Tips for Installing Unistrut Effectively

What is a Unistrut System? 

Unistrut is a modular metal framing system commonly used to support mechanical and electrical services. Strut channel is combined with appropriate fittings such as channel nuts to create frameworks without the need for welding.

Channels are available in different profiles, sizes and finishes. This allows contractors to build support systems around the practical and structural requirements of each installation.

Benefits of Unistrut

Unistrut channel support systems offer several useful benefits:

• Components can be assembled and adjusted on site
• Standard systems require no welding
• Different channel profiles suit a range of loads
• Various finishes are available for different environments
• Modular parts make future alterations easier
• Compatible fittings help create consistent support structures
• Channels can support pipework, containment and other services

Common Applications of Unistrut Channel Support Systems 

Unistrut is widely used across construction and the mechanical and electrical sector. Common applications include trapeze supports for cable trays, suspended pipework, HVAC services and frames for electrical equipment.

Channel systems can also support rooftop plant and solar panels. The right arrangement will depend on the design load, supporting structure and conditions at the installation site.

Importance of Effective Unistrut Installation 

Even correctly specified components may not perform as intended if they are poorly installed. Unsuitable anchors or incompatible fittings can lead to movement, deflection and possible failure.

Following the approved drawings and project specification as well as relevant manufacturer guidance helps the finished structure safely carry its design loads. It can also prevent costly alterations once other services are in place.

Planning Before Installation 

Before starting work, make sure the installation area and required components have been checked. Resolving potential issues at this stage is usually much easier than changing an assembled support system. 

Review Project Specifications 

Review the approved drawings, schedules and installation details before setting out the system. These documents should identify the required channel profile, finish, route, support spacing and fixing locations.

Compare the design with the conditions on site. If the planned route clashes with existing services or channels cannot be installed as shown, raise the issue before making changes.

Confirm Load Requirements 

The support system must carry the weight of the services, fittings and any additional loads identified by the designer. Capacity can vary according to the channel profile, thickness, span and orientation.

Refer to the appropriate load tables and project calculations rather than judging a channel by its size or appearance. If the expected loading is unclear, seek guidance from the project engineer or another suitably qualified person.

Select the Appropriate Products 

Choose a strut channel that matches the specified dimensions, gauge and configuration. You will also need to determine whether plain or slotted channel is required.

Consider where the system will be installed. A finish suitable for a dry indoor space may not offer enough protection for an exposed, damp or corrosive environment.

Choose Compatible Fittings and Accessories 

Channel nuts, bolts, washers and bracketry must be compatible with the chosen channel system. Pay particular attention to thread sizes and the intended load of each fitting.

Mismatched parts may not engage properly or allow the connection to be tightened securely. If you are using an unfamiliar combination, check its compatibility before installation begins.

Select Suitable Fixing Methods 

Choose fixings that suit both the expected load and the supporting material. Concrete, masonry, structural steel and metal decking may each require a different type of fixing.

The condition of the substrate matters too. Check the manufacturer’s information for requirements such as embedment depth, hole diameter and minimum edge distances.

Unistrut Installation Best Practices 

Once the system has been planned and the correct parts are ready, following a consistent installation process will help produce secure, accurately positioned supports. 

1. Measure and Mark Fixing Points Accurately 

Set out each fixing point using the approved drawings. Confirm that the route is clear of existing services, then use suitable measuring and levelling equipment to mark the positions.

Recheck the measurements before drilling. A small error at the start of a run can leave later supports out of alignment.

2. Install Supports at the Correct Spacing 

Support spacing should follow the approved design and load information for the selected channel. Increasing the distance between supports may increase deflection and reduce the load the system can safely carry.

Do not apply the same spacing to every installation. The required arrangement will vary depending on channel type and loading.

3. Use the Correct Anchors and Assemble Fittings Properly 

Install anchors in line with the manufacturer’s instructions. This includes drilling to the correct diameter and depth, cleaning the hole where required and maintaining the specified distance from edges.

When fitting channel nuts, make sure their teeth engage properly with the turned-in edges of the channel. Add the specified bolts and washers, then check that each fitting sits squarely before tightening it.

4. Tighten Fixings 

Tighten every fixing with the correct tool. Where the manufacturer or project specification provides a torque value, use a calibrated torque wrench and follow that figure.

Loose connections may move under load. Excessive force can also cause problems by damaging threads, distorting components or affecting the performance of an anchor. Avoid applying one general torque setting to different fittings and bolt sizes.

5. Check Alignment 

Check the channel as work progresses instead of waiting until the entire run has been assembled. Make sure each section is level and positioned at the correct height, with parallel channels remaining evenly spaced.

Accurate alignment helps services sit correctly and avoids placing unnecessary strain on brackets or connections. It also makes the next stage of the installation more straightforward.

Inspection After Installation 

Inspect the system before it is loaded or handed over. Look for missing parts, misaligned channel, loose fixings, damaged finishes and fittings that have not engaged correctly.

Supports and anchors should be positioned as shown in the approved design. Distortion, cracking or unexpected deflection must be investigated before the system is used.

Periodic inspections may also be needed, particularly where the channel is exposed to moisture, chemicals, changing loads or accidental damage. Loose, badly corroded or distorted components should be replaced with suitable parts. Do not attempt an unapproved repair where the condition of a component could affect the structure.

Common Mistakes When Installing Unistrut Systems 

Many Unistrut installation problems begin with poor preparation or the wrong product choice. Common mistakes include:

• Choosing channel without checking its rated load
• Using incompatible channel nuts or fittings
• Selecting anchors that do not suit the substrate
• Leaving excessive space between supports
• Using the wrong finish for the environment
• Failing to include the weight of every supported service
• Installing channels or brackets out of alignment
• Ignoring the specified tightening torque
• Leaving cut edges untreated where protection is required
• Using damaged or corroded components
• Moving supports without approval to avoid other services

Checking the completed system against the drawings and product information can identify many of these issues before it is loaded.

Get Further Help From Lenson Select 

Lenson Select supplies Unistrut products alongside strut channel, bracketry, threaded rods and fixings and fastenings. Cut-to-size channel and bespoke kits are also available, helping contractors order the components they need for a complete installation.

We have more than a century of combined experience and can provide advice and parts for systems of all types and sizes. Plus, enjoy quick delivery and discounts on all orders over £1,000. 

For help selecting compatible products, contact the Lenson Select team, call 0121 553 6699 or email sales@lenson-select.co.uk.