It has become clear from the Limestone setts slip hazard problem thread that there's no easy to read industry standard for explaining the potential hazard which various surface materials might exhibit in wet or damp conditions.
I think it should be relatively easy for importers/agents/suppliers to visibly brand their paving materials in such a way that a slip rating safety mark is easily recognisable.
I have devised this simple yet effective traffic light design. It would be relatively simple to implement and roll out and it should be relatively simple to get this scheme under the noses of the big manufacturers and suppliers.
The ratings should be easy to understand, instantly recognisable: no looking in the small print on websites or brochures.
The number in the middle (in this case 36) is the safe measurement. Below this a paving surface is potentially slippery when wet. Above 36 and the paving becomes more grippy as the number rises.
Green for safe
I propose using green for safe with plus sign and rising number to indicate a paving surface's suitability during wet or damp conditions. Obviously paving materials which are branded green would be suitable for all paving applications and laid in conjunction with a supplier's recommended laying specifications:
Orange for caution - refer supplier's installation specification
The orange symbol with a minus sign and number to the left and a plus sign to the right indicates that a paving material may become slippery under certain conditions: i.e. in damp conditions in low light or under the shade of a tree, for example.
Red for extreme caution - only use where recommended by supplier and to a strict laying specification.
The red markings and negative numbers indicate that a paving material is known to become hazardous in damp or wet conditions but may be used in certain applicatiosn such as edging or on level surfaces only, for example.
Views: 49
Replies
Good proposal, I wonder whether any supplier would actually be prepared to own up to offering an orange- or red-rated paving stone??
If this information was prominent at the time of specification, then presumably a designer who specified an 'orange' or 'red' stone which later turned out to be slippery, and who didn't warn their client and obtain their approval, could be held liable if the client had a problem with the slipperiness, or even - heaven forbid - suffered an injury as a consequence? I could see the paving market contracting dramatically...
www.chameleongardens.co.uk
Hi Rose
Working on the basis that all different materials should have a slip test rating anyway it shouldn't mean that suppliers are doing anything they shouldn't already be doing. The symbols here will merely make it apparent to the specifier how the paving surface should perform in wet conditions.
If there are materials currently on the market which don't have a good slip test rating now then it's arguable whether they should be being sold for paving applications.
Rose Lennard said:
Quite agree! Just wonder whether some suppliers would be prepared to own up to promoting stone which really isn't fit for purpose - liability issues etc...
Phil Voice said:
hi folks,
Ive been reading this topic, it is a good proposal, as for suppliers - all they have to do is stock the stone at a level each type is selling at. I would think a majority of purchasers would buy a stone that had a good level of safety as far as use for paths, social areas or driveways, and then possibly lower grade of stone for more decorative purpose.
It would be interesting to see the measurement that the different types of materials came in at, like your average 2x2 or 3x2. these slabs are sometimes made with the little dimples. I guess its watch this space on LJN :-)
Rose, I don't think the problem is with the paving industry as such, just that the number of materials available has grown exponentially over the years. That, as always, leads to clients wanting something they've seen, or designers wanting something different to the old standard products, and no regard being paid to the suitability of the product for the UK.
When I were a lad, all you could buy were broken slabs from the council to use as crazy paving. Now, we have materials from all over the world, with a baffling amount of finishes. Some products are fine to use indoors, others are able to cope with the UK conditions. Selling a "red-rated" stone won't stop, it would just be clear it was an internal product. Even the products not suitable for foot traffic can have uses in garden designs, as edging for example.
Hi Paul
Stone suppliers do already make a distinction between stone for interior and exterior use, mainly based on frost resistance. I would be surprised if there weren't a large number of stone lines being offered which are not fit for purpose in terms of skid resistance in normal weather conditions out of doors. Even use as edgings can be hazardous, for example if used around a pond. If a slab is large enough to be walked on, and is offered as suitable for external paving, it should not be dangerously slippery when wet (providing it has been properly maintained, ie regularly cleaned). To my mind, it's like selling a car with no brakes...'oh, you wanted to stop?? I thought you just wanted to go forwards. You should have said!'
I know there are degrees of slipperiness, and we all know that decks, for example, unless kept scrupulously clean, can get slippery when wet, but we still design decks into gardens and public spaces (though we may take precautionary measures like incorporating anti slip step nosings, or look at synthetic alternatives in locations where slipperiness would be a serious problem). I think it will be a very good move if some sort of easily understood traffic light rating is introduced so that the slipperiness of any stone is understood at the point of specification, so that our design choices are fully informed, and both designers/specifiers and clients know what they are getting.
Paul McNulty said:
BTW My simple traffic light concept is based on the belief that if a supplier has nothing to hide then they also have nothing to fear.
Under this simple scheme, if a product comes in with a slip rating of 30 then one has to question if it should be sold as an exterior product?
Also...if a product is sold for interior use only because it has been found to be unsafe in an exterior application then quite clearly a red slip rating is only saying that this product should not be used outside.
How many of us have seen interior domestic products (i.e. thin natural stone tiles) used as a patio surface before?
In this example the traffic light code is simplified to just a coloured ring with the slip test number encircled.
Green circle is obviously safe in all applications based on slip test data
Orange indicates that a material should only be specified in certain circumstances and applied with care. For example low light or under trees.
Red indicates exterior edging or interior use only.
I would have no problem working with a system as Phil devised, but I don't think it would ever fully be implemented across the board. I cant see a situation when the red light will ever be used.
Suppliers who are selling exterior stone which falls under the red light category are never going to put a red light next to one of their products, its just not going to happen. Experienced suppliers will not be selling exterior products which would fall under the red light category, so again the red light will not be used.
"Also...if a product is sold for interior use only because it has been found to be unsafe in an exterior application then quite clearly a red slip rating is only saying that this product should not be used outside"
Products sold for interior use are going to be displayed inside showrooms or marketed as interior stone tiles, so its not realistic to expect suppliers to put red lights next too products which are already clearly identified as being for interior use. Also products are not selected for interior use on the basis that they have first been found unsuitable for exterior use. Stone starts off as a big rock and different surface finished are applied by the supplier depending on the required application. For example granite for interior use will be first sawn to create the tile size (eg 600x600x15mm) the surface will then be polished to improve the aesthetics. Granite for exterior use will be sawn to create the paving size (eg 600x600x25mm), the surface will then be flamed or fine bush hammered as these two finishes are the most common ones used to provide a textured but also aesthetically pleasing surface
"I would have no problem working with a system as Phil devised, but I don't think it would ever fully be implemented across the board. I cant see a situation when the red light will ever be used."
I do hope that's the case Steve. A red circle indicates it's not fit for purpose.
What I am encouraging here is the paving supplier to publish an independent slip test result. Anything lower than 36 indicates a material is not ideal for exterior use.
-
1
-
2
of 2 Next