A row of new build houses in Chesterfield, each with a flat roof terrace guarded by glass. The run is our parapet wall glass balustrade, fixed so that nothing goes through the waterproof covering on the roof.
Surveyed with the developer, made in our Sheffield workshop and installed by us across the terrace.
Project overview
- Client type: Residential new build development
- Location: Chesterfield, Derbyshire
- Scope: Survey, supply and installation
- Product: Parapet wall glass balustrade
- Arrangement: Two substantial horizontal rails with clear glass infill
- Fixing: Side mounted to the parapet, so nothing penetrates the roof covering
- Roof: GRP waterproof covering, left intact
- Finish: Powdercoated steelwork
- Fabrication: BS EN 1090-2, execution class EXC2, declaration method 3b
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This is our parapet wall glass balustrade, made for guarding a flat roof or terrace without putting fixings through the waterproofing.
The problem with guarding a flat roof
A flat roof terrace needs guarding, and guarding needs fixing to something. The obvious thing to fix to is the roof deck, which is also the one surface on the building you least want to drill.
A GRP, EPDM or bituminous covering is a continuous membrane, and its value is in being continuous. Every bolt through it is a joint that has to be sealed, and every sealed joint is a thing that can fail quietly for a few years before anybody notices the ceiling below. On a new build the roofer's guarantee is usually gone the moment somebody else puts a fixing through it.
So the balustrade here does not touch the roof. It is fixed to the side of the parapet instead, and the loads go into the structure of the wall rather than into the deck.
Where the fixings go instead
There are three ways to guard a flat roof without going through the covering, and which one you get depends on what the roof is built out of.
Side fixed to the parapet. What was used here. Brackets bolt into the face of the upstand, the load goes into the wall, and drainage across the roof is untouched.
Fixed to the structure under the covering. Where there is no parapet, posts can sometimes come off the structural deck with the waterproofing dressed up and over the base, which is detailed with the roofer rather than around them.
Ballasted. A free standing frame held down by weight. Useful on a roof where nothing can be fixed at all, and heavier and more expensive than it looks.
Which one applies is decided at survey, and it is worth asking the question before the roof is finished rather than after.
Two rails with glass between
This is not a frameless system. It is two substantial horizontal rails with clear glass infilling between them, which is a deliberate choice on a parapet job.
Side fixing means the load path runs through brackets into the face of a wall, and a framed arrangement spreads that across several fixing points rather than concentrating it the way a frameless channel does. It also keeps the glass panels replaceable, which on an exposed roof terrace is worth having.
The steel is powdercoated, so it can be matched to the windows or the fascia. Clear glass keeps the view, which on an elevated terrace is the reason the terrace exists.
What a particular terrace needs by way of guarding height and loading is set by your designer and your building control officer. Our glass balustrade building regulations guide covers what they will be looking at.
Get a price for something similar
Send a photograph of the roof and the parapet, the length of each run and a note of what the covering is, to sales@diomet.co.uk, or call 0114 243 9009. Tell us whether the roof is finished, because it changes what we can fix to.
- Parapet wall glass balustrade, the system on this job, priced online
- System 7 side fixed frameless glass balustrade, the frameless way of fixing to a face rather than a deck
- System 9 galvanised steel glass balustrade, for an exposed roof where galvanising is wanted under the paint
- System 10 powdercoated glass balustrade, the posted version in a RAL colour
- Raised glass wind screens and privacy screens, where a terrace is overlooked or exposed
- 12mm clear toughened glass panels, if you only need replacement glass for a frame you have
If you are not sure which of those fits, our how to get a price page sets out exactly what we need from you.
Before you order
- Glass balustrade building regulations
- Balcony building regulations
- Material finishes
- Installation
- Product maintenance
- Our certification and what it covers
Frequently asked questions
Can a balustrade be fitted to a flat roof without drilling the waterproofing?
Usually yes. Side fixing to a parapet is the normal answer, and it keeps the covering whole. Where there is no parapet, the options are fixing to the structure under the covering with the membrane dressed over the base, or a ballasted frame. It is decided at survey.
Will it invalidate the roof guarantee?
Putting fixings through a covering usually does, which is exactly why we avoid it. If the roof is already installed and under guarantee, tell us who installed it and we will specify something that does not interfere with it.
Why two rails and glass rather than frameless?
Because of how it is fixed. Side mounting puts the load into the face of a wall through brackets, and a framed arrangement spreads that across several points. It also means a damaged panel can be swapped without rebuilding the run.
Can it be done on an EPDM or bituminous roof?
Yes. The covering makes no difference to the principle, only to the detail. The question is always what we can fix to without going through it.
Do you work with developers on multiple plots?
Yes. This was a row of new builds done as one order, which is the cheapest way to do it because the setting out and the sections repeat.