Help: Projecting Anchor Bolts

[Gary]

I've purchsed some projecting anchor bolts to enable me to put a heavy load on a wall (TV to be precise).

As I'm a complete newbie at DIY I drilled the first 16mm hole this evening. I then proceeded to put the anchor bolt into the hole. The problem I found was that the thicker end of the anchor bolt would not go fully into the hole and I ended up having to use a hammer to knock the bolt in. I'm certain this can't be the right way. So was wondering if anyone could give me some advice on how I'm supposed to install anchor bolts.

The type of bolt I'm talking about can be seen here.

for any help

Gary

[paul]

could be a couple of things but....

sometimes the hole will be filled with dust and bits of brick/plaster that just restricts the bolt from going in, try running the drill for a few seconds after you drill the hole and pull it in and out or use a hoover on it.

Paul

[Colin Wilson]

You could always waggle the drill in the hole to open it out a little - with this type of fixing it doesn`t really matter, as the fixing expands almost indefinitely to fill the hole as the bolt acts on the cam that forces out the wings.

You also get a little play on lining up the holes that way too :-}

[Cicero]

============ It's possible that the expanding part is already partly expanded. Make sure that you slacken off the nut before inserting the bolt.

Cic.

[Frank Erskine]

Many years ago I bought a rubber bulb from Hilti for this very purpose. It had a thinnish plastic pipe attached which you simply poked in the hole and blew the swarf out.

Actually Rawlbolts are better than sleeve bolts inasmuch as you can get away with a slightly larger hole than the nominal, since there's quite a bit more expansion (and the walls are serrated to give a better grip).

[Stefek Zaba]

The critical bit of info you need to give us is what material you're drilling these holes in. "Real" brick will be fine (if you're lucky enough to avoid the mortar between the bricks!) and provided the plaster isn't outrageously thick. Plasterboard would be an utter disaster. Lightweight concrete blocks (v. often used as the inner skin of outer walls on recently-built houses) won't hold an anchor bolt too well.

Since your TV (plasma screen? or big heavy 'normal' (cathode-ray tube)) is a serious weight, it's going to be a Good Idea to get whatever form of anchoring is most suitable nice and secure!

Stefek

[Dave Plowman (News)]

IIRC, the collar part is meant to only sit flush with the plaster to give a neat finish as well as help holding it together until tightened, so a tap with a hammer to get it to fit is ok. It's the cast steel bits that spread when you tighten it to take the load.

If going into an unplastered brick wall made of hard bricks you might need to enlarge the start of the hole to get it to fit flush.

[Ian White]

A large bendable drinking straw does the trick.

Large and bendable so the dust doesn't come right back at you... and remember to blow, not suck.

[Colin Wilson]

Good point :-}

[Dave Plowman (News)]

16mm will not be a million miles away from the mortar between two courses. Just make sure the wedges on the bolt are top and bottom as you tighten it.

[Gary]

The TV is a plasma (35kg), and I'm recessing the bolt into the hole. The bolt is 135mm so I drill a hole 125mm deep, the sleeve sits way back in the hole and the actual bolt then petrudes the full 135mm from the back of the hole giving approx 10mm I can attach the nut to. Is this correct.

I'm going into breezeblock through plasterboard that's been tab and dabbed (sp?) onto the breezeblock. The bolt then opens up inside the breezeblock. This is an exterior wall in a 3 year old house.

Comments appreciated.

Thanks

Gary

[Tim Mitchell]

In article , Gary writes

No, the front end of the sleeve should be flush with the wall, you should drill the hole to the depth of the sleeve only (plus a little bit). When you tighten it up, the bolt will pull out of the sleeve (opening it up and fixing it) so you'll end up with a lot more bolt sticking out. If the protruding bolt is a problem, cut it off with an angle grinder after fixing.

[Pecanfan]

Everything everyone else said, and one other tip - if the bricks / blocks you're going in to are vaguely near the edge of a wall, don't over-tighten the bolts! They'll happily break bricks clean in half.

Andy

[Ian Middleton]

I have seen the resin anchor system be used to hold a 25inch TV stand to a breeze block and plasterboard wall. The resin "spills out" in the gap between the breeze block and plasterboard providing a solid backing to the plasterboard when the stand is tightened to the wall. I think it was a PlasPlugs kit from B&Q used.

[Gary]

If I get the sleeve flush to the front of the plasterboard the sleeve won't be deep enough into the wall to be into the breezeblock, this would be the problem. These are also the largest bolts I found (length wise).

I now have one bolt in the wall as described in my earlier post. Is there anything I could use to fill the gap whilst still using the bolt as secured?

[Stefek Zaba]

The problem, as I see it, is that you have this gap between the breezeblock wall (which we'll pretend is 'strong' for current purposes!) with a bit of air followed by the plasterboard. The plasterboard's not very far off the breezeblock, is it - what, half an inch or an inch, the thickness of the dabs, right?

For a firm fixing, I'd want to bridge that gap with something more solid, or attach the brackets which holds your TV up flat against the breezeblock itself. Suitable 'packing' might be: wood offcuts, the car-body-filler that at least one of our regulars is always keen on, or similar gubbins. One other poster's already suggested losing the sleeve anchors and using the polyester-resin-and-studding approach, which would be OK if you can spread the load onto a large enough area of the more-or-less-unsupported plasterboard left at the front.

HTH - Stefek

[Gary]

Due to the cost of the TV and generally that I'm now unhappy doing this myself I'm going to see if I can get someone in to do the job. I've been quoted £300 to do the job of mounting the plasma, rather high I think but a price I might have to live with.

Just need to figure out how to remove the one bolt I did put in place, that seemingly doesn't ever want to move, and thats before I tightened the nut to expand the sleeve!!

Thanks

Gary

[Colin Wilson]

Tap the stud in the middle, and try to waggle or prise the outer sleeve out - if you can get onto it with pliers or grips of some sort, then as long as you`re not pulling on the stud itself you`ll get there :-}

[Dave Plowman (News)]

Ah. Didn't pick up it was plasterboard.

The bolt must bear solidly on the block face to work - pulling on plasterboard just won't do. I'd feel inclined to make up wood battens slightly wider and longer than the bracket to the depth between the plasterboard face and the blocks and cut them in. Make the holes the same size as the threads so the anchors are kept flush with the blocks. Then when you tighten them, the full strain will be on the blocks.

[Ian Middleton]

Actually thinking about it, what I did in my last house for the TV holder on a breezeblock and plasterboard wall, was cut a hole in the plasterboard the size of the bracket. In the hole I screwed to the breeze block exact shaped

18mm +6mm MDF. This ended up with the MDF being almost flush (slightly lower but good enough) with the plaster. I then filled edges and painted and used expanding fittings in the breeze block to hold the bracket to the wall.

I have also seen a house where two large (floor to ceiling and width of plasma screen) sheets of MDF/block board where screwed/bonded to the plasterboard and plainted the room colour. The plasma screen attached to this sheets. I think the rear sheet had a section missing so you could feed cables down the back and they appear at ground level. Looked OK if you don't mind raised section of wall and missing section of skirting board and something strange to leave the next purchasers of the house.