Which shape for the venetian blinds?

Before the CDL slat, I always had the idea over the years to install an additional darkening system inside the bedroom. The house builder could also make a wall casing for this additional box inside, so that the system would mostly disappear. What do you think, Hangman, is the effort worth it or is it close to a roller shutter in terms of darkness? Your pictures look good, but still quite bright, our bedroom is located on the east/south corner.

Sounds pretty wild, and I wouldn’t do it. In the darkened photos in post #31, you can see that the light only enters from the sides and from below (the rest is reflection on the inside of the slat). And in the detail photos in post #47, you see where our problem lies: the side guide rail is mounted on the plaster, which is why the window frame and slat overlap only slightly. And the windowsill reflects especially strongly in natural aluminum. Talk to your house or window builder to see if they can plaster the guide rails flush with the surface. That would increase the overlap of the window frame/slat and reduce the lateral light entry. The same applies to the bottom: the lower the blinds go, the better. Additionally, a dark windowsill should help here as well.

I think nuances in the anthracite tones are bearable

I do too, but in my observation we are in the minority: many homeowners expect an anthracite tone to be a pure delicate black metallic, consider a RAL number as the highest court color tone guarantee, and perceive the slightest bluish tint as comparable to a murder attempt on a nut allergy sufferer.

Talk to your house or window builder to see if they can plaster the guide rails almost flush, which would increase the overlap between the window frame and the slat and reduce the lateral light entry. The same applies at the bottom: the lower the blinds go, the better. Additionally, a dark windowsill should help here as well.

Thank you for your answer! I’ve looked at your pictures again and unfortunately still can’t follow your advice. In your case, the guide rails are plastered on the side, right? Doesn’t the light come in laterally from the gap between the guide rail and the slat?

[ATTACH width="149px" alt="20211029_100202_resized.jpg"]66531[/ATTACH]

Unfortunately, it’s clear at the bottom that your bottom rail probably will not rest on the windowsill; here lies the actual difference to the roller shutter, which optionally has a rubber seal at the bottom for contact. Or does the bottom rail on the CDL slat have a seal here as well? Could the bottom rail even travel all the way down to the windowsill? There seems to be an end cap there, right?

Thank you for your reply! I have looked at your pictures again and unfortunately still cannot follow your advice. In your case, the guide rails are plastered on the sides, right? Doesn't the light come from the gap between the guide rail and the slat on the side?



At the bottom it is clear, your bottom rail will probably not rest on the windowsill, here there is probably indeed a difference to the roller shutter, which (optionally) has a rubber seal at the bottom to rest against something. Or does the bottom rail of the CDL slat also have a seal here? Could the bottom rail even reach the windowsill? There is an end cap visible there, isn't there?

Plastered yes, but not flush plastered. You can see that the visible part of the side window frame is significantly smaller than the frame itself (for example, the lower frame part). That means the gap you described is relatively close to the window glass. If the guide rail were flush with the reveal, the light gap would move outward. Ergo – according to my theory – less light would reach the glass surface.

With venetian blinds, there is no defined bottom edge, as it depends on the respective inclination. There is also no bottom rail – all slats, including the lowest one, look the same. Resting on the windowsill will therefore not be possible, but it can certainly be done so that the venetian blinds extend further down than with us.

In summary: the more outside, the further down, the darker ;)

Already plastered, but not flush someplastered. You can see that the visible part of the side window frame is significantly smaller than the frame itself (for example, the lower part of the frame). That means the gap you described is relatively close to the window glass. If the guide rail were flush in the reveal, the light gap would shift outward. Ergo – according to my theory – less light reaches the glass surface.

Now I understand what you mean!! Thanks!!!! For you, the guide rail is flush with the edging of the windowsill; you would have preferred it to be flush with the rear edge of the frame. This will probably be problematic due to the light at the reveal since then the window would presumably have to be doubled on the side (all conjecture, I have no idea about window construction). But never mind, I understood you and will talk to the relevant parties; maybe it can at least be arranged so that the gap is closer to the frame than in/on the glass. Your pictures help me a lot in explaining the problem...

With venetian blinds, there is no defined lower edge, as this depends on the respective tilt. There is also no bottom rail – all slats, including the lowest one, look the same. Therefore, placing them on the windowsill will not work, but it can certainly be done so that the blinds extend lower than with us.

In summary: the more outside, the lower, the darker ;)

In your picture, one could think there is a bottom rail at the very bottom.



Theoretically, one could imagine that the venetian blind (provided enough slats were installed) can still be adjusted in height. But it looks to me as if an end cap is attached to the underside of the guide rail in your case, which ensures that the bottom rail cannot be pulled out, i.e., it only goes as far as resting on it. Since the guide rail in your case ends at the edging of the windowsill (and presumably this is always the case), the bottom rail is thus limited and could not reach the windowsill.
Solution: notch out the windowsill, set the guide rail lower. Problem: water behind the windowsill, runs into the plaster → very bad :D.

Can you also tell me if the bottom rail stays horizontal, or does it tilt, meaning with the slats vertical in the lower end position?

On your picture, one might think there is a bottom rail at the very bottom.



Theoretically, one could imagine that the venetian blinds (provided enough slats are installed) can still be adjusted in height. However, in your case, it looks as if there is an end cap attached to the underside of the guide rail that ensures the bottom rail cannot extend, i.e., it only moves up to a stop. Since the guide rail ends at the edge of the windowsill (and this is probably always the case), the bottom rail is limited and could not reach the windowsill.
Solution: notch out the windowsill, lower the guide rail. Problem: water behind the windowsill runs into the plaster --> very bad.

Can you still tell if the bottom rail remains horizontal or if it tilts, i.e., with the slats vertical in the bottom end position?

Potsblitz, you are right - there is a bottom rail. And yes, it ends at the edge of the windowsill (or the lower edge of the window frame). And since there is still a stopper there and the newly discovered bottom rail runs in a carriage, there is probably about 4 cm of space at the bottom. Somewhere in the thread there was also talk about natural stone windowsills; maybe it is tighter there because they have no edge? By the way, the bottom rail remains horizontal and is in its deepest position when darkened... at least!
One makeshift solution would be to glue a sealing lip or similar to the underside of the bottom rail that rests on the windowsill. However, I would rather assume that ROMA has encountered this issue quite often and has a solution ready.

One more thing about the profile widths of the windows and sliding doors: the frame width of the sliding door bothers me mainly because it brings the glass surface so far down. We have 2.25 m window height, which is actually generous. However, if 20–25 cm of frame is deducted, the glass is only 2–2.05 m high, which impairs the view (we look at a mountain ridge) (at least when I stand far back in the room). Hence the suggestion to briefly consider at what height the glass surface ends when selecting the windows.