Technical help

Frequently asked questions

Here you’ll find answers to the most common questions we are asked about our products.  If you don’t find the answer you need here, call our technical engineers for advice on +44 1752 895288.

Armoured joints which also act as leave-in-place formwork (such as our AlphaJoint and BetaJoint) are used to create a boundary in which to contain a day’s concrete pour.  As the concrete sets and contracts, the two sides of the joint (held together with frangible rivet connectors) are gradually pulled apart horizontally.  Dowels fixed through the centre stop the slabs moving vertically and allow for load transfer between the two sections of the floor.  Once the floor has contracted, the gap between the two sides can simply be filled with a suitable joint sealant.

Armoured joints have several benefits:

  • they act as permanent formwork and as day joints, helping to speed up the process of the concrete pour, and ensuring a reliable result;
  • they control the movement of the concrete as it contracts, preventing random cracks from occurring in the slab;
  • they protect contraction and expansion joint arrises from damage once the building is in use, preventing costly repairs to both the floor and materials handling vehicles;
  • they facilitate load transfer between the two sides of the slab, so the slab remains consistent and even during use

Permanent formwork isn’t necessarily an armoured joint.  Some permanent formwork will provide a day joint for the concrete pour, but won’t provide arris protection.  In our Product section we’ve separated out our armoured joints from our formwork, so it’s clear which benefits each product will give.

Typically you can use formwork for areas which won’t receive much traffic, such as the perimeter edge of the slab.  But where there’s likely to be more traffic, it’s important to choose a product which will provide permanent formwork, joint arris protection, and load transfer. 

This will depend on several things, such as the type of building, how it will be used, and the type of vehicles that will pass over the joint.  There's a quick guide to our armoured joints available as a download on this page; or use our product selector.  You can always call our technical engineers for help.  Often there will be more than one suitable option, and it may also be that more than one kind of armoured joint or formwork is needed for your project.  We can help you find the best combination.

This depends on the depth of the concrete slab being poured.  Normally you would choose a rail size 30mm less than the depth of your slab – so if your nominal slab depth was 190mm you would use a 160mm high joint.

Firstly, it's to allow for variances in the sub-base.  The sub-base usually has a tolerance of +/- 1cm; so if the sub-base is created slightly out of tolerance, there is still space for the joint to move freely. The joint will not work if it is dug into the sub-base.

Secondly, it gives a tolerance for levelling the surface.

All Permaban joints are designed to allow a gap underneath them. This means that the dowel within each product is set below the centre-line of the joint.  If you are unsure, you can measure this on site.  Measure from the edge of the joint to the dowel on both sides: the greater distance will always go to the top.

If in doubt, installation instructions are included with the ‘spares kit’ that is supplied with each bundle of joints delivered to site.

Dowels bear and transfer the load between two sections of concrete slab – which means weight can move across the finished floor without causing stress in the concrete slab.  A concrete slab typically only has about 50% of its weight-bearing properties at the edge of a slab. So dowels help to support the slab at the edges to bear and transfer weight from one slab to another, allowing both the "approach and leave" slabs to flex slightly so the weight can move smoothly across the surface.

Dowels are needed in instances where there is a formed joint installed (such as one of our armoured joints), or where aggregate interlock alone cannot be relied upon to transfer the weight  between the "approach and leave" slabs.

You’ll find we supply two kinds of dowel – square dowel bars and plate dowels.  Both types are efficient at load transfer between concrete slabs. 

Most of our armoured joints use plate dowels, because they are very reliable, allow controlled two-way lateral movement of the concrete, but completely stop any vertical movement, to ensure a level surface. 

However, square dowel bars are also a good choice.  Unlike round dowel bars, our square dowel bars allow two-way lateral slab movement, while still preventing vertical movement.  Installation is important, so that the dowels are level and parallel with each other, to prevent cracks from occurring – but (unlike round dowel bars) our square dowel bars are designed to absorb small installation variances. 

If the plate dowel sleeves were square they would only allow slab movement in one direction: horizontally, but not laterally. Because concrete shrinks towards the centre of the slab, limiting the lateral movement would create unwanted stresses in the slab.  Our plate dowel sleeves are designed to allow concrete movement both horizontally and laterally (but not vertically).

Dry-shake is a granular substance, which is shaken evenly over the concrete while it is curing.  Dry-shake offers several benefits.  It enhances the durability of the floor, and can add texture, or help the floor to reflect more light.  Different colours may be used to designate different areas of the floor for example - or just to improve appearance.  

Essentially, their composition. 

We’re currently planning some exciting changes to our dry-shakes range.  More information will come soon – but please get in touch with us if you’re interested in specifying or buying dry-shakes, and we’ll be happy to discuss this with you.

Yes we can.  We have a range of standard colours, but can provide dry-shake in a specific corporate colour if required.  Please talk to us about your requirements at the earliest opportunity.

Firstly the product - you can use our product selector to help guide your choice, or talk to us for help.  We will need to know how many metres of product you need.  We also need to know the slab depth.  

Although we strongly support our distributor network, we do have some 'house accounts' where customers buy direct from us.  This is usually where customers have very specific or ongoing requirements where we can provide the best service by looking after the account direct.  Contact our sales team on +44 1752 895288 if you'd like to discuss this further.

Yes we can.  Take a look at our case studies section, and you'll see an example of a product we developed specifically for First Group, where the application required a particular bespoke solution.  If you think a special product may be required, it's best to speak to our sales team or technical engineers for guidance as soon as possible.  It may be that we have already developed a product not featured on this website that would meet your needs.

We're always happy to discuss new opportunities with companies.  It's best to call us in the first instance.  We'll need to know some information about your company, including how long you've been trading, where you operate geographically, and which segments of the market you mainly deal with.

Floor repairs can be carried out by Permaneo, the flooring repair and maintenance brand from RCR Flooring Services. It offers crack repairs, joint repairs (using the Permaban Signature AR joint repair system), resurfacing, polishing and maintenance services.  Contact us on +44 1752 895288 for information.

All our products conform to the Construction Products Regulation (Regulation (EU) No. 305/2011), and hold appropriate CE marking. Some of our products carry the CE mark, and some do not need to.  Please visit our Regulations and Standards page for more information.

technical support

Our team is here to help you at every stage - from questions about product choice, right through to installation. We'll even attend pre-works meetings with you, to help make sure things go smoothly on site. Call our technical team on +44 1752 895288 for more information.


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ask our experts!

If you don't find the information you need here, call our team on +44 1752 895288 - or send us an enquiry using the form below.

Key People

Jenny Stanbury

Jenny Stanbury

Sales Administration Manager

+44 1752 895288

Lee Brockway

Lee Brockway

Managing Director

+44 7525 984729

Ibrahim Fleyfel

Ibrahim Fleyfel

European Distributor Manager

+44 7921 056851

Steve Swan

Steve Swan

Sales Executive - UK

+44 7703 883386

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