If you’ve ever worked on a timber project, you’ll know that keeping everything properly secured is essential to making sure the structure stands strong for years to come. Whether you’re building a roof, floor, or wall, even the slightest movement can cause long-term issues with alignment and stability. That’s where restraint straps come in. These simple but powerful metal fixings help prevent movement, twisting, and uplift, keeping timber structures safe and secure.
At RC Screws, we’ve spent years helping builders, tradespeople, and DIY enthusiasts find the right fasteners and fixings for their jobs. We understand that choosing the proper restraint strap can make all the difference to a project’s safety and performance. In this guide, we’ll walk you through what restraint straps are, the different types available, and what to look for when choosing the right one for your timber build.
What are restraint straps?
Restraint straps are strong metal connectors that help hold different parts of a timber structure together. They’re designed to stop walls, floors, or roofs from moving under wind pressure or weight, making sure everything stays in position. Without them, sections of a structure can shift or separate over time, which can lead to serious stability issues and damage.
There are two main types of restraint straps you’ll come across. Vertical restraint straps are used to hold down roof structures or wall plates and protect against uplift from strong winds. Horizontal restraint straps, on the other hand, are used to tie floors and roofs to walls, preventing sideways movement or walls from spreading apart. Both are necessary to keep a structure rigid and safe under load.
Choosing the right strength
Not all restraint straps are built the same, and the right choice depends on what you’re working on. For smaller timber builds like sheds, lightweight internal walls, or non-structural projects, light-duty straps will usually do the job. However, for larger or load-bearing structures like house extensions, roof frameworks, or upper floors, heavy-duty straps are the better option.
Heavy-duty restraint straps are thicker, stronger, and made to handle greater pressure over time. Most are manufactured from galvanised steel, which offers excellent corrosion resistance and ensures long-lasting durability, even in damp or exposed conditions. At RC Screws, we stock heavy-duty bent restraint straps designed for horizontal restraint applications like securing joists or trusses to masonry walls. Each strap is bent at 100mm and made from 4mm galvanised steel, making them tough, compliant, and built to last. They also meet Building Regulations BS 5268 Part 3, giving you extra peace of mind on every job.
What to think about before buying
When you’re choosing restraint straps, a few simple checks will help you get the right one for your project. First, think about the purpose. Are you securing a roof structure or tying floors to walls? Knowing whether you need vertical or horizontal restraint will help narrow down your options.
Next, consider the size. Most restraint straps range between 30 and 50mm in width and around 2.5 to 4mm in thickness. The strap should be long enough to cover at least three timber members, such as rafters or joists, to spread the load properly. The environment also matters.
Galvanised steel straps are fine for most indoor uses, but if you’re working outdoors, in damp conditions, or near the coast, stainless steel is the best choice to prevent rust. And finally, always check that the straps meet UK building standards. Using regulation-approved materials makes sure your work stays safe and compliant.
Getting the installation right
Even the best quality restraint straps won’t perform well if they’re installed incorrectly. To get the best results, make sure you use every pre-punched fixing hole for maximum strength and always fix straps into solid timber, not the ends or edges. The strap should wrap over or around the timber, rather than just sitting flat against it, to give better overall support.
Avoid making any sharp bends when fitting restraint straps because they can weaken the steel and reduce its strength. Instead, create smooth curves wherever you need to adjust the angle. If you’re unsure about fixing positions or spacing, always check the manufacturer’s guidelines or get some advice from a building control officer before you start.
Why quality matters
It’s easy to overlook fixings when planning a build, but they are one of the most important parts of any project. Using sturdy and reliable restraint straps means you’re investing in the strength and long-term reliability of your structure. A good quality strap improves stability and helps reduce the risk of future problems, repairs, or safety concerns.
At RC Screws, we only stock products we trust to perform on site. Our range of restraint straps, fixings, and fasteners is built to meet the demands of modern construction, helping you complete every project safely, efficiently and without delay.
These are just a few things to consider when planning for your next build! Restraint straps might be small components, but they play a huge role in keeping timber structures safe, compliant, and long-lasting. Whether you’re securing wall plates, tying floor joists to masonry, or preventing roof uplift, the right strap makes all the difference.
If you’re not sure which type is best for your next job, our friendly team at RC Screws is always happy to help. Give us a call on 01254 917744 and we’ll help you find the perfect restraint strap for your project!