Viewing 26 posts - 1 through 26 (of 26 total)
  • Ground anchor, what have I done wrong?
  • DT78
    Free Member

    Fitted a Oxford ground anchor today. Drilled the hole to the right depth and diameter, hammered the metal sleeves flush, then screwed In the hex bolts, but could not get them all the way in, very stiff, so used an impact driver, managed to get them a little further in, but cannot get that last half a cm, so leaves enough space to try and pry it away. What have I done wrong? Followed the instructions? Are the metal sleeves not expanding properly?

    leffeboy
    Full Member

    Are you sure the hole is the right depth?

    carlos
    Free Member

    The hole needs to be the length of the anchor + some extra for the bolt to be drawn through into. Say for example it’s a 100mm anchor, drill a 120mm hole otherwise the bolt has no where to go when screwed through, if you whizz the bolt through the anchor in your hand you’ll see what I mean

    Hope that makes sense.

    Carlos

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    cloudnine
    Free Member

    Dusty hole.. did you get the dust out of your hole before inserting the bolt

    choppersquad
    Free Member

    I would agree with cloudnine.
    Probably a shed load of dust in the hole?

    DT78
    Free Member

    I drilled to just past 65mm as per instructions. Bollox I didn’t think to blow the dust out. Anything I can do to rescue or do I need another pair of plugs?

    leffeboy
    Full Member

    Can you remove the bolts and blow the dust out using a straw or is the anchor too narrow?

    carlos
    Free Member

    https://www.concretefasteners.com/how-to-install-sleeve-anchors

    You might be lucky with a vacuum cleaner to suck out the dust, but if it’s not deep enough…?

    lerk
    Free Member

    Now you have them set, chop 5mm off the end of the bolt.

    DT78
    Free Member

    I’ll give the vacuum a go in the morning. Nothing in the instructions about removing dust *grumble*

    revs1972
    Free Member

    unusual to have that amount of dust in the hole (if the hole is 65mm deeper than the bolt)

    Did you have the bolt inserted into the sleeve when you knocked it in ?
    From your description it sounds like you hammered the sleeves in flush without the bolt in them….

    spooky_b329
    Full Member

    If you just put the bolt in a few turns, can you lever the sleeves out?

    DT78
    Free Member

    Instructions said to drill to 65mm, and yes hammered in without the bolt in….didn’t mention that on instructions either. Could I run a smaller diameter bit through the centre to get that last 5mm is if the vacuum doesn’t sort it? Probably nothing to lose as if it doesn’t fit now way of getting the plugs out now 🙁

    neilwheel
    Free Member

    If they are sleeve anchors then you should be able to get them to unseat. Back the bolt off a few turns, give the head a gentle tap, this will drive the expander cone back down. Repeat this and keep giving them a wiggle until they can be lifted out.

    Post a stock pic of the type of anchor bolt if you like?

    As above, you could remove the bolts, blow out the dust, and if you need to, trim a bit off the length to get it to sit down properly.

    revs1972
    Free Member

    I don’t know if it makes any difference as i dont know the science behind them , but ive been taught that you should always have the bolt in the anchor when knocking them im. ( ive put a shed load of these in ).
    First thing I would do is use something slightly smaller than the bolt hole to poke down to double check the depth ( a pencil may be thin enough).
    Check that against the bolt length.
    My thinking is that something in the sleeve has contracted , thus not allowing the bolt to push though ( having the bolt in when installing would stop this happening)

    FuzzyWuzzy
    Full Member

    Careful when you blow the dust out of the holes, I made the mistake of not closing my eyes doing it whilst fitting my ground anchor and yes using a track pump would have made more sense :p

    Greybeard
    Free Member

    It’s normal to put the whole assembly in together, and it shouldn’t need hammering. The wedge/cone at the bottom may have tilted slightly, so the bolt has cross-threaded. That would explain it being hard to turn.

    neilwheel
    Free Member

    If the hole has not been cleaned there will be enough friction from dust to require a hammer to fit the anchors.

    OP best bet is to pull the bolts and inspect the threads, if they look good, then try to save these anchors. Use something like an old spoke or a skewer to break up the dust in the bottom of the hole, it will be compacted now. Blow or suck out the dust, measure hole depth and compare to the bolt length, you should also be able to feel how deep the cone is set too. If you need to cut down the bolt, do a nice cut and put a chamfer on the end, make sure the thread is clean and free from burrs.

    If all this fails, then don’t go and drill new anchors next to these ones, when you fits the second set, the force might crack through and it will not be secure.

    If you have mangled the bolts and they cant be removed then the last option would be to fill the gap under the ground anchor. Clean out any dust then pumping in some resin for fixing studs in masonry. It will set rock hard and bond to metal and masonry.

    Like these, check but should fit into a normal cartridge gun.

    Resin
    Resin

    ransos
    Free Member

    I used a vacuum to clean out the holes when installing mine – the sleeves went in with a light tap.

    DT78
    Free Member

    Grey beard was right, the cone one one had twisted, and cross threaded. As well as the dust compacting issue. Managed to get one sleeve out which then fell apart. Cleaned out dust and shortened slightly. Fits better but still not happy about it, the broken sleeve can be wiggled given enough force, so I’ll probably use some of that resin to secure it.

    Checked the instructions. Definitely does not mention removing dust and images show knocking the sleeve in with a hammer without a bolt in it. Tempted to have a moan at Oxford, not on really there was no mention of two pretty important things

    nickdavies
    Full Member

    I fitted one the other day, right nightmare. Instructions were non existent, had to get them off the internet and followed them to the letter, right lengths, diameters etc. The only thing I didn’t check was the bolts and sleeves – they came put together and the instructions said knock them in to the wall together, so I did. 1/2 hour of cursing later and no joy I managed to get them out, they were a mess so I took them back to b&q as I thought they were just crap and I was a bit miffed having bought 2 expensive drill bits to install them.

    Offered an exchange or a refund, was pointing out I’d like an exchange but not if they were all that bad quality when the bloke behind me at the till pointed out the sleeves were on backwards…. 😳

    neilwheel
    Free Member

    Ignore the second link that I posted, you need a specific gun to use that one.

    Read the instructions………….

    It’s a two part resin which is mixed in the nozzle, so they are one use only, you might want to buy a spare nozzle or two. Remove the nozzle from the cartridge, clean the end and put the cap back on to save the rest for further use.

    craigxxl
    Free Member

    My ground anchor kit came with resin capsules. I’d never used them before but they’re almost idiot proof. If the concrete/brick is solid then I highly recommend them.
    Resin Capsules

    bencooper
    Free Member

    Depends on the anchors – some are better to be hammered in without the bolt, because if you hammer the bolt then the captive cone can pop off the end, rather than pulling the sleeves into the hole. Hammering the top of the sleeves to get them in works better and the cone os captive so won’t fall off anyway.

    I fitted about two dozen of the things last weekend to build this thing:

    No vacuum to clean out the holes, just wiggle the drill bit until most of the dust is gone.

    bodgy
    Free Member

    @bencooper – how’s the community garden coming along?

    bencooper
    Free Member

    Not bad – got some more raised beds to build, but this was the big construction project – it’s going to get lots of stuff growing up it. Still got to build a green wall on the side of a 20ft container.

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