It is one of the questions that comes up most often in roof terrace design: if we drill through the membrane to fix the balustrades, does it affect the waterproofing warranty? The honest answer is that it can, and it is worth understanding exactly how before it becomes a problem on site.
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typical flat roof membrane warranty length
what the warranty covers, not as later modified
penetrations through the membrane with BalcoDeck
BalcoDeck guarantee, from one UK manufacturer
Most flat roof membranes carry warranties between 10 and 30 years. They typically cover defects in materials and workmanship as applied to the membrane installation. What they do not always cover is what happens to the membrane afterwards.
BalcoDeck holds the balustrade structurally without drilling through the waterproofing. If the membrane is never modified after installation, there is no post-installation penetration for a manufacturer to exclude or query.
That is exactly the sequence BalcoDeck is built for. Send us the roof and we will tell you whether it suits a non-penetrative fix.
| Warranty question | Penetrative fixing | BalcoDeck non-penetrative |
|---|---|---|
| Membrane after installation | Drilled and modified | Left exactly as installed |
| Manufacturer penetration conditions | Must be met, or cover is excluded | No penetration to approve |
| Reliance on collars and sealants | Yes, and they age faster than the membrane | None |
| If a leak appears in year eight | Liability argued between trades | Membrane untouched, single point of cover |
| Fits a finished, warranted roof | Requires cutting back into it | Designed for exactly that sequence |
Not always, but they can. It depends on the membrane system and its conditions. Some warranties require penetrations to be pre-approved and detailed a specific way, others exclude them entirely. The safe position is not to modify a warranted membrane at all.
No. Because BalcoDeck sits on top of the finished membrane rather than fixing into the structure, it suits terraces where the waterproofing is already complete and warranted.
With a penetrative detail, a leak can become an argument between the membrane installer and the balustrade contractor. With a non-penetrative system the membrane is untouched, and the guarding and roof interface are covered together under one guarantee.
Yes. The structural loads are transferred through an engineered substructure that distributes them across the roof, so the balustrade meets its guarding duty without an anchor through the membrane.
Not every flat roof is a candidate, and we would rather tell you that early than sell you a survey you do not need.
Guidance on this page is drawn from Balconette's own article, Do Balustrade Fixings Void Flat Roof Warranties? Warranty terms vary by membrane manufacturer and system; always check your specific warranty. BalcoDeck® is manufactured in Surrey by Balconette. UK Patent GB2636232.
Send us your roof details and find out whether BalcoDeck lets you add the balustrade without touching the membrane.