil behind the retaining wall and that's allowing the fines in the soil to then migrate it's actually loosening up the soil behind it so as this the rocks are rolling the silt is then coming out of it because of the the movement of the Rocks you need a 3/4 in or larger stone for both your base and for your drainage zone now some people will say that you can use a concrete base I would not I would not use a concrete base for underneath the retaining wall some people will also say that you can use um class 5 and you can use class 5 the reason I like 3/4 clear for my base is it does allow the water to flow through it and not stay underneath your retaining wall uh one of those miss that I want to dispel I said I was going to dispel some Miss there's contractors that are going out and doing commercial work that don't even get this next point when you butt up to a building building like this with your retaining wall you do not and I repeat this do not physically connect the retaining wall to the structure you're buding up to so if I'm building a wall up to this structure I don't pin that into the structure I don't physically connect the wall the wall has to be its own separate entity because in different parts of the country if I physically connect to this structure I then have to go to the depth of the frost footings of the structure I'm connecting to so if I'm going to put a retaining wall up to a structure and it has a 4ft frost footing I have to bury that structure 4 feet down and pin it the entire way retaining walls are designed to float separately from any structures now we've still got three more points to go so let's go let's move on to those next [Music] now when you get over 4T tall with your retaining wall or there's going to be a search charge on that wall you need to engineer that wall no matter what height it is now let's be very descriptive about what we're talking about in this video you see us putting geogrid behind this retaining wall the reason you see us putting grid into this retaining wall is because our retaining wall is going to be over 4T tall it's been designed by a licensed and certified engineer and then ran through the city for permits and then we we get all the appropriate inspections done when you need to take these extra steps is when we're talking about that search charge and a surcharge can be any kind of additional weight behind the retaining wall above and beyond a flat level surface so when you get a retaining wall that's over 4T tall you're going to engineer it but if the retaining wall isall isn't even 4T tall but it's going to have a slope on the top of it you may need to look at getting that engineered and have geogrid in it or if you have a structure like a house or a parking lot or any kind a a shed any kind of a structure that's going to put additional weight onto the soil that that retaining wall holds up get it engineered and then get your geog grid put in place this is where a lot of guys fail because they avoid this step they're afraid of it and if they're afraid of it it's because they're not experienced with it but now I'm getting a little bit ahead of the game because we're going to talk about the number one reason why retaining walls fail in just a few moments we're still on number three but I've already alluded to the number one reason all right little more progress on the wall height it's back filling and stepping up and out of this hole we're in number two compaction is King compaction makes all the difference in the world when you build something I don't care how tall it is I don't care what you're building but if your soil is going to move whatever you're placing on top of that soil is going to fail and understanding compaction is a critical element to the overall long-term success of your retaining well if you've ever driven around the country and you've noticed retaining Wells that are double Terrace where there's one Terrace on top of another Terrace and especially where those Terraces divide you're going to see sometimes you may have seen that wall take a dip or anytime that you've seen the wall take a dip it means that it's not been compacted properly here's a little known fact about retaining walls our retaining wall when it's built properly you can take the face of the retaining wall off from it and that soil should remain in place let me talk let me give you a little bit more description about it so in this case on this retaining wall over here I could remove all of these blocks now this wall is like a decade old or 15 years old I don't even know how old it is I could remove all of these blocks and the soil behind this retaining wall should not move because I've properly compacted it I've put in the right amount of engineering the geog grid I've got the drainage aggregate the only thing that this block is actually holding back is erosion at this point it's almost like the face of this block is lipstick I'm slapping on a pig I'm just putting this in front of all of the dice the the engineering and work that I've done on the soil behind the retaining wall that allows me to hold up a structure now this is an example of a surcharge we talked about a lat it's ear it's just a deck but it's still putting additional load onto my retaining wall so this retaining wall was engineered to handle that weight and if I remove the block from this the soil is still engineered to handle that weight so a good retaining wall uses not just good uh building practices with your retaining wall block but a good retaining wall the right retaining wall or the way a retaining wall should be done also works on the soil behind it so as you watch this video you notice Tim spending a lot of time making sure that the soil behind it is is compacted right is set in place right and there's certain tricks that we are doing in this retaining wall that I don't recommend for you guys to do and what you see us doing when I say I don't recommend you guys doing it because this is kind of some Advanced Techniques we know what we're doing we've been building walls for 25 plus years big walls massive retaining walls we'll go multiple tiers up we'll flip that grid over the face then we'll back fill and when we get to the level where the grid is we'll roll that grid back down then we'll continue up putting our gr our drainage aggregate in and our back fing material but this allows us to not switch gears so often not to put one or two courses in then put dirt in one or two courses then dirt we actually have it design down to the point where we can put multiple courses in and then back fill but we also know what we're doing so just be cautious if you're going to attempt to do what you see us doing in this video it's not principles it's not things that I would recommend if you're new to retaining walls but if you're an old dog and been around that block a few times you're probably looking at what we're doing going yeah that's right and the number one reason why retaining walls fail is contractors don't care enough about their end product and they care more about their profits and what that leads to is cutting Corners across all of the points that I've just mentioned using cheaper block not using the proper engineering or geog grid using pck instead of the standard kind of rock because pck costs a little bit less I lost a bid on a job and I happened to stop out to the job while the other company was building the retaining wall what I found they were using was CMU units concrete masonry units these were hollow blocks that were designed for foundation walls they had no base material at all they were just raw raw dogging it putting it right on the dirt they had zero drainage a grip behind it and there was no connection method from one block to the other block this is what the difference is is a contractor that cares is going to take all the proper steps and here's why you contractors should care you are responsible for anything you build it has to be built right for up to 10 years you don't have to give a warranty if you build a retaining wall and that wall fails and they have a licensed engineer come out and certify that you did not Build That Wall correctly you are still responsible for that retaining wall up to 10 years later you have to build it right right out of the gate it's cheaper to do it right in the beginning than to try to scramble and fix something later on don't do that but those are the five reasons why retaining walls fail let's go back over them from one to five one more time number five using cheap blocks Hollow from the bottom or any other kind of a cheat block that has an inferior connection method number four using the wrong wrong drainage and wrong base material using pck versus a 3/4 clear angular stone pck is usually cheaper it's usually easier to get it's easier to handle it's easier to shovel and a lot of times it's what contractors migrate towards because it's just plain easier building retaining walls is not easy stuff number three geogrid not using geogrid when you need geogrid not compensating for the fact that you have have a search charge on your wall if it's over 4 foot tall you're going to have to uh go toward geog Grid or at least look at do you need it or if it has a sear charge you will need Ria a geog grid this is sarch charge can be a slope onto a retaining wall or a search charge can be a building or a structure like you see or a parking lot on a retaining wall all those add additional weight to the retaining wall so i' compensating for that search charge number two compaction not understanding compaction having inferior compaction not using enough compaction it's all about compaction when you're building larger retaining walls make sure you're compacting the heck out of it compaction is cheap cheap cheap insurance so use use use it and number one caring cutting corners and versus instead of doing things right you cut Corners this is the worst possible thing because you are as a contractor on the hook for up to 10 years if one of your walls fails and a licensed engineer comes out and looks at it and says yeah this wall was never built right in the first place it doesn't matter if you gave a warranty or not because you as a contractor responsible for making sure that you build things the right way on day one that's it for this video hope you guys enjoyed it God bless go get them hope you guys build some good retaining walls for your customers and if you're a customer I hope you get a good contractor that builds you something the right way way