Home & Garden

Need help with question on base for interlocking and pergola

  • Last Updated:
  • Jun 20th, 2017 11:07 am
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes

Need help with question on base for interlocking and pergola

Hello, we are planning to do interlock ourselves on an area of ~2000 sq ft ( walkway and patio) and have a few questions below. Hoping someone can shed some lights into this as well as sharing your experience. Much appreciated!!! We are located in east end Toronto
1) since the area is quite large, where can we buy reasonable price and quality geotextile and HPB. I heard it that it is cheaper at aggregate yards than garden centers or landscaping places..
2) we are thinking to build 6 inches base. Is this sufficient for walkways and patio?
3) can we make 3 inches of granular A crushed stone and 3 inches of HPB as we heard that HPB is more expensive? Or we have to build 6 inches of HPB
4) Also we want to a pergola as well on the interlock patio. The size is 16Wx16Lx12H ft we are thinking. How many posts do we need. Do we have to pour concrete for the base and how thick is needed?

Many thanks...
23 replies
Member
May 28, 2017
204 posts
62 upvotes
1 post every 8 ft would be fine. What you can do is dig a hole at least 4 feet then put in 1/2 bag of cement and level it down. Then put your post in there and fill with gravel.
Deal Fanatic
User avatar
Nov 19, 2004
8700 posts
1694 upvotes
Cambridge, ON
If the pioneers is going to extend to the pergola posts, put the posts in first since you will need to dig the holes below the frost line and bury the posts. For a 12' high pergola, you are going to need 16' posts since approximately 4' will be below ground.

Even if the patio is going to be within the post perimeter, I'd still do the posts first just to avoid any mess once the patio is in.

As for depth, you will get all sorts of responses. I think we did ours 6-8" (slope to account for). Good enough for a patio. I'd just use hpb for the whole thing.
Deal Addict
Dec 17, 2007
2025 posts
1005 upvotes
Alliston, ON
You should go minimum 8" deep for the interlock. 3" base of granular A, tamp it, then the rest HPB tamping it every few inches.

Don't forget to take into account the height of your pavers when you dig. If the stones are 3" thick and you only dig out 6", that only leaves you with a 3" base. It's better to go a bit deeper when you dig it out now, then have stones shift in a few years and wish then that you had gone deeper.
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
don242 wrote: If the pioneers is going to extend to the pergola posts, put the posts in first since you will need to dig the holes below the frost line and bury the posts. For a 12' high pergola, you are going to need 16' posts since approximately 4' will be below ground.

Even if the patio is going to be within the post perimeter, I'd still do the posts first just to avoid any mess once the patio is in.

As for depth, you will get all sorts of responses. I think we did ours 6-8" (slope to account for). Good enough for a patio. I'd just use hpb for the whole thing.
Thank you all for your insights.
@don242 "If the pioneers is going to extend to the pergola posts..." could you please elaborate as i am not sure I understand this :-(

Any ideas where to buy the geotextile and HPB with reasonable price? Thanks
Deal Fanatic
User avatar
Nov 19, 2004
8700 posts
1694 upvotes
Cambridge, ON
tockty wrote: Thank you all for your insights.
@don242 "If the pioneers is going to extend to the pergola posts..." could you please elaborate as i am not sure I understand this :-(

Any ideas where to buy the geotextile and HPB with reasonable price? Thanks
Sorry, that should have read "patio", not "pioneers". Bad case of auto correct.

I can't remember how much hpb we got, but the price varied based on amount. We paid $255 delivered for up to 11 cu.yds. from a garden center, but we are in Cambridge so not sure of places in your area.
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
don242 wrote: Sorry, that should have read "patio", not "pioneers". Bad case of auto correct.

I can't remember how much hpb we got, but the price varied based on amount. We paid $255 delivered for up to 11 cu.yds. from a garden center, but we are in Cambridge so not sure of places in your area.
Thanks for your prompt response! Would you use 4x4 or 6x6 for the post?
Deal Fanatic
User avatar
Nov 19, 2004
8700 posts
1694 upvotes
Cambridge, ON
tockty wrote: Thanks for your prompt response! Would you use 4x4 or 6x6 for the post?
I'd definitely go with 6x6 posts. Our pergolas are much smaller and we still used 6x6. A bit more cost but you will definitely appreciate it after.
Sr. Member
Jan 3, 2013
534 posts
176 upvotes
Winnipeg
A 12 ft Pergola with 4x4 posts would be a death trap especially on a windy day.

Have you considered putting the posts on ground hogs? Here in Winnipeg if you buy four or more they're each $146 supplied and installed for 8ft deep.
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
zeon64 wrote: A 12 ft Pergola with 4x4 posts would be a death trap especially on a windy day.

Have you considered putting the posts on ground hogs? Here in Winnipeg if you buy four or more they're each $146 supplied and installed for 8ft deep.
Thank you all for the feedbacks
@zeon64 this is the 1st time I ever of this :-( you meant this one, right?Image
Can you please share pros and cons between the post buried in cement 4ft in the ground vs groudhog anchors? Many thanks
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
if we are going to bury the 6x6 posts into concrete 4ft deep underground. What is the diameter of the concrete that we should pour. As well, should we use sonotube for this?
Deal Fanatic
User avatar
Nov 19, 2004
8700 posts
1694 upvotes
Cambridge, ON
tockty wrote: if we are going to bury the 6x6 posts into concrete 4ft deep underground. What is the diameter of the concrete that we should pour. As well, should we use sonotube for this?
I'd go with a 10" diameter hole. Don't bother with sonotubes for this. Gravel at the bottom of the hole, put in post and add concrete.
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
don242 wrote: I'd go with a 10" diameter hole. Don't bother with sonotubes for this. Gravel at the bottom of the hole, put in post and add concrete.
Thanks so much don242! do you know any lumber yards in east end toronto other than typical big box such as HD, Rona. I am sourcing materials for the pergola as well as garden shed. We like the cedar for the pergola and pressure treated wood for shed. I had called Lumber guy and central fairbank lumber but they said they don't stock the cedar. I am not sure if we should go with PT wood for both pergola and shed?
Deal Addict
User avatar
Feb 10, 2006
3192 posts
480 upvotes
From your base standpoint, I would opt for just using HPB only. The cost difference shouldn't be too much per yard . Definitely source your material from a stone yard if possible. You may be even able to swing a cash no tax kind of deal, atleast that was openly available for my purchase. In terms of Geotextile fabric, I would get that from a landscaping yard (Arnt's is an example by me, but I am sure you have other options).

A 6" base is more then sufficient for a walkway/patio. I do know that the interlock manufacturer's may suggest a deeper base depending on your soil composition (sandy or clay).
[OP]
Member
Sep 7, 2008
280 posts
3 upvotes
azn_dan wrote: From your base standpoint, I would opt for just using HPB only. The cost difference shouldn't be too much per yard . Definitely source your material from a stone yard if possible. You may be even able to swing a cash no tax kind of deal, atleast that was openly available for my purchase. In terms of Geotextile fabric, I would get that from a landscaping yard (Arnt's is an example by me, but I am sure you have other options).

A 6" base is more then sufficient for a walkway/patio. I do know that the interlock manufacturer's may suggest a deeper base depending on your soil composition (sandy or clay).
Thanks! we are looking at permacon and they recommend between 6~8 inches base if i recalled. We are planning to buy 80mm thick pavers for driveway as the style we like have biggest piece of 19 1/2 x 13 inches. Should we also use the same thickness for patio and walkway as well or we are good with 60mm for the same style.

Top