Mounting on dry-lined walls

[thedoc]

Maybe a stupid question, but I'm sure you installers will have a clear answer!

I'm going to mount a 32" 18Kg LCD unit to a wall. The wall is basically breeze (not thermalite!) block with dob&dab plasterboarded (aka Dry lined)

I'm going to use 10mm diam window fixings with those huge raw plugs, I think they're 150mm long IIRC.


Question:

I drill the holes then, for the best fixing, should I knock the raw plugs all the way in to the breeze (i.e past the plasterboard surface) or should I knock them flush with the plasterboard surface to match the screw length?


I'm not a newbie on DIY but this has always confused me. I'm pretty new to dry-lined walls since a house move, and I've hung curtains, built and attached a bar, shelves etc. and never been sure quite how to achieve the best fixing into breeze, dry-lined walls.

Can anyone finally set my mind at rest and answer this silly question!?

(P.S Also, can one do the same with thermalite dry-lined walls - or would the block give way when the screw compresses the raw plug??)

Ian

[.borg]

Ideally you should drill through the dabs. This gives the strongest fixings. If you have drilled through the pboard and there is no glue (dab) under the hole, you should fill the gap between the wall and pboard with some gripfill (the really sticky stuff the trade use -avaialbe from travis perkins and now B&Q I think?) and let this set firmly, approx 24 hours.

You can then proceed to plug and screw in the normal fashion i.e knock the plug into the wall to just below the surface of the wall finish.

Hope this helps.

Regards

Michael

in really light blocks it's not ideal to use compressive fixings but better to use a resin fixing - just like gluing the bolt into the wall. Fischer do commercial fixings and are available from trade merchants rather than your usual wickes or b&q....

try this link for more info on the fischer injection mortar FIS V:

http://www.fischer.co.uk/english/befestigung/befestigung_frame.html

then navigate to DIY:PRODUCTS:BONDED ANCHORS:FIS V Injection anchor.

[thedoc]

Thanks very much...

Great stuff Gripfill, happen to have a few tubes in my garage at the moment.

Hadn't dawned on me to do it that way! :thumbsup:

How do you fill the cavity if mounting something a bit smaller like say a light shelf that is using No.8 screws for example? Is it better to drill out, gripfill then place the raw plug and wait for it all to dry for 24 hours before then screwing in?

I'd kinda figured that Thermalite probably won't withstand compressive loading, judging by how many cracks I've got in my Thermalite garage. The blocks have a lower tensile strength than the mortar they've been put in with! Thanks for the tip on resin bonding for that one, I'd not realised that stuff existed!

While on the subject of modern walling techniques, have you seen that ready made partition wall stuff they use nowadays? It seems to be two pieces of plasterboard bonded and sandwiching a cardboard inner. How on earth can you mount anything meaty on that stuff if you can't get access to slip a conventional stud down between the two pieces of plasterboard???

I reckon all modern built houses should come with a manual describing how safely to attach stuff to the different types of walls. It was far easier before we had dry-linings, and when every partition was a stud wall setup !

Ian

[flexiondotorg]

I am just adding this information here in case anyone else searches for thermalite in the future looking for guidence.

I mounted my Panasonic TH-42PHD8 (31.5 Kg) on a wall which is ultimately thermalite using the slimline falt wall mount currently available from AV-Sales. Here is the URL to the slim line wall mount...

http://www.av-sales.co.uk/proddetail.php?prod=OPB05-NT&cat=190&nav=26

Every other dry wall in my house is a stud partition, but when I used a stud detector to find the wooden studs in my front room it was plainly apparent that this wall was dot and dab.

I am not a regular DIY'er, so I was absolutely shitting myself at the prospect of hanging my own plasma but in the end it was not that big a deal. Here is what I found after drilling a pilot hole.

Thermalite -> Air gap 1.5cm -> Plasterboard 1.0cm -> Wall mount 3mm

Apparentely thermalite blocks are 10cm deep. After advice from my father-in-law I bought six Sleeve Anchors (10 x 100mm M8) from Jewsons, but here is the link to Screwfix so you can see what they look like.

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=51713&id=19292

Do not bother looking in B&Q, Homebase, Focus Do It All or Wickes for Sleeve Anchors. They either don't stock them at all, or in the case of B&Q, they don't stock the larger sized sleeve anchors. Go to Jewsons or order online from Screwfix.

Avoid using Throught Bolts and Anchor Bolts in thermalite, they have a more aggressive expansion mechanism and are really designed for use with hard masony and concrete blocks, therefore they are more likely to crack thermalite when tightened. Sleeve anchors are designed for block work and are less likely to crack the thermalite so long as they are sunk deep enough and not over tightened.

As stated by the thermalite website, I drilled the holes with a drill bit designed for drilling into metal. Each hole was drilled 10.5cm deep so the sleeve anchor was flush with the plasterboard. This means that 7.0cm of the sleeve anchor is in the thermalite block. Drill slowly and carefully so that when you come to insert the sleeve anchor it is a snug fit.

Tip : After drilling the hole, insert a drinking straw and blow out the dust, this will ensure your bolt can be inserted to the full depth of the hole you drilled.

Once all six bolts were sunk in place I slipped the wall mount back plate over them and finger tightened each nut to hold the wall mount in place. Then with a spanner I tightened each bolt enough to feel that it had grabbed hold, then I gave each nut a full turn past its grab point.

When I hung the plasma I was careful to listen for any cracking or grating noise as the wall mount took its weight. If I had heard cracking or grating I wouldn't have continued with mounting the screen, but as I didn't hear anything dubious I countinued.

I was hoping that one or two of my bolts would go through the cement dabs, but in order to attach the wall mount in the desired location this was not possible. Going through the cement dabs would have added some extra strength, so if you have that option exploit it. That said, the fittings I put in place do seem very secure.

Like one of the earlier posters, my garage is largely constructed with thermalite so I did a test in there before I tried the plasma wall mount. I hung a 10 Kg Hoover from a single sleeve anchor which was left 3.0cm proud of the block work so that it better simulated my front room wall. It was clear to me that it was a very strong fixing. If you have the luxury of testing, then I strongly suggest you do it so you can get a feel for the drilling technique, drilling depth and a feel of the bolt grabbing as the nut is tightened.

Finally, I don't want to give the impression that I knew what I was doing or that I am accomplished DIY'er. I am not. This job was well outside my comfort zone and it was only after lenghty discussions with my father-in-law (who is a very capable and accomplished DIY'er) that I came around to the idea of undertaking this job myself. If you are not a regularly DIY'er, but feel confident you can drill a hole in a staight line, then you can do this.

I hope someone else finds this post useful in the future.

[thedoc]

Great post, thanks. I understand you can also inject resin bond down some of these sleeve anchors (see .borg's link to the Fischer site) and then let it set to ensure a strong bond between sleeve and block also.

Anyone got advice for people stuck with those cardboard/plasterboard sandwich modern partition walls then?

[flexiondotorg]

My father-in-laws preferred method was to use resin to 'glue' regular M8 bolts into the wall, but I didn't want to do that because once the bolts are bonded in place then they are permenant. Using the sleeve anchors was second choice for him, but preferable for me as it was more straight forward to fix them.

I shant comment on the question about the plasterboard partition walls as I have no experience that can help you :-(

[bix]

Just completed my install on dot and dab wall, have a look....

http://bix.cc/tvinstall.html

[flexiondotorg]

bix, very nice guide and a nice setup too. Looks great.

"and it's even better knowing that I did it myself."

I couldn't agree more :-)

[sherbert79]

I work for a major house builder in the UK as a material Buyer and i am a qualified joiner, i mounted my 37" LCD on to a brick plastered wall and it turned out ok.Basically if its dot and dab then as before try and hit the dabs for a solid fixing if not use the liquid nail or similar as stated above.If your walls are metal stud or paramount sheeting (two sheets with cardboard inside) then i would recommend cutting the sheeting off and putting a bit more framing in to create more fixings as this paramount is only glued together with the cheapest of resin and would come apart under the slightest of pressure.

scot

[idb]

Sherbert I am mounting a 16kg LCD above the fire place. I appear to have Breeze Block, do you think this will be case? When I pat on the wall some of it sounds hollow and some solid, would you use raw bolts.

Thanks for the help

Ian

[sherbert79]

IDB

Sounds like you have aggregate block (breeze block) with dot and dab platsterboard on it, you should try and locate your fixings through these dabs as these give the best fixing, if you cant do that then read the posts above regarding using liquid nail or similar, personally i would use something a bit more heavy duty than just a rawlplug ie a sleeve and anchor you can get these from any DIY store with M10 bolts or whatever your wallmount will accept.

any probs let me know

scot

[idb]

Thanks for the advice Sherbert I will do it this weekend and let you know, and yes I agree I should use raw botls etc

Thanks Again

IDB

[phil2415]

I have a similar scenario to lots of people here - I'm about to mount a 16kg TV to what I think is a dot and dab wall. Will 'No More Nails' work the same as Gripfill or is it not as good? I'm planning to use it to fill the gap between the plasterboard and the breeze block which I hope is underneath! Any advice gratefully received.

[~Chris Peaduck~]

bix, very nice guide and a nice setup too. Looks great.

"and it's even better knowing that I did it myself."

I couldn't agree more :-)

Well done on a good finished product. I read through your installation thinking wha.. huh.. why.. just get a sparky to do it ! but when I saw the finished job I thought woah yeah that looks sweet as a nut ! pat on the back for you my man.. you must be chuffed with yourself. PS I'm a plumber (a friendly one at that!) and that guy overcharged you :mad: . But on the upside you saved a good couple of hundred on the custom install job so you're still way ahead :smashin:.

[sherbert79]

Instead of using rawbolts, gripfill or liquid nails you could always cut out the plasterboard and put some timber strapping on to the wall, obviously it would have to be the same thickness as your dabs behind the plasterboard and it would give a pretty good fixing!! then just screw the plasterboard back on and ames tape over the joint, make sure you mark out the centres of your strapping so you can locate them when covered over.

sherbert

[disco1]

Instead of using rawbolts, gripfill or liquid nails you could always cut out the plasterboard and put some timber strapping on to the wall, obviously it would have to be the same thickness as your dabs behind the plasterboard and it would give a pretty good fixing!! then just screw the plasterboard back on and ames tape over the joint, make sure you mark out the centres of your strapping so you can locate them when covered over.

sherbert

I am planning my LCD instal for the w/end and was thinking more or less the same. Cut out the Vesa base size out of p/board, insert wood with gripfill then bang the mount straight on to the timber with bolts going through to the brick/block behind.

[sherbert79]

just make sure you have fixed the timber on tothe wall securly, you will also need to choose the length of your bolts carefully as if they are too long the will go straight through the timber and hit the block/brick.Let me know how you get on.

sherbert

[disco1]

just make sure you have fixed the timber on tothe wall securly, you will also need to choose the length of your bolts carefully as if they are too long the will go straight through the timber and hit the block/brick.Let me know how you get on.

sherbert

I was planning on using some 5"-6" bolts/screws so they go a good 3"+ in to the block behind. The wood won't be taking any stress and will be used just as a spacer to make the mount flush with the wall. The bolt holes will also be pumped with gripfill then the plugs inserted and left for a few hours before mounting.

[kev777]

I had dot and dab plasterboard on thermalite and fixed my pioneer pdp 506 using resin and 9 M10 bolts.. and still there 3 months later!

do a search for thermolite and you'll see my post

[Rich1701]

Brilliant guide. Just about to embark on putting plasma on wall. Is there a calculation involved as to how far from the floor/ceiling to place bracket in relation to sitting distance or is it just whatever is comfortable? I was going to cut out a piece of cardboard (43") to get comfort factor.

[flexiondotorg]

I have seen recommendations of 10 - 18 degrees mentioned, but my viewing angle is more than that and still very comfortable. This is by design as we have a two seater reclining sofa in front of the screen and three reclining chairs either side, they are designed to keep you neck and head supported for big screen viewing. So, I would advocate doing your own comfort tests rather than following prescribed measurements. I used a cardboard cut out too :-)

My screen is mounted much higher (over an ornamental fire place) than is considered "normal" yet it is far more relaxing to watch than our old 28" CRT on it's stand.

[ManGina]

Loads of usefull stuff here - thanks to everyone I now know about dot and dab. If I'm mounting a 40kg plasma (probably a Pio) above a gas fire (it's not too hot but I have to avoid the flue) is it best to cut out some plaster to id wether its block or thermalite behind ( and how do I tell the difference please). Do I fill the hole with grip fill and go for the bolts then plaster over the hole or do I not cut a hole just drill normally through plaster/gap/and into whats behind and use really long plugs like someone mentioned here?
My main problem will be avoiding the flue because I will have to avoid using the central line of the plasma mount. I haven't got either plasma or mount yet so can someone tell me what distance there is between the outer bolts and if the mount has holes in the center line also.(Pio or universal mount)I hope you can picture what I'm trying to say.
Many thanks again you guys-this site rocks:thumbsup:

[blicky_1]

I used 16mm rawbolts with M10 threads x5 to mount my 42PD6600 on a plasterboard dot/dab wall with thermolite behind, bolts were pushed into thermolite until they were flush with the face of it. After a couple of weeks I had had enough of the 6600 and swapped it for the 42PD7200, as it was mounted above a fireplace the bracket (Ebay) was too high for the new screen so it was moved down 5" with the same rawbolts!!

At first I was checking the bracket everyday but it has been up 3 weeks with no sign of comming off!! :)

[fuzed]

wish me luck, mines going up hopefully this weekend... although the bracket supplied is a vogels, and its only got a tiny bracket to go on the wall with 3 holes for bolts - kinda scares me looking at it!!!! but seeing as its a well designed bracket etc etc - it should be fine... well I hope so!!!!!

[Doer1]

Just a quick tip.... when cutting plasterboard I use a Dremmel ceramic title cutting bit (Looks this a drill bit got is from B&Q) I use it with a normal drill. cuts very neat and any shape you want.. :thumbsup:

[pokey-pola]

Hi,

Sorry to resurrect this thread but would someone be able to clarify how you would use the gripfill between the plasterboard and block?

Do you drill through the plaster -> gripfill the space between -> leave to set 24 hours -> drill through gripfill and block -> push sleeve into the hole?

or

Do you drill through plaster and block -> gripfill the space -> push the sleeve anchor through the gripfill into the hole?

Thanks.

[JonnyFive]

Just another tip people. When mounting on a dry lined wall there will obviously be a gap between the hole in the block and the hole in the plasterboard. In my experience this hole needs to be spaced out or it pulls the fixing towards the bracket instead of the other way round. Most brackets come with spacers whether they are plastic or metal. I just found if you slot these into the holes in the plasterboard after the fixing you chose things go a little better. ( so basicly drill your holes straight through the plasterboard and block, insert your plug or anchor fitting, then the spacer, put your bracket up and tighten all your bolts.) Its probably also worth mentionin that over tightening is not advised as thinner more crappy plasterboard can actually start to pull through. Its alot of force on the plasterboard and the bracket itself is a large washer when you think about it, but every washer has a point where it will pull through the material its on top of. Good luck people. If anyone needs any advice on this pm me. I seem to have every which wall contruction in my house. Plasterboard, brick, thermalite, dry lined, cardboard. lol.

[Stephen Creaser]

Hi, I am mounting a px600 th42 and im using 8mm resin fixed studs into block. What I need to know is how big should i drill the hole to allow enough resin to get round the stud when i insert it

Thanks

[DJBlade]

Can you post some pics of this tool - Dremel Tile Cutting - thanks....

[RABG]

Hi All

look here 42" Plasma mounted on p/board no fixings in studs

Fischer UX 10 universal plugs with 6mm dia screw need any

advice PM me I sell fixings for a living.

http://i87.photobucket.com/albums/k123/RABG/7edfa467.jpg

thread

http://www.avforums.com/forums/showthread.php?t=375613


Rab.

[dieselpower]

I just took delivery of my new Persimmon home today :clap: I ran the stud finder across the livingroom wall and it struggled to pick anything up. Anything it did pick up it couldn't find in the same place twice. I'm pretty certain the unit works as it's worked on other walls.

Anyone any idea what the wall structure might be? It is an external wall.

Any advice greatly appreciated :)

Rab, you'll get a PM via TRS for some fixings mate! :smashin:

Cheers,

Andy

[T0rNaDo]

hard to say really.

it could be dot and dab ?

[dieselpower]

I took one of the phone socket boxes out the wall and I've got plasterboard, then a gap of about 40mm then the timber frame then brick. I can't find any studs between the timber frame and the plasterboard though :(

Any ideas? :lease:

[miltsharman]

I took one of the phone socket boxes out the wall and I've got plasterboard, then a gap of about 40mm then the timber frame then brick. I can't find any studs between the timber frame and the plasterboard though :(

Any ideas? :lease:

I'm in a similar situation: plaster board,gap. plastic sheet, insulation, plastic sheet, wood. cant see beyond the wood so dont know if i have more brick or b block before the outer bricks
(Can you have an external wall thats only one layer of bricks?)

any ideas? :lease:

[dieselpower]

Well the stud finder was faulty, as was it's replacement so I've now got a completely different one.

I'm still not sure what's the best way to secure the mount. Umbrella fixings just don't inspire any confidence. They are holding up a 19" LCD fine but it weighs next to nothing. I know someone who has a huge plasma held purely to the plasterboard but I'd rather have something more secure.

I am luckily that there is a stud smack in the middle of the wall, so vertically it will be secured to wood, but the edges I'm still not sure about.

Anyone with any good ideas??

[miltsharman]

I'm in a similar situation: plaster board,gap. plastic sheet, insulation, plastic sheet, wood. cant see beyond the wood so dont know if i have more brick or b block before the outer bricks
(Can you have an external wall thats only one layer of bricks?)

any ideas? :lease:

bump
any ideas as i'm hoping to start work in 2 weekends time
any advice appriciated:lease:

[mr-gobby]

miltsharman - You can have a one brick external wall. It could be that you have a timber framed house. This is where the construction is inner walls are timber and erected first then the outer brick skin is constructed around it. If your on a recent development go and enquire at the show home, look at the next phase being built or alternatively contact the developer directly.