Fits the lower rear opening of Timloc telescopic underfloor ventilators to handle cavity widths from 50–150mm, or internal walls over 100mm thick up to 200mm maximum. Available in multiple colours to match common brick and block finishes.
The Timloc underfloor vent rear extension is the piece that makes the telescopic system actually work across the full range of cavity widths you encounter on site. It slots into the lower rear opening of the Timloc telescopic underfloor ventilator and extends its reach to accommodate cavity widths between 50mm and 150mm, or internal walls thicker than 100mm, up to a maximum of 200mm. Without it, you are limited to what the ventilator alone can span — and cavity widths are rarely consistent enough to assume you will not need one.
Underfloor ventilation is one of those jobs that does not get a lot of attention until there is a problem. Suspended timber floors need a steady movement of air beneath them to prevent moisture build-up, which leads to rot, swelling, and in bad cases, structural damage. Getting the ventilator to actually bridge the cavity properly is the part that matters most, and that is exactly what this extension is designed to do. It is a simple component, but the right one makes all the difference between a properly functioning vent and a bodge that leaks cold air around the edges.
Where the Timloc Rear Extension Fits In
Timloc’s telescopic underfloor ventilator system is widely used in new builds and renovation work where suspended floors are present. The ventilator itself handles the visible face of the vent, but the rear extension is what allows the internal duct section to be pushed further back through wider cavities or thicker walls. On older properties especially, internal wall thicknesses can vary considerably, and having the extension available means you are not cutting corners or packing the gap with whatever is to hand.
The extension adds 100mm to the rear of the duct, which is enough to bridge the additional depth without compromising the airflow path. It simply locates into the rear of the telescopic body and requires no adhesive or fixings to hold it in place during installation — the surrounding masonry does that job once the vent is built in.
Available in eight colours including white, brown, buff, terracotta, grey, black, blue and black, and clear, so you can match the ventilator face to the surrounding brickwork or render without it looking like an afterthought. Order multiples if you are doing a full perimeter — most suspended floor installations need several vents spaced at regular intervals, and having the right extension for each one is just good practice.
Pro Tip: If you are working on an older property where the internal wall thickness varies from one vent position to the next, measure each opening individually before ordering — it saves a second trip and means every vent sits flush with no gaps.
This rear extension is used wherever Timloc telescopic underfloor ventilators are being fitted through walls with wider-than-standard cavities or thicker internal skins. It is most commonly needed on older properties where wall construction is less predictable, on renovation projects where internal lining has increased the effective wall thickness, and on new builds where cavity widths sit at the wider end of the standard range. Any trade fitting suspended floor ventilation on a project where wall thickness exceeds the basic ventilator span will need this component.
Best For
Wider cavity walls (50–150mm)
Internal walls over 100mm thick
Walls up to 200mm total depth
Suspended timber floor ventilation
New build and renovation projects
Works With
Timloc telescopic underfloor ventilator
Lower rear opening of the ventilator body
Standard cavity masonry construction
Key Features
Adds 100mm rear extension to duct
No adhesive or fixings required
Available in 8 colours
Fits lower rear opening of telescopic unit
Maintains clear airflow path through wall
Not suitable for: Not suitable for use without the corresponding Timloc telescopic underfloor ventilator — this is an extension component, not a standalone vent. Walls exceeding 200mm total depth will require a different solution.
Fit this extension into the lower rear opening of the Timloc telescopic underfloor ventilator before the unit is built into the wall. The extension simply locates into position and is held securely once the surrounding masonry is laid. No adhesive is needed. Check the total wall depth before installation to confirm the +100mm extension will bring the system within the required 50–200mm range.
Measure the total wall or cavity depth at each vent position before starting work.
Confirm the depth falls within the 50–200mm range that this extension accommodates.
Select the correct colour extension to match the ventilator face and surrounding masonry.
Insert the rear extension into the lower rear opening of the Timloc telescopic underfloor ventilator.
Build the ventilator and extension into the wall course at the correct height above DPC level.
Check the duct is clear and the airflow path is unobstructed before pointing up around the vent face.
Which Timloc ventilator does this extension fit?
This rear extension is designed specifically for the Timloc telescopic underfloor ventilator, fitting into the lower rear opening of the duct body. Always check compatibility with the specific Timloc model you are using before ordering.
Do I need one extension per ventilator?
Yes, one extension is required per ventilator where the cavity or wall depth exceeds the standard telescopic range. If you are fitting multiple vents around the perimeter of a suspended floor, order one extension for each position that needs it.
Does the colour affect the function of the extension?
No. Colour is purely aesthetic and is there so the visible face of the vent blends with the surrounding brickwork or render. All eight colour options perform identically in terms of fit and airflow.
The Timloc underfloor vent rear extension is a formed plastic duct component designed to integrate with the Timloc telescopic underfloor ventilator system. It extends the rear duct section by 100mm, allowing the system to span cavity widths between 50mm and 150mm, or accommodate internal wall thicknesses beyond 100mm up to a 200mm maximum. The component is manufactured from uPVC or similar rigid polymer, offering durability in the damp subfloor environment without corrosion or deterioration over time.
Extension Depth
+100mm
Compatible System
Timloc Telescopic Underfloor Ventilator
Cavity Width Range
50–150mm
Maximum Wall Depth
200mm
Fit Location
Lower rear opening of ventilator
Available Colours
Black, Blue & Black, Brown, Buff, Clear, Grey, Terracotta, White
SKU
LOC1206
Colour
Black, Brown, Buff, Clear, Grey, White, Blue & Black, Terracotta
Reviews
There are no reviews yet.
Be the first to review “Timloc Underfloor Vent – Horizontal Rear Extension +100mm (1 pcs)”Cancel Reply
Reviews
There are no reviews yet.