When a door is heavy, everything about it works harder: the frame, the fixings, and especially the hinges. Get the hinge choice right, and that door will open smoothly for years to come. Get it wrong, and it’ll start to sag, strain the frame, and fail long before its time.
So, how do you make sure hinges can handle the weight? Here’s a straightforward guide to choosing the right hinge for heavy internal doors.
Start with the Door Weight
Before choosing a hinge, you need to know what it will be supporting. The door weight is the first thing to check. And not just the door, but also the ironmongery fitted to it. A solid timber door with a closer, glass vision panel and kick plate can easily weigh twice as much as a hollow-core version.
As a quick rule:
- Light internal doors (under 40 kg) can use standard-grade hinges.
- Medium to heavy doors (60–100 kg) need Grade 12–13 hinges.
- Extra-heavy doors (100 kg+) require Grade 14 hinges tested to BS EN 1935.
Tip: Hinges tested to the standard BS EN 1935 hinge grades have proved that they can work up to 200,000 cycles, a good indicator of durability under real-world use.
Think About Frequency of Use
A hinge that carries a door in a quiet office won’t face the same strain as one in a busy corridor or hotel. Frequent use means more wear, so look for:
- Concealed bearing hinges, which reduce friction and are completely maintenance-free.
- Hinges with tested durability ratings: for example, Grade 13, which covers high-traffic or heavy-use doors.
Concealed bearings not only make the hinge last longer, but they also make the door feel more comfortable to use.
Choose the Right Material
For internal doors, stainless steel is often the best all-round option. It combines strength, corrosion resistance, and a clean finish.
Other materials to consider:
- Mild steel: strong and cost-effective for dry indoor areas in more industrial settings.
- Brass: good where appearance matters and the door isn’t heavily used.
- Other finishes: plated, polished, or powder-coated options can match surrounding hardware and fixtures.
If the door is near a kitchen, bathroom, or plant room, a stainless hinge helps prevent tarnishing and sticking over time.
Get the Hinge Count Right
For most internal doors up to 2.2mm high, three hinges are standard, but heavier or taller doors may need four or even five to distribute the load properly.
A good rule of thumb:
- ≤ 2200 mm: 3 hinges
- 2200–2800 mm: 4 hinges
- 2800 mm +: 5 hinges
Adding an extra hinge is a small cost that can prevent sagging or warping later.
Match the Hinge to the Job
Once you know the weight and number of hinges, look for models that can handle the calculated load plus a safety margin (usually + 20%).
For example:
A 100 kg door on three hinges = 33 kg per hinge.
Add 20% = 40 kg minimum per hinge load rating.
Check the load data on the Phoenix Hinges product page, each hinge lists its capacity, grade, and test certification.
Don’t Forget Fire Performance
If your heavy internal door is also a fire door, the choice of hinge is critical. You’ll need CE-Marked hinges tested to BS EN 1935 and approved as part of a fire-tested door set.
Only hinges that carry the correct marking and test evidence to work with its door set can be used on fire doors, even internally.
Installation and Aftercare
A good hinge can still fail if it’s badly installed, so make sure:
- The screws are the right type, size and length.
- The hinge knuckle is aligned with the door edge.
- The fixings are tight but not overtightened.
- The door is supported evenly while fitting.
Common Mistakes to Avoid
❌ Using the same hinge on every door: heavier, higher-usage doors need higher grades.
❌ Forgetting the weight of door hardware.
❌ Assuming all hinges marked “fire rated” are equal: check the test evidence.
❌ Fitting only two hinges on tall or heavy doors.
Small oversights like these are what lead to sagging, scraping, and premature failure.
Why It Pays to Choose Carefully
Choosing the right hinge isn’t complicated; it just comes down to balancing the door weight, usage, and environment. At Phoenix, every hinge is selected or manufactured to meet the appropriate British and European standards, with grade, material, and test data clearly listed. That makes it easy to match the hinge to the job and be confident it’ll last.
If you’re unsure which hinge you need, please speak with the Phoenix team. We’ll help you find a tested, durable option that keeps heavy internal doors moving smoothly for years.
Frequently Asked Questions
Q1: What type of hinge is best for heavy internal doors?
A: The best hinges for heavy internal doors are Grade 13 or Grade 14 concealed bearing hinges tested to BS EN 1935. These are designed to handle higher door weights, provide smoother movement, and reduce wear over time.
Q2: How many hinges do I need for a heavy internal door?
A: Most heavy internal doors need three hinges, but tall or extra-heavy doors may require four or five to distribute the weight evenly and prevent sagging. As a guide, add an extra hinge for doors over 2200mm high.
Q3: How do I calculate hinge load capacity?
A: Divide the door weight by the number of hinges to find the load per hinge, then add a 20% safety margin. Choose a hinge that exceeds this adjusted load to ensure safe, long-term performance.