Shield anchors

[milkman]

Anyone got any handy hints on using shield anchors? Had a lot of trouble getting them to tighten. Used the right bit for the size of anchor but still found them spinning in their hole. Very frustrating.

Cheers in advance.

 

[Static]

How large is the hole you've drilled for the bolt, and how big is the bolt?

 

[milkman]

They were M8x60mm and needed a 14mm bit.

Some of the bolts took and others didn't so maybe I need to refine my drilling skills.

 

[Deluks]

Bold down metposts by any chance?

 

[milkman]

Bold down? No.
Joist hangers into brick, well I say brick, funny white bricks, think they may have been some sort of cement composite things but thats another story

 

[Static]

Sounds like lightweight thermal blocks, if so no wonder they arent biting.
You may need to look at an alternative fixing.. What loading are you putting on them?

 

[JohnD]

Might also be sand/lime autoclaved bricks if they are brick-sized and it is not a modern house.

Sounds like the hole is too loose. Often happens. See if you can pack something to keep the plugs from turning. Once you've managed to tighten them up a bit they will grip the wall because the wedge will push it apart. You might even be able to expand it enough to grip by tightening the nut before you push it in.

I often use a slightly undersized drill if the bricks are crumbly, and try the fit in the first one before I drill the others.

 

[Nige F]

Bold down? No.
Joist hangers into brick, well I say brick, funny white bricks,

SANDLIMES

 

[milkman]

Thanks all for the advice. Its obvious when pointed out; its a hole, you stick an anchor in and it has to be snug enough not to spin when you tighten it. I tend to overthink these things and look for mysterious builder know-how rather than the bleeding obvious.

I've done the job and most of the anchors were fast enough. The loads on the joists are not great, certainly nowhere near the load from a floor for which these joists and hangers are designed. Its a storage space under a garage ceiling.

The bricks are probably the latter of your options. They were hard enough to warrant an SDS drill. I miscalculated the thickness of a walll and drilled right through. The stuff that burst out the other side looked like fine concrete more than any sort of brick.

Cheers once again.

 

[JohnD]

A woman would blame the anchor for being too small, but the real problem is that the hole is too loose