Water-Based Black Waterproof Membrane System | Match Your Roof's Condition First

Get the waterproofing wrong once, and every rainstorm becomes a stress test. Water-based EVA polymer-modified rubberized asphalt membrane — German-formula, low VOC, thick-film formation, crack-following capability. Ideal for old roof renovation, complex joint repair, and situations where both budget and efficiency matter.

Match Your Roof's Problem First

What You're Seeing	What It Means	What Needs to Be Done
Indoor leaking after rain	Waterproof layer aged or joint detail failed	Joint reinforcement + full membrane rebuild
Old membrane bubbling / cracking	Substrate moisture or UV degradation	Add white reflective topcoat or full renewal
Water seeping near gutters or drains	Poor edge sealing or missing reinforcement strip	Reinforcement fabric layer + contoured drainage sealing
Leaking at inside corners or pipe penetrations	Joint areas not reinforced with fabric	Polyester non-woven / fiberglass tape reinforcement
Top-floor rooms extremely hot in summer	Black roof surface absorbing large amounts of heat	Apply white high-reflectance weatherproof topcoat
Metal roof seam joints leaking	Metal corrosion or aged silicone sealant	Rust removal + degreasing + metal primer + membrane

4 Things to Confirm Before Work Begins

Skip any one of these and problems will appear after completion.

1. Moisture content — Substrate moisture must be ≤ 8–12%. Exceeding this causes immediate bubbling and delamination. Allow sufficient drying time after rain before any work begins.
2. Substrate type — RC concrete, metal sheeting, old black membrane, and old asphalt each require a different primer. They are not interchangeable.
3. Joint locations — Inside corners, pipe penetrations, floor drains, and expansion joints are the source of 90% of all leaks. Each must be individually reinforced.
4. Residual silicone — Old silicone sealant residue must be fully removed before application. New membrane will not bond over it.

System Construction | 4-Layer Protection Logic

Layer 1 | Substrate Preparation

High-pressure cleaning → remove loose coating → degrease → remove old silicone → V-groove crack cutting + resin fill Joint details first: inside corners, pipe penetrations, and floor drains get polyester non-woven / fiberglass tape reinforcement strips before membrane application

Layer 2 | Primer (Selected by Substrate Type)

Substrate Type	Required Primer
Concrete / powdering mortar surface	Modified acrylic cement-type bonding agent — penetrating seal
Metal (steel sheeting / galvanized)	Metal-specific anti-rust primer (phosphate or zinc-based)
Smooth glazed tile surface	Tile-type bonding adhesive agent

Layer 3 | Main Black Membrane Application

Key rule: Multiple thin coats — never apply thick in a single pass (surface dries while interior stays wet, causing blistering)

Protection Level	Coverage Rate	Number of Coats	Dry Film Thickness
Standard roof	1.5–2.0 kg/m²	2–3 coats	Approx. 1.0–1.5 mm
High protection (gutters, ponding-risk areas)	2.5–3.5 kg/m²	3–4 coats	Approx. 1.5–2.0 mm

Inter-coat waiting time: surface-dry in approx. 1–3 hours — proceed when touch-dry and no longer tacky Full cure: allow 48–72 hours before exposure to prolonged standing water

Layer 4 | White Reflective Weatherproof Topcoat (Strongly Recommended)

In Kaohsiung's intense UV environment, black membrane exposed directly to sun will degrade prematurely. Adding white high-reflectance topcoat (acrylic / silicone resin / fluorocarbon): ✔ Reduces surface temperature by 10–20°C ✔ UV-resistant ✔ Anti-fouling ✔ Significantly extends service life ✔ Simultaneously reduces heat load in top-floor rooms

Black membrane + white reflective topcoat = one of the most stable roof configurations for southern Taiwan

Standard Construction SOP

1.  High-pressure cleaning (removes dirt, loose coating, old silicone)

2.  V-groove crack cutting + resin injection fill

3.  Joint reinforcement strips (non-woven fabric / fiberglass tape)

4.  Primer application (matched to substrate type)

5.  Black membrane — 1st coat (roller or brush application)

6.  Reinforcement fabric placement (over crack zones, corners, slab joints)

7.  Black membrane — 2nd coat (applied in crossing direction)

8.  3rd–4th coats as required by protection level

9.  White reflective weatherproof topcoat — 2 coats

10. Floor drain and gutter edge sealing + metal cover strip

11. Post-completion water-spray leak test (30–60 minutes continuous)

Weather requirements: temperature 5–35°C, relative humidity < 85%, no rainfall within 6–8 hours after application

6 Common Failures — Almost All Preventable

Failure	Cause	Prevention
Bubbling, whitening, delamination	Substrate moisture content too high	Measure before work — wait out rainy season windows
Blistering after sun exposure	Single thick coat — surface dry, interior wet	Multiple thin coats, confirm inter-coat drying
Joint leaks recurring	Inside corners and pipe penetrations not reinforced	Non-woven or fiberglass fabric layer — mandatory
Metal surface delaminating quickly	Applied over undegreased or rusted metal	Grind to bare metal sheen + metal-specific primer
Membrane degrading early	Direct intense UV exposure in southern Taiwan	Apply white reflective topcoat
Floor drain backflow leaking	Poor edge sealing	Reinforcement strip + contoured drainage detailing + metal cover strip

Check These 5 Points Before Final Sign-Off

1. Visual inspection — No pinholes, no drip marks, no uncovered areas, uniform overlaps throughout
2. Film thickness — Dry film spot-check measurement, or verify against material consumption vs. area (±10% tolerance)
3. Adhesion — Cross-cut test (ASTM D3359) grade 0–1; pull-off test where required
4. Water-spray test — 30–60 minutes continuous spray, with focused checks at gutters and floor drains
5. Joint photo documentation — Reinforcement fabric, inside corners, pipe penetrations, parapet wall edge capping, and drain collar details must all have construction records

Pricing Reference

Actual quotes vary based on roof area, joint complexity, substrate condition, and building height.

Work Item	Reference Price
Standard roof waterproofing (2–3 coats black membrane)	Approx. NT$ 800–1,800 / ping
High-protection level (3–4 coats + reinforcement fabric)	Approx. NT$ 1,500–2,800 / ping
White reflective weatherproof topcoat (add-on)	Approx. NT$ 300–600 / ping
Joint repair (gutters, pipe penetrations, corners)	Priced per location — quoted separately
Metal roof rust removal and primer surcharge	Based on corrosion severity — quoted separately

Copy & Send This to Any Contractor When Requesting a Quote

I need a water-based EVA polymer-modified rubberized asphalt membrane roofing waterproofing system. Please provide:

1. Product TDS / SDS: solid content, VOC, elongation rate, tensile strength, low-temperature flexibility, water impermeability data
2. Design coverage rate and dry film thickness (standard areas / gutters / joints — listed separately)
3. Primer recommendations (concrete / metal / tile — each matched separately) + reflective topcoat recommendation
4. Construction SOP: inter-coat intervals, temperature/humidity limits, post-rain waiting time
5. Reinforcement fabric specs: weight per m², width, overlap method
6. Itemized quote: substrate preparation / primer / membrane / fabric / topcoat / edge sealing / debris removal
7. Warranty terms: water leakage / adhesion / powdering — years covered for each
8. Kaohsiung-area project references (coastal / high-UV environments) with photos

When requesting a quote, please provide first: roof area, substrate type (RC / metal / old asphalt), current problems (leaking / cracking / heat), and whether the location is coastal or severely west-facing.