Which width of flashing tape do I need?
Supraseal® weatherproofing tape comes in four widths: 50mm, 100mm, 200mm and 300mm. Picking the right one is the difference between a repair that lasts the full 10-year warranty and one that lifts at the edges. Here's how to choose.
The one rule: overlap on every side
Whatever you're sealing, the tape needs to reach well past the defect on every side so it bonds to sound, clean material. As a rule of thumb, allow at least 50mm of overlap beyond the split, hole or joint all the way round. So measure the defect, add 100mm (50mm each side), and pick the next width up.
Width by width
50mm: small, neat details
- Nail and screw holes, pinholes and small punctures
- Pipe and cable penetrations
- Fine cracks and short seam touch-ups
- General repairs around the house, van or caravan
Sold in 5m rolls. The one to keep in the van for quick fixes.
100mm: the maintenance all-rounder
- Short seam and lap repairs on single-ply membranes
- Gutter joints and leaking gutter seams
- Narrow joints and trims on modular buildings and site cabins
- Splits up to around 50mm wide
Sold in 5m rolls. A handy width for general maintenance and smaller repairs.
200mm: the single-ply and modular workhorse
200mm is the width single-ply membrane installers and modular building manufacturers reach for most. It's wide enough to bridge a joint or detail with a full lap onto sound membrane each side, and it's the standard for:
- Sealing laps and seams between single-ply membranes (EPDM, TPO and PVC), including joints between dissimilar membranes
- Bay joints and module-to-module joints on modular buildings, site cabins and welfare units
- Upstand and abutment details where the membrane meets a wall or parapet
- Internal and external corners, outlets and penetrations on single-ply roofs
- Larger splits and tears in membranes, and lead-free flashing repairs
Sold in 5m and 10m rolls. The 10m roll is the better buy for installers and production lines working joint after joint.
300mm: wide details on single-ply and modular roofs
300mm is the choice when a detail needs a deeper turn-up or a wider lap than 200mm allows. Single-ply contractors and modular manufacturers use it for:
- Deep upstands and parapets, with a generous turn-up onto the wall and a full lap onto the roof membrane
- Wide bay joints and roof-to-roof junctions between modules
- Large patch repairs on single-ply and other flat roofs
- Gutter linings, valleys and wide flashings onto brick or render
- Covering several defects close together in one pass
Sold in 10m rolls.
Quick reference
| Defect or detail | Recommended width |
|---|---|
| Nail hole, pinhole, penetration | 50mm |
| Gutter joint, short seam repair | 100mm |
| Split up to 50mm | 100mm |
| Single-ply laps and seams, modular bay joints | 200mm |
| Split 50–100mm, upstand, abutment, corners | 200mm |
| Deep upstands, wide module joints, large patches | 300mm |
| Split over 100mm, gutter linings, wide flashings | 300mm |
Still not sure?
Email hello@supraseal.com with a photo of the job and we'll tell you which width, and how much, you need. Buying for a crew, a production line or a merchant counter? Ask about trade pricing on bulk and pallet orders.