Adding a Fixture to a Concrete Slab

Redjeep!

Hi,

This is probably a dumb question, but please bear with me.

I want to add a ground anchor in a shed with a concrete slab base. The ground anchor is going to be a hardened steel ring that I can feed a chain through and use to lock down a bike.

Now, I don't want to drill the concrete as I'm worried it will break through the damp barrier and I'll get damp problems in the shed, so can I just cement it down to the base with cement ? Will the new cement stick to the existing slab enough to stop somebody breaking it off ?

Joey the lips

No not as far as i know you cant addin concrete but how deep is your floor???? but if its a shed why dont you fix something to the wall. If they get that far you can bet they will prob have a bolt cutters to cut the chain!

Redjeep!

The slab is very thick, about 8 inches, but there's obviously been problem with damp in the past as the top surface is a 2 inch thick slab that's laid on top of a 6 inch slab with a damp barrier between them. I don't want to drill through the damp barrier as I think it'll allow the water to creep up into the top slab. The ground it's sat on is very damp.

The walls are steel. Only the base is concrete. I've got a hardened steel chain and padlock and just want to mount a thick steel ring or length of box section to the slab.

I know all the arguments that 'if they want it, they'll take it' etc, but I still want to make them work for it.

slavetothegrind

2" aint much purchase for bolts, i'd say your best bet would be a chemical anchor.
You drill out down to say 13/4" ( use depth stopper on drill) clean out hole and insert chemical as per instructions then push in threaded anchor bolt.
It sets in an hour and is strong as anything, get it from Hilti, any hilti store will advise and supply.

Use four of them and then i'd say the chain is the weak link ( geddit:P)

Then when parking bike for the night disconnect battery and connect phase direct from 63amp supply and blow the thieving toerag thief the fcuk out of it!

Or maybe not.......:rolleyes:

Joey the lips

My apologies, you are in a difficult situation,

3dsteel

Here's an idea: if you got some 100mm long anchors, drill them into the slab 30 - 40mm leaving the rest sticking up. You could then pour your new plinth on top of them. The anchors would act like dowels for your new plinth. Before pouring, you could roughen the existing floor with a chisle (or kango ) to provide a key for the new plinth.

Joey the lips

Here is an idea, fill 2 flower pots with cement and put the anchors in them! they will be mobile but not very. Dont fancy moving the pots with the bike!

Redjeep!

Thanks guys, plenty to think about there. I'd thought about using a couple of containers full of concrete and may still do it, but am worried that the thief could put them on a trolley or something and just carry the whole lot outside into a van.
Pouring the cement around the anchor bolts would also work well. I'll find out about the chemical anchor as well as it may be that that would keep the dampproof membrane intact by plugging the hole.

Thanks again.

cork1

if its a steel shed why not bolt an anchor on top the frame?