Why Use Open Graded Base for Pavers and Retaining Walls

[@Ashipan99]

Hi thank you for a great informative video. I have a tree right next to the area where I would like to build a patio. I want to maintain water drainage for the tree so open graded base sounds like the way to go. What do you think about using geo grid to hold the base material and the paver stones on top. Can I skip screeding assuming the geo grid is flat?

[@iamahardscaper]

Are you talking about having your 3/4" clear, then geogrid, then pavers? No, you always need a bedding layer to level the stones. 3/4" clear is not fine enough.

[@Ashipan99]

@@iamahardscaper thank you for the reply. sounds good I'll add a bedding layer on top. Is it correct to assume that if I use a geo grid and retaining wall around I don't need to dig and that pavers will stay in place because of the geo grid?

[@iamahardscaper]

You always need to get the organics out and to have sufficient base underneath. For us in Toronto, that means a minimum 6” base

[@javierechaniz5713]

Planning to install pavers around a shell pool. The area is a clay/sand mix. Plan to install drainage channels on two sides of the pool that are closest to the home. The pavers have minimal joint space. What type of base and joint would you recommend in my case?!

[@iamahardscaper]

for a pool patio you could go either route. it would not matter especially when you plan to install drainage channels. I still prefer open graded base, but whatever you think is easiest and that you have easy access to materials (it is difficult in some regions to get 1/4" open chip)

[@javierechaniz5713]

@@iamahardscaper other than concrete sand they have 78 pea gravel, would that also work for bedding… and if so how much compaction should I account for?!

[@MrVenezuelamagic]

Can I use #57 rock in place of 3/4 clear

[@iamahardscaper]

Yup #57 is what you need

[@Fraishe]

Top level production video in the hardscaping niche on youtube, truly amazing

[@iamahardscaper]

Oh wow I appreciate that

[@samtau1310]

That is not a retaining wall lol. Thats basically freestanding. Otherwise good video with helpful tips.

[@iamahardscaper]

haha thank you! I don't know which one you are referring to, but there should be a retaining wall in there just not shown backfilled.

[@LandscapeMaster33]

*Use concrete as a base. You'll never have issues. The way it sits after you install it. Is the way it sits forever. Never moves. More expensive, yes. However up sell it as its a legitimate way for precast to never move like soooooo many projects around do.*

[@iamahardscaper]

💯💯

[@kentr.1391]

Do you screed the concrete then lay the pavers on the wet concrete or Do you just use mortar and lay it

[@LandscapeMaster33]

@@kentr.1391 you pour the concrete in the forms like as if you’re pouring concrete as a finish project. Just less the thickness of your pavers / slab. You install the pavers on the concrete once it’s cured. Just like doing an overlay over an existing porch.

[@joelklopstein5064]

Great video! I am making a patio now using this method and have a question: do you think I can use 2 inches instead of 1 inch of the 3/8 screed layer? I need a little extra height but I’m not sure if that would cause instability or not

[@iamahardscaper]

We try not to go any more than 1.5” for our screed layer. I’d say you’d likely get away with 2” for a patio application, but it is more of a judgement call for you.

[@joelklopstein5064]

@@iamahardscaper thanks!

[@tspfull]

This video has answered so many planning questions I have had about what is best for my particular DIY backyard project. Thank you for providing all the logic behind the decision making.

[@iamahardscaper]

Glad this has helped!!

[@TechGalaxyExpert]

What does the open graded mean?

[@iamahardscaper]

Open or Clear refers to there being no fines / dust / sand

[@TechGalaxyExpert]

@@iamahardscaper thanks great 👍

[@apilkey]

So if I have retaining wall 20” away from my house foundation and about 18” high that I’m using for both a sitting bench as well as Planters against the house what sort of Base Material should I use? Also for a Patio Base what’s the difference between ASTM 57 and #5 and which one would you recommend as a Base Layer prior to putting down 1” of HPB for my Bedding Material?

[@iamahardscaper]

Use the ASTM #57. I like open graded for planters. Just be careful with doing that up against the house that you aren’t work water down to the foundation. You also don’t want to put anything against masonry brick or siding.

[@apilkey]

@@iamahardscaper Thanks for the response so what material should I put up against my house foundation after I excavate down about 18”? Is there some sort of water impenetrable cloth/material I’m supposed to put by code so the foundation integrity doesn’t get compromised by water?

[@iamahardscaper]

There’s no code. But we’ve used a similar product to pond liner to shed water away from a foundation. We’ve also just made sure that there is a low spot that slopes away from the foundation so that water collects there and sheds away from the foundation rather than sitting there.

[@marcbellante7833]

Great video! Looking to redo the pavers around our pool which were layed on top of concrete. Is the open graded base recommended for my situation where we would be putting it on top of concrete?

[@iamahardscaper]

It just depends on the height that you have available. Are you tearing out the concrete or laying directly on the concrete?

[@rorycompton8138]

Do you feel polysand will hold up better over time than a permeable jointing compound? Techniseal specifically states the permeability over time will degrade as material moves into the pores.

[@iamahardscaper]

The permeable jointing compound needs to be pressure washed probably a little more often than polymeric sand. But it holds up better to pressure washing. If you have a lot of foliage around your patio, you’d likely have to pressure wash once or twice a year. If not, you could probably get away with every other year.

[@michaelboyenko6422]

I have watched a lot of your videos, they offer top notch info and are extremely valuable, so thank you! I am located in Sask an I am planning on installing 4' sidewalk next to my house foundation. Its is already excavated so synthetic base is not really an option. You recommend using dense grade next to foundations, but I would really like to use an open base for all of the reasons one would. If the sub base is sloped 2% away and woven geotextile is used and wraps up both sides of the base, could open base be used in this case? Thanks!

[@iamahardscaper]

Yes I have done this from time to time and it is fine 👍

[@marktreichler9289]

@@iamahardscaper I have a similar situation to Michael above. Installing a patio. Part of the patio runs along the foundation of my house. I plan on using open graded base and like the idea of using the woven geotextile along the foundation but have a few questions on how to properly do that...Question #1 - Should the geotextile be put in between the open graded base (3/4 crushed rock) and the foundation? Question #2 - How far out from the foundation do you recommend running the woven geotextile until I switch over to a standard landscape fabric for the rest of the patio? Let me know if that doesn't make sense. Thanks in advance for your advice.

[@Al-xk7wl]

Your videos are very well detailed and explained! I have an interlock walkway around my home that is on lime screenings and clay soil. It’s sinking and heaving. Should I dig up all the lime screenings and relay with three-quarter inch stone and HPB? Thanks!

[@iamahardscaper]

Thank you! Without seeing it in person, I cannot give advice on certain circumstances. But lime screenings is no good. I would dig it up, compact the sub soil, install a geotextile, then install your base whether it is open graded like you suggested or a dense graded or a synthetic base. I will be touching on the other two in videos this week.

[@nappyjim]

New DIYer here looking to do a retaining wall. Middle of minnesota, sandy soil. Can you explain why i would ever NOT want an open graded base? Wouldent i always to move the water away from the blocks as quick as possible?

[@iamahardscaper]

If there’s no lower area to drain to. You have to visualize that if you use an open graded base, the drainage pipe behind the wall would be placed lower in the base material. So if it is lower than the wall, you need a lower area in your yard for that water to be moved to. But if you have a dense graded base, your pipe is above the base in the backfilled area which allows you to move water through an outlet in the wall face along with anywhere at the end of your wall. Hope that helps!

[@nappyjim]

@@iamahardscaper why do you have to have the drainage pipe buried in the base material with an open graded base? Why cant you have drainage pipe above the base material in backfill area like you explained it would be for dense graded? Wouldent it still capture most of the water? And the water that made it past into the open graded base would be gravity drained away from bottom blocks and into sandy soil below.

[@iamahardscaper]

If you’re on sandy soil and know it will drain well you could. But the reason why you’d want it lower is so the base doesn’t fill with water before finally reaching the pipe and then moving out.

[@CKT808]

Landscape places around my area carry 5/8" clear crushed stone and dont seem to have 3/4" . Would that work instead of the 3/4" for an open graded base?

[@iamahardscaper]

I can’t say for certain without seeing it unfortunately. But I would ask contractors in your area if that is what they use

[@CKT808]

Thanks for your response. Out here in the Pacific Northwest (Western Washington) seems like hardscape guys are using a dense graded aggregate as the standard of practice practice. Most guys will use 1/4" minus as both the base layer and screed layer, kindve like an all in 1 product. I'll probably end up trying the 5/8 inch clean chip for the base layer and see what happens 🤞. I am mainly going to use it to compact a bit in the subsoil, then build up an area about 3-4 inches then use a synthetic base. Thanks for bringing your innovative methods and great explanations to KZbin!

[@iamahardscaper]

Glad you enjoy the videos! thank you

[@dvillanueva13]

Hello! I live in the Southwest (Albuquerque, NM) and I am having an impossible time finding "clear" stone for either a 3/4 open graded base or a 3/8 screed/bedding layer. Is there any reason that all landscape rock providers here would not offer these sort of aggregates? I thought it may be due to the desert lack of water, but am unsure. Should I continue to seek a clear base and bedding layer, or go with what is offered? The NMDOT approved base course is incredibly dusty, and the crusher fines are all colored and mostly fines.

[@dvillanueva13]

Additionally, what is the style/type of paver you are using at 6:13 in the video? It looks to have spacers built into the paver, and comes in three sizes, but I cannot find any to purchase in my searches!

[@iamahardscaper]

It’s tough to say without knowing the market. It doesn’t surprise me that clear aggregate is not available there though. I would either reach out to a few established contractors to ask what they use and if they have used open graded and see projects around your area to see how they hold up over time.

[@iamahardscaper]

That is Blu by Techo Bloc

[@adamarriaga2626]

So if i do front yard pavers for waliking area do i use dense graded base for a slope going to the street

[@iamahardscaper]

If it is going to be right next to your driveway, I would use the same base material as the driveway. My guess is that it would be a dense graded base

[@RobHTech]

great vid. I like that tool he's using to move the stones around.

[@iamahardscaper]

Thank you!

[@neverrestboxinggym]

I love using this base, but lately it’s been tough on a lot of my patios finding an area to day light the pipe

[@iamahardscaper]

Yeah that can be difficult. I know some people don’t even bother with that aspect of the install and claim they don’t have issues. But I like to personally include it on all my installs.

[@AbundantLandSolutions]

Super great video thank you!

[@iamahardscaper]

Thank you!

[@carlw]

Interesting. So you don't always have to cap off the open graded base with HPB then? Just certain applications?

[@iamahardscaper]

Only for retaining walls 👍

[@haydeneverett1990]

This video is value added and has guru level vibes.

[@iamahardscaper]

😂 Word has spread that I am a guru

[@donray2435]

Boom goes the dynamite

[@iamahardscaper]

🙌🙌