Fixing into clay lump

[Pford75]

I'd welcome some thoughts from the forum.

I am looking to hang a TV on the wall in our kitchen and the wall is clay lump (with lime plaster on the interior). I've had problems in the past with getting a good fixing in clay lump. Given the weight of a TV - what fixings into the wall would people recommend?

 

[middi]

(Off the top of my head), I would fit a square wooden plate on the "mud" with 4 of 6" long x 10mm ( 150mm L) frame fixers screw plugs, the top two fitted at a slight downward angle. The tel. bracket then screwed onto the wood. It should work.

Middi

 

[middi]

,,,,,,you may also consider the possibility of hanging it from the ceiling if possible.

 

[Pford75]

Thanks Middi.

The ceiling is 14'6"...so I don't think that will be an option!! I'd wondered about using a 'plate'...agree that would help/ You don't think rawlbolts would be better than frame fixings?

 

[Flyfisher]

Part of our house is chalk lump and I've had problems fixing wall lights. The problem, I've found, is that the slightest movement of the fixed item will easily enlarge the hole so that normal 'rawlpluggy' fixings become loose. Expanding fittings are not a lot better - they're fine at first but, again, any movement will enlarge the hole and loosen the fixing. At least expanding fittings (e.g. rawlbolts) can be easily re-tightened, but they need to be deep fixings because otherwise the expansion pressure just pushes the wall material to the front of the wall where it can easily crumble.

In the end I removed the original plug fixings and hammered a suitably-sized piece of oak into the wall, to a depth of about 4-5 inches (after drilling a pilot hole) then drilled a pilot hole in the oak and fixed the lamp with stainless screws.

And all that is for fairly lightweight items, I'm not sure what I'd do for a heavier unit like a TV. I mentioned the above in case you're thinking of a wall-mount that allows the screen to be moved/angled because that's the sort of thing that will loosen fixings.

 

[middi]

Raw bolts will also be fine ( and probably better). The trick is in the final tightening pressure, this must not be too excessive otherwise the expanding flange of the bolts or plugs will eventually commpress the clay , if the clay is on the soft side it will spin, leading to a loose plate. the idea shuld be to use as long as possible fixings, at an easily working angle and not too tight.

Middi

 

[middi]

FF's idea is an exellent one, large "wooden raw plugs", albeit a bit messier.

Middi

 

[Pford75]

Don't some fixings come with a 'resin'? Have you tried those?

 

[middi]

If you wish to use resin " clamped" fixings it will be the best way forward. You will definetely eliminate any " initial" anchorage movement . Whatever you eventually decide to use, the strength of anchorage will be in the depth of the fixing.

Middi

 

[Moo]

We anticipated the same problem with our reclaimed radiators, so we hung them on the floor.

 

[Feltwell]

How about fixing studs into the wall with resin, then fixing the TV bracket plate to the studs? That way you can go as deep as you like and there are no expansive forces on the clay lump, and you can let it go off thoroughly before you put any weight on it.

TV brackets are a swine, especially ones on an arm - the "flat to wall" type are easier and put much less strain on the wall fixings. My kids had a medium-sized telly in their playroom for video games, that I tried to bolt to a wall that (I didn't know this at the time) had been rebuilt with an inner skin of aerated concrete blocks. I just couldn't get a decent fixing - in the end I put it on another wall, which was normal 9" brickwork.

TV brackets are a bit of a con as well. Decent ones for large TV's can cost well over £100 from retailers - but I can tell you from first hand experience of importing them that I never found one that cost more than £10 to make, including the shipping from China. The cheap and nasty ones are just that, the decent ones seem to command a huge markup. Have a look online for them, I certainly wouldn't bother with high street electrical stores.

We anticipated the same problem with our reclaimed radiators, so we hung them on the floor.

Not sure that qualifies as hanging Moo.... :wink: (Thought I'd get in before the PPUK Pedantry Police!)

 

[Moo]

Perhaps I should have said "hung them from the floor"?

 

[Feltwell]

Or even better "stood them on the floor"? :wink:

Sorry Moo, I feel cruel picking on you of all people. I shall chastise myself immediately - Naughty Feltwell, go and sit in the corner and say 100 Hail Mary's.

 

[Pford75]

Ive decided to go with 160mm resin stud fixings. The TV bracket itself has 4 main fixing points which are well spread, so I am hoping that will be ok. I'd rather not have a 'plate' behind the bracket as it will push the TV out further.

I agree on the cost of the TV brackets - but I've found that electrical retailers can be haggled with....I got them to match John Lewis price and throw in the bracket, HDMI cable and glasses in lieu of JL's 5 year warranty

 

[Feltwell]

You could go deeper than that if you wanted - using ordinary threaded rod that you cut to length yourself. Screwfix sell the resin seperately, I imagine Toolstation do to (and are probably cheaper).

 

[Penners]

We anticipated the same problem with our reclaimed radiators, so we hung them on the floor.

Not sure that qualifies as hanging Moo

No - it qualifies as wit!

 

[Feltwell]

It's been a long day. Very long.

 

[Penners]

Pford - I have to be honest and say that I'd be a bit worried about hanging a big, heavy TV on a clay lump wall, no matter what fixings were used (unless it's possible to drive bolts right through the wall to the other side, then through a large spreader plate). My concern wouldn't so much be for the time when the set is first mounted, but later on.

As FF said, "earth" materials have a nasty habit of loosening and crumbling very easily, particularly if there's any movement in the load on them. So, whatever fixings you use, I do suggest that you keep a close eye on the stability of the setup as time goes on - particularly if you will moving the TV around, perhaps angling it one way or the other from time to time.

 

[Flyfisher]

Resin will certainly hold any screw/bolt with more than enough strength to support a TV - and much more. The risk is that the resin plug itself comes out whole, even though it's still firmly fixed to bits of the clay lump.

I'd certainly give it a try but, as Penners cautioned, keep a careful eye on the solidity of the mounting bracket during the coming weeks.

Plus, make the fixing hole as deep as you can. The clay lump near the surface will easily be 'pulled' apart but further into the wall it will be held together by the compression of the surrounding clay (hopefully) and that's the stuff you need to tap into.

 

[AMc]

I'd second Feltwell - 4 lengths of threaded rod chemifixed into the wall would be the strongest thing bar building a stud frame off the floor. That's what holds the wall plate on soft brick that supports my 8mx4m double glazed glass roof.

My big TV bracket is coachbolted in several holes into a piece of marine ply fixed across multiple studs inside a dry lined wall. I had the luxury of building and finishing the wall with the mount in mind so there is also a conduit for the wiring and a high level power socket behind the TV.
The bracket itself came from the classified ads at http://www.avforums.com for £40. High street prices were well over £100 for a similar tilt/pan mounts on twin arms capable of supporting a 42" plasma. I also saw identical (looking) ones on ebay for roughly the same money but I'd check the feedback e.g. http://www.ebay.co.uk/itm/Swivel-Wall-Mount-Bracket-SONY-SAMSUNG-Plasma-TV-/200422863297?pt=UK_Home_Garden_LivingRoom_TV_Furniture&hash=item2eaa2231c1
Mine is angled and pointed in one direction permanently - thankfully there is no need to swing it around - that would give me palpitations given the weight of the TV and the potential leverage of those arms extended 3 feet into the room :shock: