shear force or pull force, kgs or newtons?

[Tubsy]

hi guys, can anyone clear up a technical question whats the difference when measuring 'shear force' and 'pull force'? ie; that surface has a shear strength of 20kg's per meter' i ask because i recently got involved in a discussion?.........no argument?.....................no a 'fight to the death' with a builder about some very heavy marble slabs and wall surface preparation... i quoted advice from tta about background etc..and he come back with your talking about pull force and i'm talking about shear force. so i checked my facts with the manufacturers of the tanking products we were going to use and the mentioned that their product has a pull force of 0.5 newtons???? so how doe's that relate to kilograms per sq meter? completely confused now sorry for going on but can someone clear the mist for me

[Colour Republic]

shear force is parallel - pull force is perpendicular

Edit: hanging a picture on a wall would create shear force, hanging a punch bag from the ceiling would create pull force

[oldgit]

i dont really understand fully what your saying but im guessing your saying what is being applied to the wall is really strong and will hold up the said tile.
but surely even if it could hold any amount of weight it would make no difference at as it depends on what the tanking product was applied to that is really how strong it is ie:if it was plaster it would be x kgs or wedi would be y kgs.
so whatever the original substrate is that is where your guided as to what weight can go on it.
i think!!!!!!!!!!

[Tubsy]

i just re-read my post and it is confusing how i have put it.

let me try again, the builder had prepared a wall by lining it with ply wood. 15mm x 50mm battens horizontally and 18mm structural ply over fixed at 600mm centers.
i was horrified to think he would be sticking the marble sheets to this ply.
the customer asked for an opinion on the wall preparation and i remarked that it would not be suitable for a natural stone of the size they were installing or any where near carrying the weight (60+kgs per meter sq)
i recommended they remove ply and use wedi board dabbed and dowelled to the brick work (this info was checked with tta and on here)i also recommended using mechanical fixings on the marble, pins and wire resin-adhesive etc... red faced builder then had a go at me apparently i didn't have a valid opinion and he's been a builder for years!!! i tried to ask how often in those years he'd stuck up 1800 x 1200 marble sheets and he blanked me! sorry rambling again..
my question was when i asked the manufacturers of the products we use they start quoting pull force in newtons for products that are applied vertically on a surface others quote shear force in kgs for the same application, common sense dictates that if it take 'x' amount of force to separate two layers from each other the strength is in how those two surfaces are attached, i.e. ply wood relies on the glue to the next bit of ply which relies on the next etc.. i get that but when trying to talk to several different manufacturers they all use different calculations........sod it any body got a phone number for issac newton!

[Tubsy]

i'm going for a lie down

[Colour Republic]

what products are quoting shear force and which ones are quoting pull force? and then i might be able to tell you why

tell the builder you'll install onto his ply if he guarantees the work

[inspiredandy]

I would be careful with this one Tubs. Say you do the job based on the builder accepting liability, if things go wrong and it went to court, you could still be held liable because you went on and did the job knowing full well there could be problems. A court would see this as negligence on your part. That is the harsh reality i'm afraid.

[Colour Republic]

I was only joking mate

[Sir Ramic]

i just re-read my post and it is confusing how i have put it.

let me try again, the builder had prepared a wall by lining it with ply wood. 15mm x 50mm battens horizontally and 18mm structural ply over fixed at 600mm centers.
i was horrified to think he would be sticking the marble sheets to this ply.
the customer asked for an opinion on the wall preparation and i remarked that it would not be suitable for a natural stone of the size they were installing or any where near carrying the weight (60+kgs per meter sq)
i recommended they remove ply and use wedi board dabbed and dowelled to the brick work (this info was checked with tta and on here)i also recommended using mechanical fixings on the marble, pins and wire resin-adhesive etc... red faced builder then had a go at me apparently i didn't have a valid opinion and he's been a builder for years!!! i tried to ask how often in those years he'd stuck up 1800 x 1200 marble sheets and he blanked me! sorry rambling again..
my question was when i asked the manufacturers of the products we use they start quoting pull force in newtons for products that are applied vertically on a surface others quote shear force in kgs for the same application, common sense dictates that if it take 'x' amount of force to separate two layers from each other the strength is in how those two surfaces are attached, i.e. ply wood relies on the glue to the next bit of ply which relies on the next etc.. i get that but when trying to talk to several different manufacturers they all use different calculations........sod it any body got a phone number for issac newton!

You dont need his number, any adhesive manufacturers number will do

[grumpygrouter]

Maybe this will explain it......not!

Newton - Wikipedia, the free encyclopedia

[Tubsy]

thanks grumpy, it will take an hour or so to deciepher the wikipedia definition but the table on there looks useful,
i have since spoke to the customer again and she is now getting a stone-mason in to do the marble (i'm relieved to hear) i will post some pics of the job as soon as i've worked out how if any one wants to see.
Ta 2 All

TUBSY...

[turnip]

quick anecdote....i have seen a stone mason install similar sized marble(20mmthick) in a wetroom to plasterboard, (the builder hadnt managed to get the board plumb) with blobs of silicone and resin of varying depths to acheive plumb! there were voids of 25mm in places. alot of shoulder shrugging from mason and builder, customer asks what happens if the plasterboard doesnt hold the marble......mason does an impression of holding the side walls from collapsing (like superman or something).....not found funny by any party present....

[beanz]

quick anecdote....i have seen a stone mason install similar sized marble(20mmthick) in a wetroom to plasterboard, (the builder hadnt managed to get the board plumb) with blobs of silicone and resin of varying depths to acheive plumb! there were voids of 25mm in places. alot of shoulder shrugging from mason and builder, customer asks what happens if the plasterboard doesnt hold the marble......mason does an impression of holding the side walls from collapsing (like superman or something).....not found funny by any party present....

Now that's worrying!

[Ajax123]

If I remember my Physics 1Kg creates a force of approx 10Newtons (i.e. mass x gravity)