How to Convert a Flat Ceiling to Vaulted

Vaulting existing ceilings is a big job, but the results are worth it—here's how

Building a Vaulted Ceiling

GeorgePeters / Getty Images

In This Article
Project Overview
  • Working Time: 1 - 2 wks
  • Total Time: 3 - 4 wks
  • Skill Level: Advanced
  • Estimated Cost: $15,000 to $30,000

A vaulted ceiling creates a sense of openness and space in a home. Even though the footprint of the home remains the same, vaulting a ceiling with trusses makes the house feels larger and airier. When combined with skylights and windows, a vaulted ceiling introduces more natural light to the home.

Flat ceilings (approximately 8-foot-high) built on a conventional truss system can, in most cases, be expanded upwards. Typically a project tackled by a contractor, the cost to convert a flat ceiling to a vaulted ceiling can run you $18,000 to $35,000, adding major resale value to your home. But with a little engineering know-how and some solid carpentry skills, this project can be tackled by experienced DIYers. Make sure to secure a permit to vault a ceiling before starting, and consult an engineer who can advise you on structural safety.

  • Trusses: Unified triangle-shaped elements above the ceiling that hold up the roof. Joists and rafters are parts of the truss.
  • Joists: Horizontal studs, usually two-by-fours, that run from side to side of the house. The ceiling drywall hangs from the joists.
  • Rafters: Sloped studs that form the top of the truss triangle.

Basics of Creating a Vaulted Ceiling From a Flat Ceiling

Whenever a home’s structural element is removed, another element must replace its function. Every part of a roof truss is crucial to the structural integrity of your home and must be attached to a load-bearing wall. Creating a vaulted ceiling means removing parts of the roof trusses. So, the removed pieces must be replaced in other ways. You can also remove ceiling joists when raising your ceiling, but you'll need to install temporary supports until the final structure is sound.

Structural Safety

One method of vaulting includes removing all pieces of the roof truss except for the rafters. To compensate for the missing pieces, the rafters are supported along their sides by two-by-ten boards that are nailed to the rafters—a process known as sistering. Adding two-by-tens to the rafters not only provides more structure, but also allows space between the roof and ceiling for insulation and light installation.

Sistering the rafters isn’t enough, so collar ties, or collar beams, must also be added. Collar ties are short studs that run horizontally from rafter to rafter, yet are located much higher and closer to the roof ridge than the ceiling joists. Essentially, the collar ties perform the same function as the removed joists, but on a smaller scale. These structural supports will always need to be put in place if you're raising a ceiling into the attic.

Roof Ventilation

Vaulted ceilings need to be appropriately vented to assure no heat builds up between the underside of the roof and the finished drywall. You can do so by installing soffit vents and gable vents to allow fresh air to move in and circulate. Soffit vents need to be installed in each rafter bay, making sure there is an intake and an outtake vent. Two gable vents on each side of the peak will also assure proper airflow and keep your roof dry.

VAC Ducts and Electrical Wiring

You'll also need to consider the ductwork and electrical rewiring when raising your roof. Both projects should always be tackled by a certified professional so that the end result functions properly and safely. You may want to attempt to move wires yourself, but to assure you pass inspection, it's best to hire an electrician. Additionally, a larger HVAC system may be needed to both heat and cool the larger open space. An HVAC professional can advise you appropriately.

Existing Chimneys

In most cases, existing chimneys don't pose a problem when vaulting a ceiling. Just make sure the part of the chimney that was originally housed in the attic is finished. If it was not, you'll need to add this expense to the overall cost of the project.

Alternative Construction

For the highest possible vaulted ceiling, joists can be cut to allow for a long continuous laminated wood beam to be placed in the attic area. The beam is jacked into place below the roof ridge. Each end of the beam is supported by vertical posts. The ceiling terminates in a peaked V-shape rather than a flat ceiling. 

What You'll Need

Equipment / Tools

  • Pneumatic nailer
  • Cordless drill
  • Circular saw
  • Electric miter saw
  • Reciprocating saw


  • Two-by-tens
  • Two-by-fours
  • Drywall
  • Insulation


How to Vault a Ceiling

  1. Clear the Attic

    Clear the attic by removing attic insulation, HVAC vents, lighting, and anything else resting on the ceiling joists.

  2. Demolish the Ceiling Drywall

    Remove the floor covering or leave in place if this is part of a whole-house remodel. Or lay down 1/4-inch plywood to protect the floors. Remove all of the ceiling drywall.

  3. Support the Roof

    Build a vertical support system that supports the roof while the work is being done. Usually, this is done by making a temporary wall out of two-by-fours that rests on floor. This wall runs the length of the roof ridge. If the floor is above a basement or crawlspace, additional support below the floor may be needed.

  4. Remove the Joists and Webs

    The joists and webs (smaller parts of the truss) are pulled out. In some cases, the joists are not removed entirely. Instead, they are cut away to leave a remaining 2 or 3 feet for the perimeter ceiling.

  5. Sister the Rafters

    The rafters are sistered with two-by-tens that are nailed to the sides of the rafters.

  6. Install the Collar Ties

    Collar ties are added to the tops of the rafters. The temporary support system can now be removed.

  7. Build the Perimeter Ceiling

    Create a perimeter ceiling for lights and to blend the vaulted ceiling in with the walls. This perimeter ceiling can be built from the ends of the cut joists or can be constructed from scratch.

  8. Run Wiring and Add Lights

    Electrical wiring for lights, such as gimbal recessed lights, is added to the ceiling. The lights are installed.

  9. Insulate the Ceiling

    Rigid foam, sprayed foam, or fiberglass insulation is added between the rafters. 


    Consult local building codes for insulation requirements.

  10. Install and Finish the Drywall

    Drywall technicians install drywall on the vaulted ceiling. After the drywall is hung, drywall compound (also known as mud) is applied and left to dry. The fully cured mud is sanded down smooth.

  11. Paint the Drywall

    A paint crew will paint the vaulted ceiling. They may construct a scaffold and move the scaffold around, as needed. Or they may paint the ceiling with paint rollers attached to long extension poles.

When to Hire a Professional

Vaulting the ceiling is nearly always a project for a general contractor. The contractor can coordinate with the architect and structural engineer, along with all of the tradespeople who contribute to building a vaulted ceiling. 

The contractor can also work with your local permitting agency and help see the permits through to successful completion.


If you are planning to do this work yourself or hire your own subcontractors, make a checklist of these items before starting the project:

  • Consult local building codes and be familiar with how they will affect your project.
  • Visit your city's website to familiarize yourself with the construction permitting process.
  • Plan on hiring an architect and/or structural engineer to assist with plans. Your city may require the involvement of either of these professionals to obtain a permit.
  • What are the benefits of a vaulted ceiling?

    A vaulted ceiling adds to the aesthetic of a home. Creating open space above increases the amount of natural light in your home, while providing efficient use of otherwise "dead space." The exposed beams sometimes required in vaulted ceilings also add character to your space, giving it a rustic appeal.

  • Do vaulted ceilings increase the electric bill?

    Always plan on having a higher electric bill in a home with vaulted ceilings. Vaulting a ceiling increases the amount of space that needs to be either heated or cooled, and demands more work from your heating or cooling system.

  • What is a half-vaulted ceiling called?

    Some home builders refer to a barrel-vaulted ceiling as "half-vaulted" because it looks like a barrel cut in half when viewed from below. While aesthetically pleasing, this type of ceiling construction should not be tackled by a DIYer and is usually reserved for churches and theaters for its acoustic properties.

    A half-vaulted ceiling can also refer to a ceiling that is only pitched on one side, similar to a shed roof. The construction mimics that of a fully vaulted roof, but the structural elements to carry the load may be different.

  • Are vaulted ceilings more expensive than flat?

    Vaulted ceilings are much more expensive than flat ceilings, but how much more varies by design. Vaulting a ceiling typically costs 5 to 20 percent more than building a flat ceiling, and can be even higher if the vault is elaborately customized.