Which Floor Fixings Should I Use?

RAWL PLUG BOLTS  Chemical Anchors

There are many different floor fixings or anchors available to bolt your barriers to the floor but they generally fall into two main categories:-

Mechanical Anchors

Mechanical anchors are generally cheaper to purchase and easier and quicker to install.  This type of anchor should only be used with solid, strong concrete.  If the concrete is weak and crumbly the anchor will not tighten properly and has the potential to become dislodged under stress.  Also, because all the weight and stress is concentrated at the tip of the anchor it has been known to cause cracks in weaker concrete.

Generally though, in a good substrate, they do the job effectively and well.

There are a number of mechanical floor anchors but on this website Advantage Safety Barriers offer a choice of the two main options.

 Through Bolt Anchors

 Through bolt anchors are designed for use in solid strong concrete or dense natural stone with a strength greater than 20N/mm2.  They are probably the most widely used fixing bolt in today’s market.

The anchor bolt is inserted into a hole drilled in the base material.  The nut is placed on the top of the threaded bolt above the baseplate and as it is turned it pulls the stud up through the expander sleeve, forcing it up against the inside wall of the base material.

The through bolt requires a hole in concrete the same diameter as the bolt.  This allows the hole to be drilled through the base plates and avoiding lengthy marking out procedures. . However, once in the ground the bolt cannot be easily removed.  Should the barrier require repositioning or temporary removal, when the top fixing nut is removed, the bolt will remain in the ground with the top of the bolt protruding above ground level.  This will create a tripping hazard if it is not ground back level with the floor.

Overall, through bolts are a versatile, cost-effective anchor combining ease of installation with good load carrying capabilities.

 Rawl Plug Floor Anchors

Rawl plug bolts comprise a long threaded screw with a hex bolt head and plastic rawl plug sleeve.  They will provide a secure anchor performing as well as the through bolt equivalent.

The fixing process takes longer than with through bolts as the base plate and fixings positions will need to marked out on the floor and the barriers set to one side before drilling in order that the rawl plug can be hammered flush into the concrete base.

The principal benefit of using a rawl plug bolt is that the bolts themselves can be removed easily if barriers need to be re-positioned or temporarily removed.  As described above, with a through bolt, when the top fixing nut is removed, the bolt will remain in the ground with the top of the bolt proud of the floor.

Chemical Anchors

Chemical anchors are steel studs, bolts and anchorages which are bonded into a substrate, usually masonry and concrete, using a resin-based adhesive system.  They are ideally suited for high load applications and are required if the Advantage Safety Barrier ‘Flex’ pads are used with our railing systems and tubular protection guards.

In virtually all cases, the resulting bond is stronger than the base material itself.  No load stress is imparted to the base material as is the case with mechanical anchors.  They are recommended for close to edge fixing and for use in concrete of unknown quality or low compressive strength.

They also provide the benefit of waterproofing the drilled anchor hole.  A mechanical fastener has a slight gap between the fastener and the base material.  In a chemical floor fixing, the resin fills the void between the bolt and base material, making the connection water-tight.  This makes them a preferred choice for external floor fixings as well as in any other areas where fluid leakage is a factor.

On the down side, chemical anchors are more difficult to install and the process is more expensive.  In order to install a chemical anchor, you must first drill and clean the hole thoroughly as any leftover dust or particles will greatly reduce the effectiveness of the adhesive.  The installation process takes longer and you can only apply loads to chemical fasteners after the chemical has set.  Loads can be applied to mechanical fasteners immediately after installation.