Dr.Robotnik":v2rxsuhy said:
I bought this the other day;
http://www.homebase.co.uk/webapp/wcs/st ... xt%3EHOOKS
I asked what fasteners to use and was told the red rawl plug and 6mm diameter screw set where the screw is 30ish mm long. I said I'd rather get bigger and went for the brown rawl plug, 7mm diameter screws.
So I mount it all up the other day (four screws), it's rated for two bikes, I went to put the second bike on and it's ripped off the wall.
Now one I have a wall to fix now, two is this thing not fit for purpose? Thinking back 4 screws 30mm into a wall is not much is it?
I read the packet just now and it says I should use Number 13 round head screws, what are they?
Can I ask for some recompense from Sainsbury's Homebase for trashing my wall?
Cheers for any advice.
Round head simply means the head design, a round head is usual to be used when there is no countersunk depression in the thing you are fixing and in appearance side on the head is semi circle in shape, but I don't believe that is the issue here.
A number 13 screw is somewhere between 5mm and 6.5mm thick on the unthreaded portion of the screw, again I don't think that is the issue either.
What I do think is the issue, is the length of screw you used, perhaps not long enough and given old plaster and whatever is on top of that, hardly a good anchorage for the screws. Me, I would have thought going into a chimney breast which is brick with
x thickness of plaster and other crap on the surface I would have used at least a 100mm screw to put the screw tip somewhere near the middle of the brick where the brick is at it's most densest and provides a lot of very firm material for the plug forced out by the screw to grip onto.
Even one long screw of 6.5 to 7mm thick correctly fitted should easily hold two bikes plus wall fixing, as the loading on the screw is not inline with the screw, ( the worst case scenario) but at ninety degrees to it, where a
quality screw is resisting a shear force mostly, but also some extract force which results in the screw trying to bend in the hole so it can get out easier. A suitable packing in the form of a plug resists that bending but also by it's nature of being compressable, the upward force makes it grip into the drilled hole. So sorry,30mm is just not long enough and with that given old plaster which is usually thicker than modern, possibly powdery given it's age, you no way had a firm anchor.
Now, as I am kind of belt and braces when it comes to repairing or constructing things, personally I would have used a hammer in fixing like these ;
http://www.focusdiy.co.uk/HammerInFixing8X100mm716225?category=wallplugs_anchors
But that is just me, drill a hole and bash the thing in, job done, but the problem with those, is they are not very easy to remove, so the fixing becomes kind of permanent, especially so if I am in a
this is not going to come out mode, I coat the thing in glue before bashing it in.
But standard plug and screw is perfectly ok, but you will need a long drill bit, a rotary hammer usually has such lengths and far longer and will go through pretty much anything bar steel.
So, a small job has become a large job, it always does that is what DIY means,
Destroy it yourself
So the problem is length of screw, either that or you have some seriously heavy bikes, but most likely the former.
BTW, Homebase is not exactly the best for DIY, in fact when I was in the industry, we reckoned Homebase existed so a man could feel like a man, getting manly things whilst the maud shops for plants but have to submit to a better man to sort out the problems caused by the destroy it yourself crowd. I was an ex tool hire fitter, I repaired the machines the DIY lot wrecked on a regular basis, I used to hate working saturday morning, as it was when the DIY lot came out and started looking to hire manly tools to play with.
