Need some advice please.

AV Monkey · 26-05-2008, 3:25 PM

I am going to wall mount my panny 46" when it arrives this week.
I have the wall bracket and just attempted to drill the holes.
The wall is an outside wall so was expecting to go through some plaster and board then find some kind of brick. I drilled an 8mm hole down to the lenght of the bit/flutes easy as anything around 80mm deep . I dont understand why i have not hit anything solid? The dust coming out is the same colour all the way. Apart from the first 1-2 mm which is a slightly different colour.
It just feels like plaster all the way in.
I have looked for a cavaty like you might find in a dot and dab but with a torch i can see the bottom and the sides of the hole look solid.
Really confused. Anyone got advice.

mossym · 26-05-2008, 3:30 PM

you didn't happen to drill right between blocks did you?

AV Monkey · 26-05-2008, 3:39 PM

Hi,

Should i try another one next to it?

mossym · 26-05-2008, 3:42 PM

nope, i'm only guessing so don't go drilling another hole just yet. you sure it's only the first 1-2 mil that are a differnt color?

AV Monkey · 26-05-2008, 3:46 PM

Yes the first 1-2mm like a thin pink layer then very light brown all the way. The house is about 15 yrs old

Badger0-0 · 26-05-2008, 3:53 PM

Sounds like plaster and then cement

Drill again.

AV Monkey · 26-05-2008, 3:55 PM

Shall i drill one at one of the other positions i have marked for mount?

mossym · 26-05-2008, 3:56 PM

Quote:

Originally Posted by Badger0-0

Sounds like plaster and then cement

Drill again.

what i was thinking, but glad you advised him to drill another big hole in his wall rather than me!!

mossym · 26-05-2008, 3:57 PM

Quote:

Originally Posted by andyhill

Shall i drill one at one of the other positions i have marked for mount?

how far away from the current hole is it? if it's the exact size of a block you may only hit cement again

Badger0-0 · 26-05-2008, 3:58 PM

The house is about 15 yrs old
I missed that.

It's almost certainly a cavity then.

Poke something thin into the hole and see if you wiggle it around.

You should be able to tell easily by just tapping the wall with your fist.
If it sounds hollow, it a cavity, which means you have to go deeper.

mossym · 26-05-2008, 3:59 PM

he said he could see bottom and sides of hole, doesn't sound like a cavity

AV Monkey · 26-05-2008, 4:02 PM

The holes i have marked for mount are about 38mm apart. thumping it sounds solid

Badger0-0 · 26-05-2008, 4:06 PM

Quote:

Originally Posted by mossym

what i was thinking, but glad you advised him to drill another big hole in his wall rather than me!!

I do it as part of my job

It'll be hidden by the screen anyway

and nowt a bit of filler won't put right.

mossym · 26-05-2008, 4:06 PM

Quote:

Originally Posted by andyhill

The holes i have marked for mount are about 38mm apart. thumping it sounds solid

38mm? that sounds awful close together!! for a 46" tv? you sure about those measurements?

Badger0-0 · 26-05-2008, 4:09 PM

Quote:

Originally Posted by andyhill

The holes i have marked for mount are about 38mm apart. thumping it sounds solid

Assuming that you're not dead unlucky and not just above a brick, that should be ok.
But just to be sure, go say 38mm to one side and down about 20 mm.
You should hit brick after a few mill. If you don't it has to be a cavity.

AV Monkey · 26-05-2008, 4:23 PM

Sorry ment 38cm apart.
Just drilled a second hole 14cm across and 8cm down from first one so wouild be hidden my bracket/tv. Same story again. First 1-2 mm pink(obviously plaster) then constant colour all the way down. Was very easy to drill straight in. Fine powder coming out very light brown.
Sides of hole very light brown cant see any cavity but easy to rub a groove with a small drill bit. Material crumbles easy when scrapped this way. Concrete blocks? powder is gritty.
Am i just expecting the brick to be harder?

Badger0-0 · 26-05-2008, 4:30 PM

It should be blindingly obvious if you're hitting brick.

Leaves you two choices, IMO.

1) Call a mate or neighbour, who's bit handy with the old DIY or,

If you don't want to do that,

2) stick one of the fixings in the hole, screw a screw in and pull hard with pliers or whatever. If you can't pull it out, you're sorted. If it comes out easy..........
revert to option 1)

Badger0-0 · 26-05-2008, 4:32 PM

Screw = bolt

AV Monkey · 26-05-2008, 4:36 PM

Ok i will drill it out to size. Should i tap wall plug in(its 1/2" wall plug supplied) and screw in bolt WITH mount so i dont need to unscrew it again? Surely if it was still plaster it would never be 80mm deep plaster or board?

Badger0-0 · 26-05-2008, 4:41 PM

Yes, it's probably ok to do that, as long as you can get a good grip to pull on the mount. Make sure it's a square pull though, as a levered pull might pull it out even if it's a decent fix.

And watch it doesn't just come out all of a sudden. I'd hate the thought of you on the floor and the mount smacking you in the face.

AV Monkey · 26-05-2008, 5:21 PM

Right. Thats it for today. 90% happy with the wall being ok for the job. Only thing is just realisted i only have up to 10mm drill DOH. Don't laught.

So will have to buy a larger one/set tomorrow.
Thanks to you both for your advice.

AV Monkey · 26-05-2008, 6:59 PM

Just as i was finishing up brother in law popped round. After further inspection of the holes he said it may be breeze block as they are very easy to drill and crumble easy espacially with the wide ended masonary bit.
The pink layer is a plaster skim and looks like there is a layer underneath whch is quite course and has small stones in it. He thinks it could be the first skim put on the breeze blocks used to level the surface ready for the second fine skim (the pink stuff) Which he reckons is often the case.
But hes not a builder hes a painter and decorater and iam sure has seen alot more walls in varying conditions than myself. So iam a bit more happy with what iam doin and hopefully initial worries unfounded.
Thanks again.

mossym · 26-05-2008, 7:02 PM

glad you're sorted

Badger0-0 · 26-05-2008, 7:28 PM

Not quite sorted yet, IMO.

Whilst I don't doubt your B-I-L, breeze blocks are normally grey. As are thermalite, which are even softer.

Whatever, depending on what fixings you have, you may need to change to different ones suitable for breeze. I've seen rawl bolts just split breeze blocks in half.
Then again, if you fix one and can't pull it out, it should be ok.

AV Monkey · 26-05-2008, 10:14 PM

The fixing i have came with the mount. There is a selection of varying size screws which the instructions ask you to use when fitting to plasterboard with the wooden batons behind. The fixings i am using are specified in the instructions for use with brick,solid concrete and concrete block.
The bolts have a hexagonal head with a shank of approx 15mm then the thread. This thread starts thinner at the shank then gets thicker in the middle then thins again at the end. They are described as lag bolts.
The wall plugs are grey. Fairly soft plastic. 60mm long and 12mm diameter. They have splits running their lenght at the start they have a parellel lenght with no splits similar lenght to shank on lag bolts. They have barbs just after this then the thick ribs. As the thick middle part of the thread on the lag bolts screws in it cuts a thread in the plastic and pushes out the wall plug.
Do these sound safe?
The dust coming out was light grey. When i rubbed it between my fingers it went white. And smelt a bit like concrete.

invu2day · 27-05-2008, 12:15 AM

Quote:

Originally Posted by andyhill

The fixing i have came with the mount. There is a selection of varying size screws which the instructions ask you to use when fitting to plasterboard with the wooden batons behind. The fixings i am using are specified in the instructions for use with brick,solid concrete and concrete block.
The bolts have a hexagonal head with a shank of approx 15mm then the thread. This thread starts thinner at the shank then gets thicker in the middle then thins again at the end. They are described as lag bolts.
The wall plugs are grey. Fairly soft plastic. 60mm long and 12mm diameter. They have splits running their lenght at the start they have a parellel lenght with no splits similar lenght to shank on lag bolts. They have barbs just after this then the thick ribs. As the thick middle part of the thread on the lag bolts screws in it cuts a thread in the plastic and pushes out the wall plug.
Do these sound safe?
The dust coming out was light grey. When i rubbed it between my fingers it went white. And smelt a bit like concrete.

Going by you're description I think you may have a thermalite block or similar product. When you drill into this make sure you don't use a masonary drill bit. This will just further crumble the block. Always use a HSS (wood/metal/plastic) drill bit on the slowest speed, size 10 is sufficient. The fixings supplied will not keep the intended grip in this material. Once you've drilled out the holes clean out all the dust and fill with a chemical resin such as :

http://www.screwfix.com/search.do;js...h_search=23386

Then insert a resin stud such as :

http://www.screwfix.com/search.do;js...h_search=97036

and allow to set.

I've just attached a 42pz85 to a Vogels swing and tilt bracket

http://www.vogels.com/pages/consumer...tion=31&id=783

to a thermalite wall and it's as solid as a brick fixing.

Hope this helps

AV Monkey · 27-05-2008, 2:17 PM

Thanks for reply,
That all sounds a bit technical for me. Guess i will just have to pay for it to be done by the tv shop install guy after all. I don't want to mess it up. I already have 6 holes in my wall don't want to do anything else or this could end up a can of worms.

invu2day · 27-05-2008, 2:35 PM

Quote:

Originally Posted by andyhill

Thanks for reply,
That all sounds a bit technical for me. Guess i will just have to pay for it to be done by the tv shop install guy after all. I don't want to mess it up. I already have 6 holes in my wall don't want to do anything else or this could end up a can of worms.

Just sounds harder than it is. If you already have the holes drilled in the right places all you need to do is clean out the dust, inject the resin straight from the tube, insert studs and wait for it to cure. A good few hours should be enough. Then hang your bracket. If you need reassurance you can pm me and i'll get in touch.