ᐅ Cut ventilation ducts to the correct ceiling height

Hello everyone,

how did you cut your valve connections to the correct height?

Saw blade, reciprocating saw?
And do you stay slightly below the finished ceiling height (when drywall is installed on the ceiling)?

Thanks

Hi,

with the angle grinder and _before_ installation. They should be about 2 mm (0.08 inches) shorter than the finished ceiling. This ensures the valve sits flush against the ceiling.

If the connections are already installed, it's a bit tricky. A multi-cutter can work, but it's awkward and will wear out several saw blades.

Best regards,

Andreas

Hello Andreas,

Okay, all the connections have been installed for a long time.
Since I am drywalling the ceilings in all but two rooms and am about to start installing the gypsum boards, it seems shortening the outlets is still possible. Even in the rooms where the ceiling won’t be lowered, the surface will be fully skim coated, so a 2mm (0.08 inch) adjustment should be easily achievable there as well.
I will cut the outlets soon. If I use an angle grinder, I will have to cover the nearby windows because I’m afraid they might get damaged. That’s why I thought a reciprocating saw would be a smarter alternative.

Thanks for your response.

Micha

Hi,
I have a similar issue. For three wall outlets, I forgot to cut them to the correct length before plastering. They are currently about 15-20mm (0.6-0.8 inches) too long.
I wouldn’t want to use an angle grinder inside the house if I can avoid it. The sparks can get quite large and smolder for a while. That could easily burn a hole in a ceiling that’s supposed to protect your window. If you do use one, I would at least dampen the ceiling beforehand.

Best regards,

Andreas

In our case, it was done using a Dremel (or a similar tool, basically a small cutting disc). Since the pipes are made of plastic, there were no sparks. It was done right at the end because the pipes are closed, so no dust can enter during the construction phase.

What systems do you use?

The valve connections are basically a metal pipe protruding from above through the ceiling. It has a wall thickness of 1-1.5 mm (0.04-0.06 inches), so a small rotary tool like a Dremel is somewhat inadequate for the job... ;-)

Best regards,

Andreas