Pergola Post Base

[kzaji]

Hi, I'm planning to build a 3x2m pergola, with 4 150mm green oak posts, and despite googling for days can't come to a conclusion with how to anchor the posts.

The wife doesn't want me digging in the area as there's an oil line running under it but there is an existing concrete base where it's going to go.

So then I start looking at options that don't include digging and I see a bunch of sketchy looking ones on amazon and then these Framola Brackets https://www.indooroutdoors.co.uk/products/framola-pergola-post-base-bracket?variant=32428626018378 - They sound alright and the company seems decent but can't really find any reviews of them etc. Anyone used them to anchor posts? What do you think?

Then I came across a bloke on youtube using these https://www.roundwood.com/product/granite-tapered-square-staddle-stone-with-iron-pin/ with nothing but a slot for that little pin in the bottom of the post. Are these really enough or is there something I'm missing?

Any other suggestions?

 

[Bingy man]

Both of those options rely on your base being level not to mention the cost per post . These are a set of 4 and they are adjustable..

4PCS 100-150mm Galvanised Adjustable Elevated Post Base Support, Heavy Duty Roof Support for Building - Black
£26.99
Amazon.co.uk

 

[ChaiLatte]

Both of those options rely on your base being level
4PCS 100-150mm Galvanised Adjustable Elevated Post Base Support, Heavy Duty Roof Support for Building - Black
£26.99
Amazon.co.uk

I am a simple person. If my base is not level, I just cut off a bit at the top of whichever post is higher so they become the same.

I am also a simple person: I just shim under whichever base is lower until it is the same as the other.

----

To me, the Framola ones look ugly. I would want a skirting around them once installed. The concrete slab needs to be deep enough to fasten them down without the screws penetrating the oil line.

To me, you have more chance of hitting the oil line if you drill a random hole somewhere above it than if you carefully excavate near to it. But that is why I am not your wife.

The saddle stones look nice. The pin does seem a little short. As they appear made to order, you could enquire about a longer pin. For the price they are charging, it is sheer meanness not to use a stainless pin. If you do but them, give the pins a generous coat of zinc galvanising paint.

As long as there is no uplift on the pergola, the weight might be enough to keep everything in place.

As your proposed posts are 150mm square, there is plenty of room for you to drill a couple of additional holes in the granite and glue in some longer stainless steel pins (stainless threaded rod is available from Screwstation or Toolfix). A couple of 10mm diameter pins projecting 100mm and glued into the oak (with a hybred silicone, e.g. Stixall) would enable you to hold the post and lift the stone off the ground.

 

[Cabinetman]

You could do it the Japanese way by scribing the bottom of the post to some supporting rocks?

 

[Tris]

This type of thing should work well

https://www.ebay.co.uk/itm/22327933...ar=523209778947&widget_ver=artemis&media=COPY

 

[Ollie78]

I looked at the framola ones but they seem to be like a cup that will hold water in the base. I am considering these from Vevor
https://uk.vevor.com/deck-post-base...upport-decorative-anchor-plate-p_010704528560

They might be rubbish but they are stainless steel and keep the base off the floor. I might order some and send them back if they are rubbish, they are the cheapest solution I can find.
We already have a concrete base and will be constructing a large car port with 150mm posts.

Or something like the simpsons strongtie ones with the slot method
https://www.strongtie.co.uk/en-UK/products/concealed-post-base-cpt
They have a few options actually.

I have seen people cast a small concrete pad for each post and just set in a bit of stainless threaded rod ( with a bend to keep it stuck in the concrete) then you can locate the post in the pin. So its like a mini footing raised a bit off the surface.
This is quite common in deck building.

You could in theory drill and chemical anchor a stainless threaded bar into almost any saddle stone type.

Ollie

 

[Phill05]

How about these:

 

[Ollie78]

How about these:

View attachment 183211

OOh they are fancy

 

[Stigmorgan]

If you already have a solid base these work well
https://www.kebur.co.uk/product/fencemate-bolt-down-post-supports/

I've used these and the drive in ones before and they work fine.

 

[ChaiLatte]

If you already have a solid base these work well
https://www.kebur.co.uk/product/fencemate-bolt-down-post-supports/

But they sure are ugly. Bollards to those, or more precisely, Blackwood Bollards

(https://www.blackwoodoutdoorliving.co.uk/post-bases/)

 

[Doug71]

I think the slot type look the most aesthetically pleasing and are what you tend to see on higher quality work.

 

[kzaji]

I am a simple person. If my base is not level, I just cut off a bit at the top of whichever post is higher so they become the same.

To me, the Framola ones look ugly. I would want a skirting around them once installed. The concrete slab needs to be deep enough to fasten them down without the screws penetrating the oil line.

To me, you have more chance of hitting the oil line if you drill a random hole somewhere above it than if you carefully excavate near to it. But that is why I am not your wife.

The saddle stones look nice. The pin does seem a little short. As they appear made to order, you could enquire about a longer pin. For the price they are charging, it is sheer meanness not to use a stainless pin. If you do but them, give the pins a generous coat of zinc galvanising paint.

As long as there is no uplift on the pergola, the weight might be enough to keep everything in place.

As your proposed posts are 150mm square, there is plenty of room for you to drill a couple of additional holes in the granite and glue in some longer stainless steel pins (stainless threaded rod is available from Screwstation or Toolfix). A couple of 10mm diameter pins projecting 100mm and glued into the oak (with a hybred silicone, e.g. Stixall) would enable you to hold the post and lift the stone off the ground.

Yeah I'd planned to just level it at the top, but the base is pretty level really, I don't think I'd need much. I didn't look at those adjustable ones because I dunno, looked a bit suspect online though I've never seen them in real life.

And yeah I'd planned to add a timber skirt at the bottom if using those Framola, or any of the other visible brackets. They do a cover but it still looks bad.

I didn't consider that regarding drilling down, how big do you think the bolts would/should be for brackets like framola? I think they recommend 60mm bolts or something. Again seems short, not sure how deep the current base is will have to check. Good idea.

Can you elaborate on what you mean by uplift please mate? I'd read that the weight should be enough but has me nervous not having it secure solid.

I might contact those post people then as you say and at least see how far it sticks out, doesn't seem far does it.

Thanks

 

[kzaji]

You could do it the Japanese way by scribing the bottom of the post to some supporting rocks?

I've seen those! They look amazing but not something I'd even bother attempting

This type of thing should work well

https://www.ebay.co.uk/itm/22327933...ar=523209778947&widget_ver=artemis&media=COPY

Yeah they look alright don't they, have you used them, solid?

How about these:

View attachment 183211

They are really nice, is it easy to add pins yourself? Where'd you find them? Though I'm guessing they're pricey!?

But they sure are ugly. Bollards to those, or more precisely, Blackwood Bollards

(https://www.blackwoodoutdoorliving.co.uk/post-bases/)

Some solid stuff on there to consider, nice one

I think the slot type look the most aesthetically pleasing and are what you tend to see on higher quality work.

I'm going to cover the fixings for sure anyway mate, don't really mind how it looks underneath.

 

[ChaiLatte]

Can you elaborate on what you mean by uplift please mate?

Consider this: the pergola is very lightly built, and then, let us say, you decide to put some kind of fabric shade under it to keep the sun off your smoked salmon sandwiches and champagne.

What happens if the wind blows strongly? The fabric can act as a sail and try to lift the whole pergola like a giant kite. If there were some foliage-dense climbing plant growing on it, that can also act as a wind-catcher.

It is a very unlikely scenario especially as I do not know how you will construct it nor how you will use it. You have to ask yourself the question "is there any way the wind could try to lift this off the ground either as it is or if I do something to it in the future?" The answer is likely to be a strong 'no' but it is worth thinking about at construction stage.

You make design choices and they have implications. I have decided to choose a rope to connect myself to my dog - that will help it to pull me along, but will not be so good if I want to push it along. I have decided to make my pergola a gravity structure, so I should not add a sail to it if the weather forecast is for wind.

The second type of stone plinth shown might be easier to work with than the one with the pin in it already. You'd fix the pin into the wood (a stainless coach screw with the head cut off). Within reason, it would not need to be dead central nor perfectly straight. Fill the hole in the stone with your chosen glue (cement grout, stixall, car body filler) and erect the post. Align the post before the glue sets.

 

[Phill05]

They are really nice, is it easy to add pins yourself? Where'd you find them? Though I'm guessing they're pricey!?

A friend of mine has a stone company and he cuts them, he supplies them with stainless steel pins, you then need to resin them in to your posts and stone leaving a gap between post and stone.

 

[HOJ]

Having used the Simpson ones (with the blade type fixing) in the past, which in the end worked really well, I didn't like the fact we needed to cut a slot through the post.

My solution was to make jig for my chainsaw, which allowed me to plunge a cut into the base of the post, in effect making a making a mortice, so the end result didn't expose a cut in any of the faces of the post.

 

[Barkisland]

I used 150mm stainless steel dowels to pin the oak uprights on my garage. The weight holds everything in place and the dowel stops the posts sliding around

 

[Jamesc]

Similar to Barkisland I have used Stainless threaded rod, we get flooded every winter and it allowed me to raise the bottom of the posts off the ground. I drilled a hole in the bottom of each post and simply slipped them over the rods which I cemented in the ground. A simple nut and large washer have worked a treat. I know you are banned from digging into the ground but could you get away with a single hole for each post?

 

[ChaiLatte]

I used 150mm stainless steel dowels to pin the oak uprights on my garage.

Not necessarily aimed at you, but prompted by your post, there have been mentions above about water ponding at the bottom of the post and leaving a gap between post and stone.

Maybe we should consider the importance of this. The Japanese version is at the summit of the rock, so water cannot stay there. Would anything with a flat top need a spacer/shadow gap (e.g. stainless steel plate, maybe 10mm thick)?

I know you are banned from digging into the ground but could you get away with a single hole for each post?

In the Blackwood Bollards stuff, they have a little galvanised riser piece that can go inside a closed shoe to keep the post of the ground. Something similar could work, even a couple of M30 stainless nuts tossed into the shoe before the post goes in.

Then you use four short (50mm or 40mm) coach screws to bolt the shoe down, avoiding the pipe underneath.

I would try hard to find the line of the pipe and then hope it does not pass near to my posts. You can use bent coathangers for locating water. What do people in Texas use for oil-divining?

https://www.blackwoodoutdoorliving.co.uk/shop/lift-riser-for-post-bases/