Bolts for tarmac

[MadeFromPotatoes]

I’m hoping @PigletJohn is around 🙏🏻. I’m buying a couple of these posts.. They’re going into sound tarmac but the bolts mentioned in accessories say that they’re not for tarmac.

The bolts are described as 2x16mm. I can find tarmac bolts elsewhere but I can’t see any that are 16mm.

Can anyone help with finding the bolts I need. Thanks a lot.

Bolts are not ‘threaded’ into tarmac, so there is no tarmac bolt.
I was going to advise installing a concrete padstone with the holes pre-created, however a quick look on YouTube reveals what the professionals do:

Interesting, I’m hoping to use something like this. Lots of other options are sold with tarmac bolts. I need this design so I can use a chain in between, without the added expense of the eyebolt posts.

So those bolts have something inside them to expand and make the plastic sleeve behave like a raw plug.
You drill a 23mm hole ( though they say sizes vary ) about 12cm into the tarmac, push these in, locate post, insert bolts and tighten.
Having had plenty of raw plug issues over the years ( never tried tarmac before ) I’d favour the YouTube guys approach though.

Thanks, I don’t want the hassle of the YouTube guy’s method.

Is the 16mm on the post listing a red herring then?

Did you read the instructions?
www.barriersdirect.co.uk/system/product_assets/paperclip_files/000/044/945/original/AUTOPA_Hinged_Parking_Post_Instructions.pdf

Actually recommends installing on a concrete block. The tarmac bolt is a compromise.
I don’t see YouTube guys approach to be difficult, and in fact you will get certainty, they fit them day in, day out and can’t afford to waste time or recalls.
The fixing holes are 18mm diameter. So a 16mm threaded rod is all you need, and a big drill bit, bigger than 16mm so you can get the resin in there. Maybe 21 or 22mm.
Here are the rods:
www.screwfix.com/p/easyfix-bzp-steel-threaded-rods-m16-x-1000mm-5-pack/69529

You’ll need a disc cutter to cut to the correct length after you’ve drilled the holes.
Anyway you’ll have to hire a proper drill, a household one most likely won’t work.

You are better off putting in a concrete pad for the posts. Tarmac is too soft to provide a long-term sturdy support.

Agreed. Tarmac is not suitable. On a hot day it is as strong as a fruitcake.

I did read the instructions but also read the instructions for all those that are bolted into tarmac. It’s just to stop cheeky people parking on my in/out drive and turning round in it, or even, as last week, putting a skip on it!

I’ll be asking my builder to put them in. The YouTube guy’s method looks very permanent whereas I would take them up when I move later on in the year.

Workplace Depot have got videos of them being secured to tarmac but I can’t seem to link.

I just want the cheapest, easiest to remove in a few months option as a deterrent.

When you remove the posts, you just use a disc cutter to cut the protruding bolts off.
Have you tried traffic cones yet?

Yes, I've tried cones, waste of space, the skip was the final straw. Disc cutter = another job for my builder whereas bolts is something I could take out.

Obviously I get that the other method is better but there are so many of these kits available for bolting into tarmac it must be a reasonable and easier solution. I don't want security, just a deterrent.

If you screw it into tarmac, it will probably pull out if someone kicks it

Or possibly bumps it with a pram.

The pillar gives tremendous pull-out leverage.

The resin injection is gluing the studs into the (hopefully) consolidated crushed stone or rubble base beneath.

Though I would be more confident in a concrete block.