Case study · Tachbrook Park, Warwick CV34
Like-for-like: why the RTS 88 is the right swap for an RTS 85
Dorma’s RTS range has been the standard concealed transom closer in British aluminium shopfronts and office entrances for decades, which is why we see so many RTS 85s in doors of this age. The good news for a building owner is that the current RTS 88 is dimensionally the same: same body length, same fixing pattern, same spindle position. That means a replacement is a straight swap inside the existing transom box — no cutting the frame, no packing plates, no re-siting the arm. The two units are photographed side by side on this page, the 1990 casting next to its replacement, and apart from the finish they are near-identical.
What we never do is put a new closer onto an old arm. The arm and its slide channel wear with the closer — the pivot bush in the arm opens up, the channel end stops chip, and a worn arm loads a new closer unevenly from day one. The Digisourced door got a new arm and channel with the RTS 88, and the whole assembly was set for a 105-degree non-hold-open swing, closing speed and latching action. That is what a like-for-like replacement should mean: the same door, back to how it worked when the building opened.
Reading the date on a transom closer
Dorma cast a month and year into the body of every RTS unit, which is why we can say this one was made in 1990 rather than guess. It is worth knowing on an aluminium door of any age: a closer past twenty-five years that has started to slam, creep or drift out of adjustment is not going to respond to a service, and budgeting for the replacement before it fails outright avoids the day when the entrance is out of action. If you can photograph the body of your closer with the transom cover off, we can date it and tell you whether it is worth keeping.
Work completed at Digisourced
- Survey — closer identified as an original Dorma RTS 85 (1990); like-for-like RTS 88 specified.
- Transom closer — leaf removed; RTS 85 and arm stripped out; new Dorma RTS 88 fitted in the existing transom box.
- Arm and channel — new arm and top-rail slide channel fitted to the leaf.
- Commissioning — leaf re-hung on its pivot; 105° non-hold-open, closing and latching action set; door tested from inside and out.
Commercial door engineers for Warwick, Leamington Spa and south Warwickshire
Tachbrook Park, Heathcote and the Warwick Technology Park are all inside our regular Coventry and Warwickshire run, together with Leamington Spa town centre, Kenilworth, Stratford-upon-Avon and Southam. Office buildings on these estates were mostly fitted out in the 1990s and 2000s, so Dorma, Axim and Adams Rite closers, floor springs and pivots from that era are a large part of our work here. Send a photo of the fault and we will quote from it, usually the same day.
