loading on rawl plugs and cavity wall fixings

[chunkolini]

Hi guys
I make and sell shelving units (www.coolshelving.com) and am frequently asked how much weight can you hang off wall fixings.
I supply rawl plugs to people with brick walls and those large cast aluminium fixings with a very coarse thread to people with cavity walls.

I am sure that years back I read that cavity walls can support a large weight as long as it is acting vertically rather than sticking out from the wall.

I have never had a problem but it would seem more professional if I could quote figures, Can anybody help?

Thanks for your help,

Chunko'

 

[Scrit]

Hi Chunko

One of the few retail market firms to supply detailed loading and pull-out information about their products is Fischer. Their products are relatively expensive, but then quality costs. Industrial fastener firms such as Spit and Hilti are also very good for information about their own products. If you take information from these firms it will only apply to their products as many of the generic products are not as good

Scrit

 

[Paul Chapman]

I have never had a problem but it would seem more professional if I could quote figures

If you are supplying these for your customers to fit, then I would be inclined to add a proviso which says something along the lines of "provided they are fitted in accordance with the manufacturers instructions". My observations suggest that Mr Average has great difficulty drilling a hole in a wall and knocking in a Rawlplug :shock:

Cheers :wink:

Paul

 

[Pecker]

Ok for 2 years I worked for Thorsman, who actually invented the plastic plug and the colour coding system that goes with them - it wasn't Rawl by the way, thats quite an interesting story by itself).

You need to be extremly careful when quoting pullout values of any fixing. The rate will depend on how good the substrate -ie the wall is, how deep you fix them, exactly what size of screw you use. How far from an edge and distance apart.

Then it depends on if they use virgin polymers to make them, or recycled fish crates and traffic cones.

Finally it depends on exactly which type of fixing you use, and what make. (heres how technical it gets..."Ductile reinforcements can supply fracture toughness to a polymer matrix by pulling out and by plastically deforming)

Fischer make very good fixings, but as stated are expensive.

Have a look at this link which gives some good values. http://www.deltaleigh.co.uk/pdf/plastic-wall-plugs.pdf

You asked about vertical loading, yes they will stand more weight vertically but in fact unless supported on the floor a vertical shelf support will actually pull out horizontally.

Cover your buttocks and dont get too specific about loadings or you may get into hot water.
There, you didn't know it was so complaex did you?

The screwfix catalogue used to give sme values, as does the fischer website
woody

 

[A_n_g_e_l_a]

Why not make up a few up shelves, fix them to various substrates, and do your own load tests? You would benefit by having a certification engineer on hand to witness and verify the results (suggest Lloyds Register). Or you could farm the tests out to an independent company. Either way you would then have verifiable documentary and, even possibly, video evidence to back up any claims you made.

It will cost you money ... but it will also give you bragging rights in your advertising.

 

[Hitch]

I quite agree with Paul, i am a member of a few forums, ( i recognise you from somewhere- UKWelder?) and it seems one of the most common problems is something as simple as drilling a hole in a wall. :roll:

Theres so many different plugs available, and so many variables. to consider.


This might be of some interest....
http://www.ultimatehandyman.co.uk/F_F_F ... IXINGS.htm
Perhaps printing out a similar version to supply with your kits may help people.

Perhaps supplying branded plugs may be the way to go, only a few pence extra, but you can give specific details on them should it be required.

 

[inventor]

Somewhat off-topic, but, if you have to hang anything from plasterboard, use this:
https://www.screwfix.com/app/sfd/cat/pr ... 1&id=95441
which is wonderful compared to anything else on earth.

Meanwhile, real values for masonry fixings? Very tough. Depends on the masonry too much!