How to Install a Range Hood on a Slanted Ceiling


An apartment kitchen, highlighting the range hood on a slanted ceiling.

Range hoods keep your home clean by filtering grease and food particles out of the air while cooking. But, if you have a slanted or sloped ceiling, actually completing the installation can be challenging. After all, most fume hoods are intended to hang from the ceiling. What can you do about it? 

Luckily, installing a range hood on a slanted ceiling is relatively easy. In most cases, all you have to do is cut into the ceiling and run your range hood into it. You can then mount the hood itself horizontally. 

How to Install a Range Hood on a Slanted Ceiling

There are three basic ways to install a range hood on a slanted ceiling. All three involve some additional construction over simply installing the hood. Unfortunately, there’s no such thing as a range hood for a sloped ceilings, unless you have it custom made. For example, sloped range hoods tilt to the front and this does not affect the cap which should rest against the ceiling. Instead, you’ll have to cut or build a solution. 

Here, these options are: 

  • Cut into the ceiling 
  • Cut the range hood 
  • Build a soffit box

Here, all three options require significantly different work, so we’ll cover each of them separately. 

Install the Chimney in the Ceiling 

The easiest way to install your vent hood on an angled ceiling is to cut directly into the ceiling. Here, you can determine where you want the chimney, measure it out, and then get started.  

What You’ll Need: 

  • Chalk or pencil 
  • Utility knife
  • Jigsaw or reciprocating saw 
  • Sturdy piece of wood you can cut to size between joists in the ceiling
  • Screws
  • Power drill 
  • Level 
  • Ladder 
  • Measuring tape 

From there, you can get started installing your vent hood chimney in the ceiling. 

  1. Decide where you want the range hood. Position it and run the vent hood chimney up to the ceiling.
  2. Use a chalk or a pencil to trace around it, starting with where it touches the ceiling.
  3. Measure the diameter of the range hood and double check the markings.
  4. Then use a box knife to start a hole in the ceiling. Cut on the outside of the lines you drew. The hole should be slightly bigger chimney. You can also use the box knife to take the full drywall out. However, a reciprocating saw or jigsaw is a faster alternative.
  5. Remove the drywall from the hole you cut. 
  6. Use a drill and screws to attach a level wood block above the hole. You can use a small level if you can get it into the hole. Otherwise, measure the distance to the floor on each side of the block to ensure its level.
  7. Hang the range hood as normal on the wall. Then, run your chimney up, attaching the top bracket to the wood you’ve just hung. The chimney should be a slightly tight fit into the drywall. However, you’ll still want to run a bead of caulk around the edges. 

This option is easy, looks relatively professional, and doesn’t require any special tools or a lot of labor. That makes it the easiest option if you want to quickly get your installation over with. 

Cutting your Range Hood Chimney 

The second easiest way to install a ranged hood with a slanted or sloped ceiling is to cut the chimney. This requires a bit more math than cutting the ceiling. In addition, you shouldn’t use this method if your extractor hood chimney has brackets on the top. On the other hand, if you have a separate bracket panel that screws onto the chimney itself, you can go ahead with it. If your brackets are on the back, you don’t have to worry about it. 

What You’ll Need: 

  • Chalk or pencil 
  • Utility knife
  • Screws
  • Power drill 
  • Level 
  • Ladder 
  • Measuring tape
  • Pen and paper 
  • Tin snips or jigsaw with a metal blade

Here, the most difficult part will be calculating the angle to cut the chimney for the sloping ceiling. To do this, you’ll have to take several measurements. A good level with a center bubble will be essential. 

  1. Measure the distance from the range hood to the top of the ceiling, on each side of the chimney. Measure this out and mark it on the chimney using a marker, pencil, or chalk. 
  2. Use a chalk or pencil to mark where the chimney should be on the ceiling. The easiest way to do this is to hold the chimney piece with one side level against the lower end of the ceiling and then mark the points with a pencil. Use the level to trace those points to a square or rectangle. 
  3. Measure from each of those points to the floor and write that down.
  4. Then, place a level on the ceiling on each size and make a note of the exact degree the ceiling slopes. If you don’t have a level with degrees marked, use a chalk to mark the start and end of the bubble. 
  5. Measure from the range hood to the chimney where you’d like it cut and mark each corner – taking care that you’re measuring in alignment with how you’d like the chimney on the ceiling. You have a high end and a short end and they should be on the correct sides and not the front or the back. 
  6. Double check that the differences in measurement align with the differences in measurement from the floor to the ceiling that you took earlier. Double check this by ensuring that the angle is tilted to the same degree as the ceiling is. 
  7. Then, take tinsnips or a saw with a metal blade, a jigsaw or even a metal bladed hacksaw will do, and cut the chimney at the angle. Here, you’ll want to do the low side first, then the high side, then the two angled sides. 
  8. Hold your chimney up to the ceiling and make sure it fits. 
  9. Use a file or sandpaper to smooth out any rough metal, being careful not to scratch the rest of the hood. 
  10. If you have a top bracket for the extractor hood chimney, you’ll likely have to slightly cut the bottom corners to get it to fit on crooked. Then, use screws to attach it to the chimney. 

From there, you can continue to attach the range hood following the normal manufacturer’s instructions. 

Installing a Soffit Box on a Slanted Ceiling 

The third option for installing your extractor hood with a sloped ceiling is to install a soffit box. A soffit box is an artificial dropdown in the ceiling, intended to provide a base for the hood. These are ideal if you have a very high or vaulted ceiling, if the ceiling is very slanted, or if you just don’t like the look of the vent-a-hood being crooked. 

Here, you can make a soffit box of any size you want. For example, some people will install a range hood over a kitchen island. In this case, you might want the soffit to be the same size as the island, for balance. In other cases, the soffit can be the slightly larger than the chimney itself. It’s up to you and what looks good in your kitchen. 

Things you’ll need: 

  • Drywall 
  • Utility knife 
  • Pencil 
  • Measuring tape
  • Level 
  • Jigsaw or reciprocating saw 
  • Plaster 
  • Paint 
  • Drywall tape 
  • 2×4 lumber 
  • Drill
  • Wood screws

Here, you’ll essentially be building a box. It’s usually a good idea to do this with help. However, you won’t likely need help till the last stages of putting the soffit box into place. 

  1. Measure the size of the box. Here, you want to take into account how large you want the box, how deep it should be, and why it has to be there. E.g., is it balanced with something underneath it? How long is your chimney? What length looks good? Often, soffits are built at least 84 inches off the floor. That means you’ll have a 12” soffit if you have an 8” kitchen. 
  2. Mark the dimensions of the desired soffit box on the ceiling and trace those lines.
  3. Use a utility knife to start the cuts in the drywall then use a saw to cut the drywall out. Either cut the drywall in small sections or have someone hold it up while you cut to avoid having it fall out – which could rip out a large section of the drywall. 
  4. Check the joists. You’ll want to install crossbeams between the joists, so you can adequately support the Soffit box. These should be simple 2×4 beams between the joists on each side of the soffit box. Use wood screws to drill these into the ceiling joists.
  5. Measure from the joists to floor on each side of the box. Write those measurements down. Deduct the desired height from the floor to the soffit box from the measurement. E.g., if you’d like 84 inches between the floor and the soffit box, deduct that from the measurement.
    For example: 1: 101 inches to the floor – 84 = 17

    2: 101 inches to the floor – 84 = 17

    3: 97 inches to the floor – 84 = 13

    4: 97 inches to the floor – 84 = 13

    In this example case, you’d cut two boards at 17 inches and two at 13 inches.

  6. Then, you want crossbeams and side supports. These should simply be the length and width of the soffit box. If you have a soffit box that’s more than a foot wide, you’ll also want to add supports about every foot on each side. And, you’ll want at least one center brace to support the range hood itself.

    Here, you’ll also want to keep the long boards on the outside and the short boards on the inside. The inside boards should fit into the corners of this box, to suspend it. Cut 2x of this, to go around the top and the bottom of the box.
  7. Attach everything together using screws. Have someone hold it for you. Then, have someone hold it in place against the ceiling. Make sure the supports are in place against the joists. You can use screws to put them in to be sure. Then, use a marker or a pencil to mark the ceiling line on each side. Take the box back out. 
  8. Measure the lines you made on the box and use that to cut drywall to fit. Make sure the drywall fits on the box. You’ll want four sizes and a bottom panel. Here, it’s important to cut the top layer of drywall first to avoid tearing the paper. 
  9. Then, hang the soffit box. 
  10. Put a bead of caulk on the boards and hold the drywall up. Attach it with drywall screws. Make sure you have one or more people helping you do this work. 
  11. Tape the edges the soffit box and plaster it.
  12. Mark where you want to hang the range hood and pre-drill holes. 
  13. Finish the plaster on the box, sand it, and then paint the box to match the ceiling.

From there, you can hang your extractor hood following the manufacturer’s instructions. 

Frequently Asked Questions 

If you still have questions about hanging your range hood, this FAQ might help. 

Can you put a range hood in a vaulted ceiling? 

Yes, but you normally need a Soffit box to do so properly. Otherwise, you might want to extend the chimney and cut it to match the angle of the ceiling. 

Can you vent a range hood sideways? 

That depends on the extractor hood. For example, some require venting directly upwards. However, most allow you to install a corner or flexible ducting anywhere you’d like. 

Can you install a range hood without a vent? 

You can always install a recirculating range hood. These hoods simply filter air through a washable filter, rather than venting it outside. This removes the need to actually vent the hood, but does mean you’ll have to maintain the filter. 

Can I use flex duct to vent a range hood? 

Flex and semi-rigid ducting works to vent a range hood. However, it’s not as durable as rigid ducting. If you do install it, you should expect to replace it more quickly. 

Conclusion 

Installing a range hood on a sloped ceiling will always take more time than installing one on a flat ceiling. However, you do have three options to hang your hood. And, hopefully that allows you to install the hood in a way that looks good in your kitchen. 

Good luck with the installation.

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