🏗️ Everything You Need to Know About Built-Up Roofing (BUR)
When it comes to protecting flat or low-slope roofs, few materials are as tried-and-true as Built-Up Roofing (BUR). This roofing system has been used for over a century — and for good reason. It’s reliable, long-lasting, and provides exceptional waterproofing for both commercial and residential buildings.
In this guide, we’ll cover everything you need to know about built-up roofing — how it works, its advantages, and whether it’s the right choice for your property.
🧱 What Is Built-Up Roofing?
Built-Up Roofing (BUR), often called a “tar and gravel roof”, is a roofing system made up of multiple layers of materials that work together to create a strong, watertight barrier.
A standard BUR system typically includes:
- Base sheets – The first layer applied directly to the roof deck.
- Bitumen layers – Asphalt or coal tar applied between layers for waterproofing.
- Reinforcing fabric – Usually fiberglass or organic felt for added strength.
- Top surfacing – Gravel, mineral cap sheets, or reflective coatings to protect against UV rays and weather.
Each layer is “built up” on top of the other — hence the name.
⚙️ How Built-Up Roofing Works
The main idea behind BUR is layered protection. Every layer adds durability and helps prevent leaks. The bitumen acts as a binder and sealant, while the surfacing layer shields the roof from sunlight, wind, and debris.
This combination creates a tough, seamless barrier ideal for flat or low-pitched roofs, where water drainage can be slow and standing water is common.
🏠 Where Built-Up Roofing Is Used
Built-up roofing is commonly found on:
- Commercial buildings
- Industrial facilities
- Apartment complexes
- Residential homes with low-slope roofs
Its proven performance in extreme conditions makes it a go-to choice for large structures needing long-term waterproofing.
🌟 Key Benefits of Built-Up Roofing
There’s a reason BUR has been used for decades — it works.
Here are the main advantages:
✅ Long-Lasting Protection
When properly installed and maintained, BUR systems can last 20 to 30 years or even longer.
✅ Superior Waterproofing
The multiple layers of bitumen and felt create excellent resistance to water leaks.
✅ UV and Weather Resistance
The top gravel or coating layer reflects sunlight and shields the roof from heat, wind, and impact damage.
✅ Low Maintenance
Once installed, BUR roofs require minimal upkeep compared to single-layer systems.
✅ Fire Resistance
Gravel and asphalt provide natural fire-resistant properties, adding another layer of safety.
⚠️ Potential Drawbacks
While built-up roofing has many strengths, it’s not perfect for every building.
Consider these factors before installation:
- Heavier than other roofing types — requires strong structural support.
- Installation time is longer due to multiple layers.
- Odor and fumes during installation (from hot asphalt) may be unpleasant.
- Not ideal for steep slopes — better suited to flat or low-pitched roofs.
Still, for many property owners, the durability and protection far outweigh the downsides.
🧰 Maintenance and Care Tips
BUR systems are low-maintenance but should still be inspected regularly.
Here’s how to keep your roof in top shape:
- Check for cracks or blisters after extreme weather.
- Ensure drainage systems are clear of debris.
- Reapply reflective coating as needed to maintain UV protection.
- Schedule a professional inspection at least once a year.
These small steps can extend your roof’s lifespan and prevent costly repairs later.
💵 Cost of Built-Up Roofing
The cost of BUR installation typically ranges from $4 to $10 per square foot, depending on:
- The number of layers used
- Roof accessibility and size
- Type of surfacing (gravel, coating, etc.)
While the upfront cost may be higher than single-ply systems, the long lifespan and low maintenance make it a cost-effective option over time.
🏆 Is Built-Up Roofing Right for You?
If your building has a flat or low-slope roof and you’re looking for a proven, long-term solution, built-up roofing is an excellent choice. It offers decades of protection, low maintenance, and superior resistance to leaks and UV damage.
For homeowners or facility managers who value durability and peace of mind — BUR remains one of the most dependable roofing systems available today.
