Floor rubber for sectional garage door: Choosing the right Opto, DW & 8k2
A sectional garage door that doesn't seal properly at the bottom is like a window left ajar – only bigger and more expensive. You'll notice it through drafts, dust, dampness, insects, or (the classic) mice, who suddenly seem very convinced that your garage is now "their" garage.
And then there's the second issue: safety. If the bottom rubber and closing edge don't align, the gate will stop, reverse while closing, or display error messages. This isn't just annoying – it costs time, money, and, in commercial settings, a lot of nerves.
This guide provides clear decision-making support: Opto, DW, or 8k2 – what's what, how to identify them, which dimensions matter, and how to mount them properly. It also includes tables, checklists, troubleshooting tips, and practical advice. The goal: choose the right one time – and then have peace of mind.
Contents
- Why floor seals are more than just “comfort”
- Quick check: What did you install (in 2 minutes)?
- Gate systems: Opto, DW, 8k2 – briefly explained
- Opto-system: how to recognize it & what it includes
- DW system (pressure wave): chamber dimensions, plugs, connections
- 8k2 system: resistance, connection, typical errors
- Comparison table: Opto vs DW vs 8k2
- Floor rubber vs. gap seal vs. threshold
- Measuring without guessing: these 7 points are decisive
- Compatibility by manufacturer: Hörmann, Crawford, Novoferm & Co.
- Product types: Bottom rubber seals, top rubber seals, side seals
- Safety before assembly: what you need to consider
- Replacing floor rubber: step-by-step
- Opto: Cleanly resolve cable/sensor routing
- DW: Properly inserting plugs and ends
- 8k2: Start/End Connection & Testing
- Top rubber seal & side seal: when is it worth it?
- Error patterns: Gate stops, reverses, doesn't seal
- Maintenance: This is how the seal lasts significantly longer
- Practical examples: 3 typical everyday situations
- Jump to relevant categories
- Here's how to proceed (short & effective)
- FAQ
- Next step
Tip: If you're currently experiencing an "acute" problem (the goal is annoying), start with Quick Check → Measure → Error Patterns.
Why floor seals are more than just “comfort”
✅ Tightness & Energy
- Less draft, less cold, less humidity
- Less dust in the building (workshop/production notices this immediately)
- Improved indoor climate – a real advantage, especially in heated halls.
🛡️ Safety at the bottom
- The closing edge must fit the system (Opto/DW/8k2)
- Incorrect profile = malfunctions when closing
- In industry: no experiments – thoroughly test, thoroughly assemble.
🐭 Protection against pests
- The gap at the bottom is the invitation
- Proper sealing = fewer rodents/pests
- Especially important for storage, food, and workshops
Pro tip (because it's often forgotten)
When sealing the bottom, also check the mechanics: does the gate run smoothly without jerking? Wear parts such as rollers, roller brackets and hinges are often the reason why seals rub "strangely".
Ball-bearing casters | Caster holders & hinges
Quick check: What did you install (in 2 minutes)?
1) Opto (Optosensor)
You'll usually see a cable routing/“sensor area” in the profile. Often, the sensors are housed in a separate compartment.
Optometry is frequently used in modern systems – but only if the profile and sensor technology match.
2) DW (pressure wave)
A typical feature is a round chamber (e.g., 25/37 mm) for the pressure wave. This includes plugs/ends.
If plugs are missing or incorrectly positioned: adverse reactions are inevitable.
3) 8k2 (8.2 kΩ)
This concerns an electrical safety edge with a resistor. Start/end connections are relevant.
8k2 is technically sound – but only if the connection and testing are correct.
If you're unsure: do it smartly.
Send us 3 photos (gate bottom front view, profile side view, connection/sensors) + 2 dimensions – and you'll avoid incorrect orders.
contact
Gate systems: Opto, DW, 8k2 – briefly explained
Opto-System
Optical closing edge: The sensor works optically. The profile must accommodate/guide the sensor. Advantage: modern solution, clean, fast. Disadvantage: incorrect profile = problems.
Relevant category: Optosensors & closing edge protection
DW (pressure wave system)
Mechanical: The pressure wave is located in the chamber. It is triggered by pressure/squeezing. Chamber dimensions, plugs, and clean end seals are important.
8k2 (8.2 kΩ)
Electrical system: a safety edge is evaluated via resistance/connection. Advantage: clearly measurable and easily testable. Disadvantage: connection errors are a common problem.
Comparison table: Opto vs DW vs 8k2
| system | How recognizable | What needs to fit? | Typical mistake | If you want it done right |
|---|---|---|---|---|
| Opto | Sensors/cable routing in the profile | Profile type + sensor technology + guidance | “Some kind of floor rubber” ordered | Measurements + photo, then match |
| DW | Round chamber (pressure wave) | Chamber size + plugs/ends | Plugs missing / wrong size | Select profile + accessories together |
| 8k2 | Electric safety strip | Connection/Start/End + Test | Incorrect connection, no check | Install and test the system cleanly. |
Important: If the gate is used in a commercial setting or is security-relevant, please do not use a "trial and error" approach. You won't save a single euro – only time and frustration.
Floor rubber vs. gap seal vs. threshold – which is right when?
Floor rubber / floor profile
The classic feature on sectional doors: it sits in the profile and seals the bottom edge.
Gap sealing (at the bottom)
If the gap at the bottom is “unfairly” large or you want additional rodent protection.
Threshold / floor mounting solution
If the ground is uneven: sometimes a threshold is the most honest solution.
Uneven ground + soft profile = “will never be perfect”. Then you need a constructive solution.
Mini-decision
- Small gap + normal gate: bottom rubber
- Large gap / rodents / strong drafts: additional gap sealing
- Uneven ground: Check threshold/substructure
Measuring without guessing: these 7 points are decisive
1) Manufacturer & Gate Type
Hörmann, Crawford, Novoferm, Alpha Deuren… the manufacturer is often the fastest filter.
2) Profile recording / shape
How does the rubber base fit in the profile? Insertion, clamping, groove shape – a photo helps a lot.
3) System: Opto / DW / 8k2
This is not optional. This is the foundation.
4) Chamber size
With DW/Opto, the chamber size is decisive (e.g., round measurement). Incorrect measurement = doesn't fit.
5) Profile height
55 mm, 37 mm etc. affects sealing and ground pressure.
6) Gate width / length
Meter goods vs. roll goods: For private use, it's usually meter goods, for commercial use it's often roll goods.
7) Soil reality
Is the ground level? Sloping? Cracks? This determines whether you only need a profile or also a threshold/gap seal.
Measurement shortcut (honestly, it works)
- Photo taken from below, front view (gate closed)
- Photo from the side view of the profile
- Photo of connection/sensors (if present)
- 2 Dimensions: Profile height + chamber dimension/profile mount
Then: Get in touch – we'll tell you what's right for you.
Compatibility by manufacturer: Hörmann, Crawford, Novoferm & Co.
Manufacturer compatibility isn't a "marketing ploy," but a matter of genuine fit: profile mount, sensor system, and accessories differ. Knowing the manufacturer and system means you're already 80% done.
| Manufacturer | Typical topics | What should you pay attention to? | Recommended route |
|---|---|---|---|
| Hörmann | Opto/DW/8k2 depending on the system | Profile capture + sensor system | Select profile type + accessories together |
| Crawford / Normstahl | DW/8k2 is frequently used in industrial environments | Chamber size + plugs/ends | Think complete system |
| Novoferm | Note profile variant | Height/Chamber/Profile shape | Compare old part + photo |
| Alpha Deuren | Opto-profiles manufacturer-specific | Opto-guidance & fit | Manufacturer + profile photo = safe |
| Universal | Mixed systems | Dimensions matter everything | Measure instead of guessing |
You can find a suitable selection here: Floor profiles & seals
Product types: Bottom rubber seals, top rubber seals, side seals
Floor rubbers (Opto / DW / 8k2)
The main factor for a tight seal at ground level. Important: System + fit + ground conditions.
Top rubbers (head gasket/cylinder seal)
If drafts get in at the top or water damages the fall: Top rubber is often the underestimated fix.
side seals
Side gap = dust & wind. Side seal makes the gate “complete”.
Closing edge protection & sensors
If your system uses Opto/DW/8k2, you need suitable components – otherwise the gate will do what it wants.
Conversion block: Go directly to the categories
If you're not 100% sure: it's better to ask once briefly than to order incorrectly twice.
Safety before assembly: what you need to consider
Powerless & controlled
- Switch off the drive
- Secure the gate against movement
- No “violent” actions at the fitting
When sensors are involved
- Properly document Opto/DW/8k2 (photos)
- Perform a functional test after assembly.
- If unsure: Get support
And yes: briefly check the mechanics as well.
If the gate is stiff, every seal will suffer. So: take a quick look at the rollers and brackets.
Casters | Caster holders & hinges
Replacing floor rubber: step-by-step
The process is often similar – whether for a private garage or an industrial setting. Differences lie in the system (Opto/DW/8k2) and the accessories. Important: work cleanly. A "rough" approach can turn a simple replacement into a never-ending project.
1) Check the old part
- Photographing profile shape and image
- Identify system (Opto/DW/8k2)
- Note the dimensions: height, chamber, intake
2) Expansion
- Extract profile from recording (depending on system)
- Secure ends/plugs/connections
- Clean the bottom edge (dirt kills the seal)
3) Cutting
- Cut straight (clean cut = better sealing)
- It's better to start slightly longer than too short.
- When ordering accessories: Include plugs/ends in your planning.
4) Installation
- Pull/insert the profile evenly
- Neatly place the ends
- Close gate → Check seal pattern
Product teaser
If you want to go directly to the relevant selection: View floor profiles & seals
Opto: Cleanly resolve cable/sensor routing
What matters
- Cables/sensors must not be pinched.
- The lead must run “cleanly” (no kinks, no pulls)
- The profile must match the opto-image.
Typical mistakes (that you can avoid)
- Incorrect profile without matching chamber
- Cable routed too tightly → malfunction
- No test after installation → later “surprise”
You can find opto-accessories here: Closing edge protection / Optosensors
DW: Properly inserting plugs and ends
DW is simple – if you do it completely.
- The chamber dimensions must be correct (otherwise the pressure wave will be positioned incorrectly)
- End caps/plugs are mandatory
- A clean finish prevents dirt and incorrect reactions.
Error pattern at DW
- Goal reversed “for no reason”
- Closing edge triggers sporadically
- The profile is not sitting properly / is slipping.
In 8 out of 10 cases: wrong size or missing accessories.
8k2: Start/End Connection & Testing
The most important step: examination
8.2kΩ is measurable. And that's precisely why it's good: you can properly test its functionality. If you don't test after installation, you're working blind.
Typical errors with 8k2
- Connection reversed / incorrectly wired
- Start/end not matching
- Cable breakage / cable pull
Accessories & Systems: Closing edge protection
Top rubber seal & side seal: when is it worth it?
Top-quality rubber is worth it if…
- There is a noticeable draft upstairs
- Water is running in at the fall.
- you have heated halls/garages
Side sealing is worthwhile if…
- Dust blows in from the side.
- The gap is visible (light gap)
- you want to be “completely sealed”
If you want it really tight
Floor + sides + top is the combination that really works. And if the gaps at the bottom are extreme: add gap seals .
Error patterns: Gate stops, reverses, doesn't seal
| problem | Common cause | Quick check | Solution |
|---|---|---|---|
| Drafts/dust below | Profile worn out or too small | Check gap dimensions, check profile height | Replace the floor rubber with the correct type |
| Water is forced in | Uneven floor / profile too soft / too short | Check water flow at ground level | Threshold/Substructure + Profile |
| Gate reverses when closing | Closing edge/sensor does not fit | Identify system Opto/DW/8k2 | Matching profile + accessories |
| False trigger (sporadic) | Cable, plug, connector, dirt | Check ends/connections | Cleanly assemble + test |
| The seal is rubbing badly. | Gate doesn't run smoothly / Mechanism worn out | Check casters/holders | Repairing mechanics |
If, when looking at the error message, you realize: “I’m not sure what the system is” → don’t guess. Just ask .
Smart cross-selling (because it makes sense)
While you're down there: Check the rollers and hardware. A gate that runs crooked will destroy any seal faster.
Ball-bearing casters | Caster holders & hinges
Maintenance: This is how the seal lasts significantly longer
Cleaning (brief but regular)
- Remove dirt from the floor/profile
- No harsh chemicals (rubber doesn't like that)
- If in industrial settings: check more often (dust/chips kill faster)
Visual inspection
- Cracks / brittle areas
- Is the profile still properly seated in the base profile?
- Are the sensors/connectors undamaged?
If the gate is difficult to open
The seal is rarely the sole cause. Often: rollers/fittings.
View rollers
Practical examples: 3 typical everyday situations
Case 1: Workshop – Dust & drafts are annoying
Solution: Bottom rubber seal fitted correctly (not too small), side seal added. Result: significantly less dust and more pleasant working conditions.
Case 2: Industry – Gate stops while closing
Cause: System incorrect (Opto/DW/8k2) or missing accessory. Solution: Correct profile + clean connection + test.
Case 3: Private garage – water is leaking in
Cause: Uneven floor + profile too soft/too short. Solution: Threshold/substructure + profile + clean pressure.
Jump to relevant categories
Floor profiles & seals
Everything about bottom rubbers, top rubbers, side seals & accessories.
Closing edge protection / Optosensors
When sensors and safety are relevant at the gate closure.
Gap seals for sectional doors
If the gap at the bottom is large or you want additional rodent protection.
Matching & Consulting
Measurements + photos → you get the right recommendation instead of guesswork.
Here's how to proceed (short & effective)
- Clarify system: Opto / DW / 8k2.
- Take 2-3 measurements: profile height + chamber dimension/profile mount.
- Take a photo: profile side view + connection/sensors.
- Select appropriate components: floor profiles & seals and, if necessary, closing edge protection .
- If you're unsure, just ask – then it'll be fine.
Doing it right once equals lasting peace. Anything else is just busywork.
FAQ
1) How do I know if I need Opto, DW or 8k2?
The safest method is via photo + connection/sensors. Opto has sensor guidance, DW has a pressure wave chamber, 8k2 is electrical with a resistor system.
2) Can I simply buy “a rubber floor mat” if it's just a draft?
If no sensors are affected: sometimes yes. If the closing edge/safety is involved: no, then the system and fit must be correct.
3) Why does my gate suddenly stop when closing?
Often the problem is with the closing edge/sensor: incorrect profile, connection error, cable problem or missing accessories.
4) What is particularly important at DW?
Chamber dimensions + plugs/ends. Without clean end seals, malfunctions are very likely.
5) What is particularly important with 8k2?
Check the start/end connections correctly and test after installation. 8k2 is easily testable – use that.
6) How long should a rubber floor covering be?
Generally, the width of the gate (slats/sections) plus a clean finish. It's better to plan for a slightly longer length than to cut it too short.
7) Does a higher profile always help against drafts?
Not automatically. If the floor is uneven, you may need a threshold/substructure or additional gap sealing.
8) When do I also need a gap seal?
In case of large gaps, strong wind pressure, rodent problems, or if the ground is very uneven.
9) Does it make sense to replace the top rubber seal and side seals as well?
Yes, if you want a really tight seal. The bottom alone helps, but the sides/top complete the result.
10) Why is my new floor rubber rubbing?
Either the fit/profile height is incorrect or the gate does not run smoothly mechanically (rollers/fittings).
11) What should I also check at the gate while I'm working downstairs?
Rollers, roller holders, hinges – a gate that runs crooked will destroy seals faster.
12) Where can I find the appropriate floor profiles?
13) Where can I find the closing edge protection / optosensors?
Here: Closing edge protection / Optosensors
14) What do I need from you so that you tell me the correct profile?
3 photos + 2 measurements. Then you'll get a clear recommendation instead of guesswork. Contact us
15) Can I assemble this myself?
Often yes. For safety-relevant systems: document thoroughly, assemble correctly, test functionality – or seek expert assistance.
Next step
If you want to seal your walls now, do it right the first time: clarify the system, take measurements, and choose the right product. And if you're not 100% sure – perfect: just send us some photos and measurements, and you'll get the right solution without making a mistake.
Get in touch nowTormeister24: Technology that fits – and advice that really saves you time.
