How to Connect a Timber Beam to an SHS Post — A Builder’s Step-by-Step Guide

If you’ve ever stood on a building site staring at a shiny SHS steel post and wondering exactly how you’re supposed to get a timber beam onto it, you’re not alone. It’s one of the most common questions we get from builders across Australia. 

The good news? Done right, connecting a timber beam to an SHS post is straightforward, fast, and doesn’t always require a welder on site. In this guide, we’ll walk you through exactly how to do it — from choosing the right cleat to the fastening method that suits your load requirements. 

What Is an SHS Post, and Why Does the Connection Matter? 

SHS stands for Square Hollow Section — the square steel tube columns you’ll find on verandahs, carports, raised decks, sub-floors and all kinds of residential and commercial builds across Australia. 

Because SHS posts are hollow and square, you can’t just nail or bolt a timber beam directly to the face the way you might with a timber post. You need a purpose-built connector — called a cleat — that grips around the SHS column and gives your beam a solid, engineer-rated seat. 

Get the connection wrong, and you risk beam movement, uplift failure in high winds, or a structure that won’t pass your building inspector. Get it right, and it’s one of the strongest, neatest and most time-efficient connections on site. 

What You Need Before You Start 

Before connecting a timber beam to your SHS post, have these ready: 

• The correct SHS timber beam cleat for your configuration (corner, 2-way, 3-way or top plate — more on this below) 

• Series 500 metal tek screws — 12g × 35mm — minimum 5 per channel leg or use 8mm TRI-FIXX m8 self-drilling screws 

• A drill with a Tek screw driver bit 

• A laser level or spirit level 

• Your beam — pre-cut to length 

• If welding: a qualified welder and 5mm fillet weld consumables 

💡  SHS cleats are pre-fabricated from hot-dip galvanised steel, so no on-site fabrication or cutting is required. They slide straight onto the post — it’s a big time saver compared to having a fabricator weld cleats in a workshop and transport them to site. 

Step-by-Step: How to Connect a Timber Beam to an SHS Post 

Step 1 — Set Your SHS Post 

Make sure your SHS post is plumb, and your baseplate is properly fixed to your concrete pier or pad. The post needs to be secure before you attach anything to it. If you’re using SHS baseplates, ensure the grout has cured, or the tek/weld fixing to the slab plate is complete. 

Step 2 — Slide the Cleat to the Right Height 

This is where SHS timber beam cleats make life easy. The cleat channel is designed to slide up and down the SHS post, so you can position it at exactly the right height for your beam. Use a laser level or tape measure to get it to the correct beam seat height. 

💡  Set all your cleats to the same height before fastening any of them. It’s much easier to adjust a sliding cleat than to move one that’s already screwed in. 

Step 3 — Choose Your Fastening Method 

How you fix the cleat to the SHS post depends on the shear load your beam will carry. Here’s a simple breakdown: 

For most residential verandahs, carports and pergolas, tek screws alone will do the job. Use a minimum of 5–8 series 500 tek screws (12g × 35mm) or TRI-FIXX m8 self-drilling screws through each channel leg — that’s the leg that sits flat against the face of the SHS post. 

⚠️  Don’t use standard roof screws or general-purpose fasteners. You need Series 500 metal tek screws rated for structural steel connections. Using undersized or incorrect fasteners is a common mistake that will fail a building inspection. 

Step 4 — Fix the Cleat to the Post 

With the cleat at the correct height and your fastening method selected: 

1. Hold the cleat firmly against the SHS post face, keeping it level. 

2. Drill your series 500 tek screws through the pre-drilled pilot holes in the cleat channel legs, into the SHS post face. 

3. Work in sequence — don’t fully tighten one side before starting the other. Put a few screws in each leg alternately to keep the cleat square and tight. 

4. Check that the cleat is still at the correct height and square to the post, then fully tighten all screws. 

5. If stitch welding: once all cleats are telexed into position, apply your 5mm stitch welds (40-40-40mm) down the vertical edges of both channel legs. Seal the top edge of the channel with a sealant to prevent water ingress into the post. 

Step 5 — Set and Fix the Timber Beam 

With the cleat secure on the post, it’s time to seat the beam: 

6. Lift or manoeuvre your pre-cut timber beam into the cleat seat. The beam should sit snugly in the cleat without needing to be forced. 

7. Check your beam is level and at the correct height. 

8. Fix the beam to the cleat using the specified fasteners (typically structural bolts through the cleat face into the beam end — refer to your product’s installation notes or engineering certification for the correct fixings). 

9. Where two beams meet at the same post (2-way or 3-way configuration), set and fix both beams before moving on. 

💡  If your beam height needs minor adjustment after installation, SHS cleat packers are available to fine-tune the beam seat height without having to reposition the entire cleat. 

Choosing the Right Cleat for Your Application 

Not all beam connections are the same. Here’s a quick guide to the main SHS timber beam cleat types and when to use each: 

If your beam is a steel PFC (parallel flange channel) rather than timber — common in higher-load applications and commercial work — use an SHS PFC beam cleat instead. The installation process is similar, but the product is designed for a different profile of a steel channel beam. 

Common Mistakes to Avoid 

Using the wrong fasteners. Standard screws won’t cut it. Always use Series 500 metal tek screws (12g × 35mm) or TRI-FIXX M8 screws and the correct structural bolts specified in your product’s engineering documentation. 

Not checking the cleat height before fastening. Slide all your cleats to the right height and verify with a level before committing any screws. Repositioning a fully fixed cleat wastes time and can damage the galvanised coating. 

Ignoring the load rating. Tek screws alone are fine up to around 50 kN shear load. If your project is in a high-wind zone, near the coast, or carries heavier loads, check your engineering certification and add the stitch weld or use TRXX screws if required. 

Skipping the sealant on welded connections. If you stitch weld, always apply sealant along the top edge of the channel where it meets the SHS post. Without it, water can pool inside the hollow section and cause corrosion over time. 

Using non-galvanised products in coastal areas. All SHS cleats should be hot-dip galvanised for any project within a few kilometres of the coast or in high-humidity environments. Standard paint or zinc coatings won’t hold up. 

Do You Need an Engineer for a Timber Beam-to-SHS Post Connection? 

For straightforward residential applications — a verandah, carport, pergola or deck — a standard engineer-certified SHS cleat with documentation will satisfy your certifier or building inspector without needing a custom engineering report. 

SHS cleats come with engineering design certifications issued by registered structural engineers (RPEQ / NER qualified), along with full shear and uplift test reports. These documents cover the connection for the standard configurations and fastening methods described above. 

For unusual configurations, very high loads, or building in cyclone regions (wind zones C or D), it’s worth having a structural engineer review the specific connection before you build. 

💡  You can purchase engineering design certifications (covering 1–4 connections or 5–10 connections) directly from shscleats.com.au — ideal for building approval submissions. 

▶  Shop SHS Timber Beam Cleats  |  ▶  View Installation Guide  |  ▶  Contact Our Team for Project Advice