What size window trim do I need?
Choose a trim wider than the gap it must hide, with enough face to sit firmly on both the frame and the wall. Measure the widest part of the gap along the frame, then pick the nearest wider profile. Sizes vary by maker, so check the range you stock.
What sizes are common?
One major profile maker lists these in 2.5 m lengths:
| Trim | Sizes |
|---|---|
| Quadrant | 12 mm, 19 mm |
| Edge fillet | 20 mm |
| D mould | 25 mm |
| Architrave | 45 mm, 60 mm, 90 mm |
How do you pick the right trim?
- Small neat gaps inside: quadrant or D mould.
- Wider reveals or uneven plaster: architrave in a wider size.
- Match the trim colour and finish to the frame.
What if the gap changes along the frame?
Gaps are rarely even, so measure at several points and size for the widest. If a trim is too narrow, it leaves exposed edges and a poor seal. Fix with trim adhesive or pins, then seal the edges.
MLI Building Products stocks window trims and architrave for installers at our Worthing counter, with free delivery within 30 miles.
Need a trade price? Call the trade counter on 01903 262 636 or visit us at Unit 1, Friar Walk, Worthing. We offer free delivery within 30 miles.
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