drilling into paving slabs

[gaz2923]

complete newbie question so i apologise in advance

I am building a lean to shed for my motorbike and want to secure the frame to my very solid patio

i have a cordless hammer drill and a 240v non hammer drill, the cordless doesnt seem to have the juice and the non hammer drill has just left me with a rounded drill bit

do you need special bits to drill into flagstones or will i just need to use a 240v hammer drill?

i am going to use brown plugs once i have the 7mm holes in there as i dont fancy shelling out for expensive anchors, any tips?

 

[simon_m]

Borrow a decent SDS drill if you can, this will make light work of the job. I would think about using a more robust fixing than brown plugs though.

 

[gaz2923]

what kind of fixing would you recommend?

i am building two sides of the shed and using an existing wall and an existing fence as the other parts (its for weather cover rather than security)

i was going to fix the one side down to the slabs with screws rather than use a metpost or anything like that

the frame is being made out of 75mm fence posts that i have spare

 

[simon_m]

Difficult to say really, a paving slab is not very thick and they also crack easily. I was thinking of frame fixings but even the smallest ones will be useless. The problem with an anchor fixing is it will probably just crack the slab, so I guess you are pretty much stuck with using rawlplugs.

Rather than security issues I was thinking more along the lines of it blowing down in strong winds, it wouldn't take much to pull the plugs out. If the area is sheltered you may be OK.

 

[gaz2923]

can you screww straight into concrete slabs, im sure i have seen concrete screws before on ebay

 

[simon_m]

can you screww straight into concrete slabs, im sure i have seen concrete screws before on ebay

These will probably break the slab

 

[^woody^]

Any rawlplug, framefix, or expansion bolt will do. Screwfix sell some screws with require no pugs - 'multi-monti' or similar

The self weight of the lean to is going to hold it down, and all the bolts will be doing is preventing sideways movement. I cant see it going nowhere even with lightfixings.

An SDS may be too powerful and could crack the slabs, so if using one start with a thin bit (5mm?) and then use a bigger one of the required size

 

[Deluks]

Replace a couple of the slabs with a hole filled with postmix. Stick a couple of restraint straps to the frame and into the 'crete.

 

[gaz2923]

thanks guys, im going to borrow my mates 240v hammer and see if that gets through the slabs

ta

 

[JohnD]

you can drill through a paving slab easily enough, but it will not give you a secure fixing (as the slab might crack, especially if someone wants it to). you would do better to drill into the concrete underneath, If there isn't any, take up a slab and dig a hole and cast a nice big lump. You can embed a heavy chain into it if you want, or a big ringbolt. Scaffolders ringbolts are quite cheap.

 

[gaz2923]

tha slabs are concreted down very firmly as it is near to a manhole, i am reluctant to take them up to be honest

 

[noseall]

agree with the guys ref. fixing.

a plugless anchor is less likely to crack the slab as it grips the masonry by the thread as opposed to an expansion type fixing.

it is drilling a damage-free hole in the first place that is going to be difficult.

try these