HPB vs Concrete Sand for Pavers | Bedding Layer Comparison

On today's video, we talk about Concrete Sand as a bedding layer for pavers and compare it to using High Performance Bedding or HPB. This discussion was prompted by a driveway project with tight joints and why we considered using Concrete Sand for the bedding layer rather than our usual HPB.
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[@aulivn4jc]

Hey there. I work for Landscape Effects here in Windsor Ontario. Maybe you have heard of us. Anyway. I have been enjoying your content. Keep up the good work.

[@iamahardscaper]

Hey thank you for watching and commenting!

[@MyDogmatix]

Thanks! I’m a carpenter, bending to the will of a client who wants me to instal 320 square feet of pavers. Never done this much. Your terminology and description and method are great and answers my questions. Thank you sir. I had to watch 3 other videos before having someone like you get to the point.

[@iamahardscaper]

Thank you, glad it helped! Let me know if you have any questions

[@mutatioveritas4559]

Thank again for this video and all your other content! I used 1/4" chipped granite on our paver walkway and patio last year. It certainly did the job, though I would definitely argue for the 3/8" clean chipped rock as the way to go. I had an extra sidewalk to do from the main body of the project this spring/summer and opted to try 3/8" clean Grey Trap. The place I got it from also had 3/8" chipped granite, though those pieces seemed to be more consistent in shape than the grey trap and I figured more irregular shapes might be better for locking in when tamping. In short, having worked with the two, I do think that the 3/8" clean angular rock is probably the best way to go for a bedding layer. It's a nice middle ground. You get screedability with a larger, coarser size, that will likely provide a better lockup over time (less shifting and/or compression). I would suggest, if you find it works with your videos and jives with your experience, to perhaps talk about height differentials with the differing sizes of bedding aggregates and how to account for those differences in meeting a given height to aim for. For example, sand is basically completely level with the screed bars given how small it is, and while 1/4" and 3/8" clean angular rocks are screedable, you will see a lowering of the level surface as the larger aggregates will pull some of the material beneath it. You'll see a lower level surface (between the screed bars) with 1/4" rock vs sand, and a subtle difference in height between the screeded surface of 3/8" and 1/4" rock (and even more so between sand and 3/8" rock) as it relates to the top of the screed bars. That, combined with how much height will be lost due to compaction seem like interesting pieces to consider when determining a given height/metric to be aiming for when building a project. Thoughts? 🧐🤓

[@iamahardscaper]

Definitely a good topic to cover! Something I’ll consider in the future. By industry standards I believe it is +/-1/16” for height differences between pavers. Something that i should incorporate somewhere in a video 👍

[@timothypazaras4773]

Thanks for video. DIY and preparing to do a large porch patio enclosure 16'x36' with pavers instead of concrete pad. The pavers will be supporting a swim span / hot tub that will be 8' x 22' and when filled will weight approximately 34000lbs. Any suggestions on the process and what products would be best to use. Regular pavers or Driveway pavers 3 1/4" - concrete sand or 1/4"? Any suggestions would be appreciated. Thank you Tim!

[@iamahardscaper]

on our last project from last year what we did was pour a concrete pad for the hot tub and then overlay that area with pavers. Everything else around that was on a synthetic base. But with the pad being level and the pavers around the pad being sloped you have to blend the two areas as best you can.

[@Holocher]

Very informative video! I had a new 20x20 natural stone patio installed summer 2020. Tight joints (1/8 or less), 4 different stone dimensions and thickness is not uniform. The patio has a steep slope (when it rains the water flows to a catch basin). The contractor used 10 inch crushed gravel and topped it with 2 inch compacted limestone screening. The first 3 summers the system performed well (we had moderate to low rain) but the fourth summer/year the system failed due to heavy rain (washed out the polymeric sand) so I had to reinstall the polymeric sand. This summer we are getting a lot of rain, the stone is turning green and I see moss in the joints. I lifted up a stone or two and see that the limestone screening remains humid(not water wet) a while after the rain (it dried quickly after lifting the stones). I am considering getting the job redone by removing the limestone screening, keeping the 10 inch gravel (under the gravel the base is sand) and use concrete sand as replacement for the limestone screening. Ideally I would use HPB but it does not seem to be the correct solution because of the tight joints, any suggestions?

[@iamahardscaper]

Are there trees overhead? Is there a lot of shade on the patio (minimal direct sunlight)? I personally do not like using HPB for natural stone square cut because of the tight joints as you mentioned and because when you lay 1" material with a large surface area on HPB you get a hollow sound walking on them. An alternative to this where you can have a permeable base would be to widen the joints slightly to install this system: kzbin.info/www/bejne/lWLdhI2hp6edsJo Expensive, but it would be a patio for life.

[@psykox]

Hi, this video has really got me thinking. Was wondering. Do people ever use 3/4" clear and hpb for bedding when doing stairs/steps? What is your preference?

[@iamahardscaper]

Yes, my preference depends on the application. If the surrounding area has a place to drain, then I have no problem going that route

[@squests3139]

@@iamahardscaperhmm, the hole purpose for 3/4 clean, HPB is to max drainage right? Sand may compact with 3/4 clean stopping draining that is why you use geotech between sand and 3/4 clean. Do you agree? And is home depot sakrete leveling sand the Samething as concrete sand? Thanks

[@kevinkapalka4509]

Watched many of your videos and found them very helpful! I'm doing a patio in my backyard with pavers and I'm using HPB w/ gator base. I unfortunately excavated more than I suspected and have close to a 3" - 3.5" layer of HPB. I think I saw a comment from you on another video to not go more than 1.5" - how could I still make this work with 3" in some areas? I plan to backfill the edges with soil to hopefully prevent washout and have a non woven geotextile separating my subsoil from HPB

[@iamahardscaper]

I would use a dense graded base and compact that into your subsoil. Then use non woven to separate and then your HPB.

[@mutatioveritas4559]

Thanks for the great video! I ended up doing a 1/4" chipped granite bedding (thanks to these videos) over class 5 (which was already on my driveway before I learned about the open aggregate option). If I recall, you're in Canada? I'm in Minnesota and I have to say, I've been pleasantly surprised at how easy the pavers are to maintain in the winter. With concerns over chemical de-icers and their effects on pavers and joint compounds, I was worried I would have icy pavers without much to do about it. I don't know if it's drainage or that the rock bedding affords some degree of an air gap with the class 5 underneath, but when we've gotten snow, I simply shovel it off and the pavers during the day basically defrost from the remaining thin layer of snow left after shoveling. The pavers just warm up significantly more than does our blacktop driveway. My best guess is that the class 5 underneath the blacktop is frozen, so the sun has less of an effect on it, while the rock bedding under the pavers allows the pavers to have a gap between themselves and the class 5 allowing them to warm up more effectively with the sunshine. Thoughts? I'm wondering if this is normal for pavers regardless of the bedding layer, or if this is yet another perk to using an open aggregate for the bedding layer? Or more simply, have you seen this as well in terms of how these HPB installs fare in colder climes in comparison to sand bedding installs? The product we installed is Techo-Bloc's Blu 60 Smooth in HD2 Chestnut with a chocolate brown Victorien soldier course. So it's basically a dark tan/caramel colored paver, but obviously not as dark as the blacktop driveway, which was always markedly hotter in the sun during summer than our prior grey, poured concrete walkway.

[@iamahardscaper]

Yes, I am surprised that it is having an affect with just your bedding material. But with an open graded base which would be 3/4" clear instead of your class 5 and 1/4" chip as the bedding, there is enough air flow to prevent freezing. This keeps your pavers from accumulating snow as long as the temperatures do not remain freezing for long periods of time or large amounts of snow. Glad to hear that you are seeing this with your project! Let me know if it continues.

[@mutatioveritas4559]

@@iamahardscaper Thanks for the reply! Good to know I wasn't just imagining things or thinking I was on to something that is common to all pavers regardless of install method. 😆 We had considered using one of the resin-based joint compounds, but the tight gaps on the Victorien brick pavers made it a no-go. We did the polymeric sand instead, which I understand is less permeable and is better able at allowing the water to follow the slope off of the pavers, whereas the resin stuff allows water to sink down into the bedding and base layers to run off. Perhaps that has something to do with helping the 1/4" chip rock/open aggregate bedding layer to act as an insulating layer? To be clear, one of the better examples was the day after we had gotten some snow. I had shoveled that night and we were supposed to have a sunny but frigid day the next day, so I thought, "This will be a true test!" Sure enough, we started at -3º F, got up to a whopping 17º with a fully sunny day, and the residual snow left on the pavers from shoveling progressively disappeared throughout the day. 🤩 I have no idea if it makes a difference, but I'm also wondering if it helps having the HD2 product as well. e.g., Would the extra density of the upper layer on these slabs be more responsive to warming from the sun than more porous non-HD2 slabs? 🤔

[@iamahardscaper]

Sorry, missed this comment. That is a possibility, as well as if it is a darker color as well.

[@azmtkdzv]

I can't find an answer, please help: some lay with sand (no matter the kind), and some use cement to build it I guess tougher the structure. Explain why one *need* to use cement or sand. Pros and cons. I'm an amateur as one might notice

[@iamahardscaper]

It just depends on the application and climate plays a factor as well. Here in Toronto, using a mortar to adhere is not a great solution for pavement because it traps water. Sand instead will let water through rather than trapping it so it won’t cause problems in the winter.

[@vilasn16]

My landscaper just used high strength concrete instead of poly… what might happen???

[@iamahardscaper]

polymeric sand flexes with the movement of the pavers from traffic and freeze-thaw cycles. Concrete does not flex, so it will likely crack

[@stevenforrest6843]

I am a DIY’er and doing my first patio. I am using a synthetic paver base and planned to do concrete sand, however some of your other videos I think I want to use the HPB limestone instead of the concrete sand. Since this is my first patio, I assume my gaps will be larger. Will the HPB hurt in this aspect? With HPB as my under layer, can I still use sand to fill in my joints on top of the pavers? Also, do I need to compact the HPB? So I need to compact the pavers as well?

[@iamahardscaper]

The joint widths don’t matter with paver base panels because your bedding layer are the panels so no bedding moves into your pavers from the bottom up. Also most pavers have built in bumpers on the sides that provide the joint widths. Yes you can use sand to fill the joints for paver base panels. You do not need to compact the HPB, just the final compaction of the pavers with protection while installing the jointing compound. Concrete sand as your bedding would need to be compacted before installing the panels. Hope that helps!

[@garya2223]

Can you comment on using HPB vs sand bedding for paver panels (Brock, Gator, etc), especially regarding bedding compaction. Since the panel rests in the bedding and the pavers rest on the panels, the bedding can't work it's way up between the pavers so there is no compaction happening there. Brock recommends 3/4" sand compacted down to 1/2" and they don't mention using HPB at all, so I'm confused.

[@iamahardscaper]

Yeah I don't think Brock is into the industry too much, but they license their product to other manufacturers like Gator Base (Alliance) and EZ Base (TechniSeal) and they both say either sand or HPB. Sand needs to be compacted as well for both of them, HPB does not. And yes, you do not get the interlock that you would with other base materials which is partially why it is not rated for vehicular or heavy pedestrian traffic.

[@garya2223]

@@iamahardscaper So the HPB (or #9 clean angular stone) does not need to be compacted at all, under paver panels?

[@carlw]

Excellent discussion thanks👍🏻 As you know Mike, I'm redoing my patio. 25 years ago I used a couple of inches 3/4" then 3-4" screening then screeded 1" sand. It stayed solid as a rock for all that time and didn't heave. However, when I removed my pavers I notice all the sand had infiltrated the screening. So at least I have a good strong base of screening now which is like a concrete pad and a section of clay (expanding part of the patio). So as per your videos and discussions I'm simply resloping and relevelling my screening/clay soil, compact with plate compactor, non-woven geotextile, 3/4"-1" HPB, Gator Base then 14"x28"x2" (50mm) slabs followed up with polymeric sand. Since I can't use a plate compactor to vibrate the polymeric sand into the joint and likely no one rents a roller compactor I'll just use my hand tamper with a piece of carpet duct taped to it. Yes it's a MacGyver but should work. It has to, I'm not buying a roller compactor for one use. 😃 Cheers and thanks for your videos.

[@iamahardscaper]

Thanks for commenting as always Carl! I always appreciate it. Everything you wrote checks out in terms of installation. Make sure you compact the subsoil 👍

[@carlw]

@@iamahardscaper Thanks. Yes, agreed and luckily, its mostly clay with no organics. At least the screening doesn't need compacting but since I'll be renting a compactor I might as well give it another massage.

[@carlw]

@@iamahardscaper BTW, forgot to mention, I went to pick up some 1/2" black pipe (3/4" O.D.) screed pipes at the big box store by Yorkdale. I picked up the mini skid of 5. They're ~$17 each right, but there was an issue with the computer at checkout. I ended up getting the skid of 5 for $17. 🤫🤫

[@iamahardscaper]

What a deal!

[@carlw]

@@iamahardscaper LOL

[@davycrockett4406]

Loved yer clear explanation of the different aggravates. I want to top up my driveway w/ gravel, and set in two patio stones to my front porch steps. Seems as I underestimated myself, and put down 1/2” gravel, and bought brick sand for the front porch. Now I know, at least to get concrete sand and 3/4” gravel. I’m in Toronto, ON Cda. Thx!

[@iamahardscaper]

Glad it helps! I am also in Toronto 👍

[@SUPRAP2]

What do you recommend? I have large 24 inch pavers that have a 4 inch gap. I want to put something inside that 4 inch gap that is less hard than concrete but stronger than fully cured polymeric sand (which is easily damaged and requires re-doing part of the job later on).

[@iamahardscaper]

You may be looking at a polymer modified grout. I don’t know what the base looks like though

[@joequixotic3039]

Do you have any opinions on using "mechanical concrete" (recycled tires with the sidewalls removed to create a jumbo geo-cell style reinforced road base) base under a paver driveway? I am trying to find 50 year+ longevity for everything I build on my property, including a driveway that goes over a fairly large culvert (or several smaller culverts in a row).

[@iamahardscaper]

Unfortunately not, I have not tried that

[@josemedrano3836]

I work in Northern Illinois we use sand beding we have a lot of Clay soil when you use 3/4 chips and 1/4 chips base and paver Beding dosen't water goes throu and ponds on base and if it's close to winter dosen't heabe up

[@iamahardscaper]

We have a lot of clay here as well. Sloping your subgrade away from the foundation and having an area for water to flow outside of the project area.

[@shirleyjest8838]

Hi, what is the ideal joint distance for concrete pavers? Some pavers come with raised areas to set the distance. What do you do when the pavers lack these “bumps”? Does this change if using sand or base panels?

[@iamahardscaper]

If there are no space bars on the sides of the pavers, aim for a 1/8" joint space. Though some pavers are designed with no space bars but are slightly tapered to allow sand to fit in between the joints like these shown in the video. This still allows sand to make its way down even though they do not have space bars on the sides of the pavers. This does not change.

[@LuminairPrime]

REALLY good video with LOTS of practical bits of experience developed over years of work. Keep making these videos!!!

[@iamahardscaper]

Thank you!

[@kranerwheatens]

Went to the stone yard today and not sure if they sold me the right stuff. Its a small angular down to dust. I think you said down to fine. I don't want it to hold water or settle to a lower height of the garage concrete I'm leveling to.

[@iamahardscaper]

That sounds like stone dust. Search our stone dust video on our channel to see if it is the same

[@Nightside13]

Great, that settled that! Can't find chip stone anyway in LA. Local yard never heard of it.

[@iamahardscaper]

Yeah California I heard is tough to find this

[@charliecalzadilla6028]

I used synthetic panels. The manufacturer of the pavers changed their height on the border/soldier course. Half are 2 3/8 the other are 2 1/2. The main pavers on the patio are 2 1/2. What can put on top of the synthetic panels to bring the shorter pavers up so they are flush with the rest of the pavers. Your thoughts please.

[@iamahardscaper]

Between the edge restraint and the main pavers, use concrete sand. So lay the border up against the main pavers, install the edge restraint, take out the border pavers, lay some concrete sand, and lay the pavers back.

[@charliecalzadilla6028]

Thank you kindly. Such a simple solution. That’s why your the pro.

[@daveprattdesignspaverproan265]

I disagree. Mfg joint sand and well compacted will not move

[@iamahardscaper]

👍👍

[@charliecalzadilla6028]

Hello, do you ever seal the pavers to make cleaning them easier? If so what product do you use and or recommend?

[@iamahardscaper]

I let clients know it is an option. Check out Alliance or TechniSeals products.

[@charliecalzadilla6028]

Thank you much sir. Really appreciate your advice.

[@The_real_dylan]

I can't find anyone with this stuff in SOCAL

[@iamahardscaper]

Yeah I don’t think it’s made it’s way out to you yet

[@Sasataf]

With tight joints, could you still use HPB?

[@iamahardscaper]

You could, I wouldn’t for driveways though

[@kingcaveman6811]

Can u use pee gravel for bedding

[@iamahardscaper]

No it needs to be angular crushed

[@JesusisLord78]

How thick should the sand bedding be in centimeters please

[@iamahardscaper]

2.5-3.75 cm

[@Klis1517]

​@iamahardscaper Is there a problem if my 1/4" chip is less than half an inch in depth? I have a slight high spot of dirt where I'm laying my pavers. I'm basically screeding away all the 1/4" chip away from this high spot. I'm using the foam paver base pads and they're basically sitting on the compacted dirt in that high spot section.

[@R0T0RGUST]

Why am I exhausted listening to this?

[@iamahardscaper]

😂 I’m sorry you have to listen to this voice

[@robertsavage6489]

I think it's more about the plethora of information to digest all at once. No complaints, though!

[@DaveC-sx3gl]

I'm working on a backyard patio. Originally I was going with an open grade base but my backyard slopes toward my house and found the ground to be wet. I've excavated and sloped the base away from the house. Not wanting to have water sitting against my foundation I've started to put (A-gravel) into the excavated area and I am compacting frequently. I have 1" screed/galvanized conduit rails and want to be prepared for my next step. Should I use HPB as a bedding layer or concrete sand in this scenario? I'm going with a 2" thick paver from a local company in Ontario (BSW) I think is the name.

[@iamahardscaper]

I'm in Ontario too 👍 When it comes to a patio, we always use HPB for the bedding layer

[@DaveC-sx3gl]

@@iamahardscaper Hpb on granular-A. Would you still use a concrete edge restraint or something else?

[@iamahardscaper]

Yes, I almost always prefer a concrete edge. Make sure you scrape away the HPB before you install it. It should adhere to the base and the pavers.

[@DaveC-sx3gl]

@@iamahardscaper thank you. I always look forward to your answers on rainy days. Tomorrow's forecast for the gta is no rain. Hopefully I can get my patio granular-A base in and compacted. Fingers crossed.

[@roberto.gallegos]

Can’t find it in Colorado either

[@iamahardscaper]

I know of one contractor that uses it in Colorado. Denver area

[@roberto.gallegos]

@@iamahardscaper oh man, by any chance can what’s his company info. Maybe and can reach out and see where he gets his material.

[@iamahardscaper]

Try reaching out to DTE Landscaping on instagram

[@roberto.gallegos]

@@iamahardscaper I don’t have social media but I’ll try reaching out to them a different way. I hope I just get some info and direction from somewhere in my area on where I can go.

[@parkerbirch5286]

PUKE!!!

[@iamahardscaper]

Puke?

[@chatderue]

Great !!

[@chatderue]

with concrete sand the compaction is 3/16 inch ? If you had done the whole project, whould you have used hpb instead ?

[@iamahardscaper]

I aim for around that 3/16” per 1” of screeded sand for compaction. If I was doing the whole project with this same material, probably concrete sand still because of the joint widths.

[@chatderue]

@@iamahardscaper good thank you !