Is it possible to run an HVAC duct through a floor joist?

Floor joist cavities can make acceptable duct chases for insulated, air-sealed metal, flex, or fiberboard ducts.

How do you run a duct through a floor?

Fit the duct collar over the hole in the main duct and attach it. Cut a hole in the floor just large enough to accommodate the duct work. Run duct work through the hole. In the basement, secure the new duct work to a joist by running a hanger around the duct and attaching it to the joist.

How big of a hole Can I drill in a 2×8 floor joist?

You can put holes in floor joists anywhere along the length of the joist, but you can’t put them any closer than 2″ from the top or bottom edge of a joist. The maximum size of a hole is 1/3 the depth of the floor joist.

Can you cut floor joist?

You can cut a notch at the end of the joist to 1/4 of the joist’s depth (maximum). Along the outer third of a joist, you can cut a notch a maximum of 1/6 the joist depth and 1/3 the joist length without compromising its strength.

Where can you drill holes in floor joists?

You can drill the holes anywhere along the length of the joist (first photo). If you have manufactured I-joists, you can drill holes up to 1-1/2 in. diameter almost anywhere in the web area (the area between the flanges).

How do I add ductwork to upstairs?

Quote from Youtube video: Cut out your trunk. Notice I put some duct tape so I don't cut my arms. And then add the top take off you can add that from underneath you feed it from the top over notice I got some flex.

How do you reinforce joists with holes?

Quote from the video:
Quote from Youtube video: By adding a joist reinforce or you can double the size of the hole to a six inch diameter on either a two by ten or two by twelve. And according to testing this will actually make the joist. Stronger.

Is it OK to drill holes in floor joist?

You can drill the holes anywhere along the length of the joist (first photo). If you have manufactured I-joists, you can drill holes up to 1-1/2 in. diameter almost anywhere in the web area (the area between the flanges).

Does screwing into a joist weaken it?

When weight is applied to a joist, the top edge goes into compression while the bottom edge goes into tension. Improperly sized or placed holes and notches weaken the joist, make it bouncy and saggy, and provide an easy place for it to crack and fail.

What is the maximum size allowed for a drilled hole in a joist?

65mm

Maximum diameter of hole in any joist in any situation is 65mm.

What is code for drilling holes in floor joists?

IBC 2308.8.



Notches on the ends of joists shall not exceed one-fourth the joist depth. Holes bored in joists shall not be within 2 inches (51 mm) of the top or bottom of the joist, and the diameter of any such hole shall not exceed one-third the depth of the joist.

Can you notch the bottom of a joist?

Notches can only be made in the top OR bottom of the joists, (not both) within the permitted area to a maximum of 35mm. Holes may only be made on the joist’s centreline within the permitted area to a maximum diameter of 65mm.

Can you drill through engineered floor joists?

In engineered I-joists, you can drill holes up to 1-1/2 inch diameter almost anywhere in the web area between the flanges, provided they are at least 6 inches from the end of the I-Joist or load-bearing wall. You can drill holes up to 4 inches in diameter in the middle of the I-joist.

Can cold air returns be in the floor?

Return vents are usually larger than heat registers and can generally be found close to the ground or in the floor in older homes or on a wall close to a ceiling in newer homes. You will not feel air being blown out of these vents, as they are used to force out the cool air in the room to be reheated by the furnace.

How do you get warm air from basement to upstairs?

Quote from the video:
Quote from Youtube video: And hopefully it'll the fan upstairs will pull that cool air from the basement upstairs or in the wintertime it'll be warmer downstairs. And then they'll pull up the warmer air from the basement.

How far can you run flex duct?

Flexible duct shall be supported at manufacturer’s recommended intervals, but at no greater distance than four feet. Maximum permissible sag is 1/2 inch per foot of spacing between supports.

Is flex duct better than hard duct?

Flex ducts are better for existing trunk-and-branch heating and cooling systems. This is because they’re more versatile and flexible. Metal ducts are more rigid due to the nature of steel, making them ideal to build an entire HVAC system.

Does Flex duct reduce airflow?

If you’ve ever seen kinked or sagging flex duct and wondered whether that was a problem, you were onto something! Since flex duct, by definition, is flexible, it often flexes in ways we don’t want it to. The result is poor airflow and ineffective HVAC systems.

How long can a duct run be?

If you choose well, you can be at 10 or 20 feet of effective length. If you choose that smooth mitered elbow, however, you end up with 75 feet.

Does length of duct affect cfm?

Texas A&M did a study on the effect of flex duct not pulled tight and the results are astounding. In my article on this research, I showed from their results that a 6″ duct moving 110 cfm when pulled tight will move only about 70 cfm with 4% linear (longitudinal) compression and about 40 cfm or less at 15% compression.

How many CFM can a 12 inch duct handle?

CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)