Bitumen Felt Base Mat: Uses & Benefits

WATERPROOF MEMBRANE BASE MAT PROFESSIONAL SUPPLIER

Bitumen Felt Base Mat: Uses & Benefits

People usually employ bitumen felt base mats for waterproofing and roofing purposes. Here’s an FAQ guide covering some critical parts:

1. What is bitumen felt base mat?

Bitumen felt base mat (also called underlayment) serves as a waterproofing membrane in roofing systems. Its base layer consists of either reinforced or non-reinforced bituminous felt. Manufacturers produce it by saturating or coating a host material—such as polyester mat, fiberglass, or organic felt—with bitumen, asphalt, or modified bitumen.

2. What are the types of bitumen felt base mats?

Felt with Reinforcement:Used for greater strength due to fiberglass or polyester reinforcements.
Non-reinforcement (Organic Felt): Made from cellulose fibers. Not very durable, but more elastic
Torch-On Felt: Requires heat (flame) for installation.
Self-Adhesive Felt: Has a peel-and-stick backing for easier application.
Perforated Felt: Allows trapped moisture to escape (used in certain roofing systems).

3. What are the main applications?

Roofing underlayment: Provides a waterproof barrier beneath shingles, tiles, or metal roofing.
Damp-proofing: Used in foundations or below-grade structures.
Flat roof systems: As a base layer in built-up roofing (BUR) or modified bitumen systems.

4. What are the advantages?

Waterproof: Acts as a moisture barrier.
Flexible: Adapts to minor substrate movements.
Cost-effective: Affordable compared to other waterproofing membranes.
Durable: Resists UV (if covered) and weathering.

5. How is it installed?

Surface Preparation: Clean, dry, and smooth the substrate.
Adhesion Methods:
- Torch-applied: Heated with a flame for bonding.
- Cold-applied: Using bitumen adhesive or self-adhesive backing.
- Mechanical Fixing: Nails or staples (for temporary underlayment).
Overlap: Sheets should overlap (typically 100mm side/end laps) for watertightness.

6. What are the key standards?

BS 8217: British Standard for reinforced bitumen membranes.
EN 13707: European standard for reinforced roofing felt.
ASTM D226/D227: US standards for asphalt-saturated felt.

7. How long does bitumen felt last?

Base layer (underlayment): 10–20 years, depending on exposure.
Exposed roofing: 5–15 years (requires protective top layers).

8. Can it be repaired?

You can patch damaged sections with bitumen tape, liquid bitumen, or a new felt layer.

9. What are common issues?

Blistering: Trapped moisture or poor adhesion.
Cracking: Aging or extreme temperature changes.
Poor adhesion: Incorrect installation or dirty substrate.

10. Is bitumen felt environmentally friendly?

Manufacturers produce traditional bitumen from petroleum, but some modified versions use recycled materials.
Alternatives like synthetic underlayment (TPO, EPDM) are more eco-friendly.